Beginner Seasoned
Pick your zone and the dates re-calibrate.
The Guide Crops Vol. 003

Brussels Sprouts

in Zone 9, this week

Brussels sprouts grow as small cabbage-like buds along a tall stalk, and you pick them a few at a time from the bottom up. They take a long time, about 3 to 6 months, and taste best when they mature in cool fall weather. Frost makes them sweeter, so the best sprouts come after the cold sets in. Summer heat makes them loose and bitter, so they are really a fall and winter crop. Brussels sprouts are a cool-season brassica grown for the small, cabbage-like buds that form in the leaf axils along a tall central stalk, harvested progressively from the bottom up. A long-season crop needing roughly 90 to 180 days, it is timed to mature in cool fall and winter weather: heat gives loose, bitter sprouts, while frost actually sweetens them, so the best sprouts come after the first hard frosts. It is one of the most cold-hardy garden vegetables, standing in the garden into early winter while temperatures hold above about 20°F.

Brussels Sprouts mature plant
Fig. 01 · Brussels Sprouts, mature Zone 9
Mature in
90-180d
from transplant
Sunlight
Full sun
6-8 hrs daily
Water
Regular
1.5 inches / week
Spacing
18 to 24 in
between plants
Soil pH
6-7
slightly acidic
Today · in your zone

What's happening right now

October 21 · Zone 9 · Stage 01 · Germination

Off-season for brussels sprouts in zone 9.

Seasoned
Microclimate · Zone 9a vs 9b

Your zone, at a finer grain

Zone 9 averages a last frost around March 1. Within Zone 9, the colder half (9a, winters down to 20°F) runs about a week later. The warmer half (9b, winters down to 25°F) runs about a week earlier. The plant app picks your subzone from your ZIP.

SubzoneLast springFirst fallGrowing daysWinter minFruits reliably
9aMar 8Nov 24~26120-25°FYes · two seasons
9bFeb 28Nov 30~27525-30°FYes · two seasons

Averages from 8 weather stations per subzone, drawn from NOAA 1991-2020 Climate Normals. Your actual frost date can vary by up to two weeks based on elevation, proximity to water, and local topography.

Source: NOAA 1991-2020 Climate Normals Methodology
Your climate region in Zone 9
The season at a glance

Planting calendar

In Zone 9, brussels sprouts can be planted July through August. Start indoors Jun. Harvest runs November through February.

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
plant
too late
too early
too early
too early
too early
indoors
plant
plant
too late
too late
too late
too late
harvest
harvest
harvest
harvest
harvest
indoors
plant out
harvest
Seasoned
Stagger your sowings

Succession planting

Brussels sprouts grow for a long time, so most gardeners plant just one crop and pick from it for weeks, rather than planting in batches. In mild areas with a long cool season you can stagger a couple of plantings a month apart. The key is to plant so the sprouts form in cool fall weather; in hot areas, skip summer and grow them for fall and winter.Brussels sprouts are largely a single long-season planting rather than a true succession crop: each plant holds the bed for months and is harvested progressively up the stalk. In short-season regions, set out one crop and let it ride. In long, mild regions such as the cool coast you can stagger a couple of sowings about a month apart to spread the harvest. Time plantings so the sprouts form in cool weather; in hot regions skip summer and plant for a fall and winter crop.

Every 4 weeks · sow a short new rowUp to 4 sowings a seasonToo hot to sow midsummer
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
sow
harvest
keep sowing
too hot
continuous harvest
The season, mapped

Seed to garden

Brussels sprouts take a long time to grow, so it is easiest to start them as transplants. Sow seeds indoors about 5 to 6 weeks before you plant out. In cold areas, plant out in late spring or early summer so they mature in fall. In warm areas, plant in late summer or fall for a winter crop. Let homegrown seedlings get used to the outdoors over a week before planting.Brussels sprouts are almost always transplanted because of their long season. Start seeds indoors about 5 to 6 weeks before set-out. In cold regions, sow in spring and transplant in late spring or early summer to mature in the cool fall; in warm regions, sow in mid to late summer and transplant in late summer or fall for a winter crop. Set out sturdy young plants with about 4 to 6 true leaves and harden them off over 7 to 10 days.

  1. 01
    Sow indoors →
    Jun
    Start about 5 weeks before your last frost
  2. 02
    Transplant out →
    Jul - Aug
    After hardening off
  3. 03
    First harvest
    From Nov 1
    90-180 days from transplant
Start method
Transplant
Soil temp
45-85°F
Hardening off
7-10 days
From seed to fruit

The growing journey

Stage 01 · Germination
01
Germination
Days 7-14 · current stage
In about 5 to 10 days, your seeds sprout and push up their first two little leaves (the seed leaves).Seeds sprout in about 5 to 10 days, pushing up two seed leaves (cotyledons). Brussels sprouts are started indoors for transplanting because of their long season.
Keep the starting mix damp. Once the first real leaves appear, give the seedlings strong light so they do not get leggy.Keep the starting mix evenly moist and give bright light from emergence to avoid stretch; thin or pot up once the first true leaves appear.
FROM PLANT · Start seeds indoors about 5 to 6 weeks before you plan to plant them out.Start seeds indoors about 5 to 6 weeks before set-out; brussels sprouts are transplanted, not direct sown, because of their long season.
FROM PLANT · Plant the seeds about a quarter to half an inch deep, keep them damp, and give them strong light so they do not get leggy.Sow about 0.25 to 0.5 inch deep into a moist starting mix and give bright light from emergence to keep seedlings stocky.
02
Seedling
Days 14-42
The seedlings grow their real leaves and a stronger stem. They are ready to plant out at about 5 to 6 weeks old, with several true leaves.Young plants build true leaves and a sturdy stem; transplants are ready at about 4 to 6 true leaves, roughly 5 to 6 weeks from sowing. Set out sturdy young plants rather than oversized ones.
Harden the seedlings off over about a week before planting out. Watch for flea beetle holes on the young leaves.Harden off over 7 to 10 days before setting out at the wider 18-to-24-inch spacing; protect seedlings from flea beetles and cabbage root maggot with row cover and collars.
FROM PLANT · Space plants about 18 to 24 inches apart, with wide rows, since they get big. Harden the seedlings off over about a week before planting out.Transplant sturdy young plants with 4 to 6 true leaves at 18 to 24 inches apart in rows 24 to 36 inches apart; harden off over 7 to 10 days first.
FROM PLANT · Cover young plants with a row cover to stop flea beetles, and put a collar around the stem to keep root maggots out.Protect transplants from flea beetles with row cover and from cabbage root maggot with stem collars, especially in cool, wet soil.
03
Established
Days 42-120
The plant grows into a tall, leafy stalk over the summer (in cool regions) or fall (in warm regions). This is when it builds the frame that will carry the sprouts.The plant builds a tall, leafy stalk over several weeks, laying down the frame whose leaf axils will later carry the sprouts. Steady growth now sets the yield; the stalk does not form sprouts until cool weather arrives.
Feed with nitrogen and keep it evenly watered so it grows steadily. Firm the soil around the base and stake tall plants. Check for aphids and caterpillars.Side-dress with nitrogen, keep moisture even, firm and hill the soil at the base, and stake the top-heavy stalk. Scout for cabbage aphids, caterpillars, and harlequin bugs as the frame fills out.
FROM PLANT · Feed with nitrogen and water steadily while the stalk grows tall, and stake it so it does not blow over. Firm the soil around the base.Side-dress nitrogen as the stalk builds and keep moisture even at about 1 to 1.5 inches per week; firm and hill the soil at the base and stake the top-heavy plant against lodging.
FROM PLANT · Check the new growth for aphids and under the leaves for green caterpillars, and deal with them early before the sprouts form.Scout the growing tips and leaf axils for cabbage aphids and the undersides for caterpillars; getting ahead of aphids now keeps them out of the sprouts later.
04
Sprout formation
Days 100-160
As the weather cools, small buds like tiny cabbages start to form where each leaf joins the stalk, beginning at the bottom and working up. This is the crop forming.Sprouts form in the leaf axils up the stalk as cool weather sets in, maturing from the bottom upward. Heat here gives loose, leafy, bitter sprouts, so the plant should be timed to reach this stage in cool fall or winter weather.
Many gardeners snap off the lowest leaves as the sprouts swell. When the bottom sprouts are about an inch across, you can cut off the very top of the plant (top it) to push the upper sprouts to size up more evenly. Ease off heavy nitrogen now.Remove lower leaves as the sprouts swell to give them room. Optionally top the plant (cut out the growing point) when the lowest sprouts are about 1 inch across, less than 60 days before harvest, to even up and hasten the upper sprouts; ease off nitrogen so sprouts stay firm rather than blowy.
FROM PLANT · Pull off the lower leaves as the sprouts grow, and when the bottom sprouts are about an inch across you can cut off the very top of the plant to push the rest to size up evenly.Strip the lower leaves as sprouts swell to give them room, and optionally top the plant (remove the growing point) when the lowest sprouts are about 1 inch across to even up and hasten the upper sprouts.
FROM PLANT · Once the sprouts start forming, go easy on the nitrogen, because too much makes loose, leafy sprouts and brings aphids.Ease off heavy nitrogen once sprouts set; late lush growth gives loose, blowy sprouts and draws aphids. Even moisture keeps them firm.
05
Harvest
Days 125-215
The lowest sprouts firm up to about 1 inch across, tight and deep green. They keep ripening up the stalk over several weeks, and they taste best after a frost.Sprouts reach harvest size (about 1 to 1.5 inches, firm, tight, deep green) from the bottom of the stalk upward, beginning roughly 90 days from transplanting and continuing for weeks. Frost sweetens them; mature plants hold while temperatures stay above about 20°F.
Twist or snap off the firm sprouts from the bottom up, taking the leaf below each, and leave the smaller ones up top to keep growing. Keep picking up the stalk through fall and into the cold.Snap or twist the lowest mature sprouts and strip the leaf below each, working up the stalk over several weeks; harvest the best sprouts after a frost or two. In the coldest zones, cut the whole stalk before a hard freeze and store it cool.
FROM PLANT · Pick from the bottom of the stalk up. Twist off the firm, tight sprouts about an inch across and take the leaf under each, leaving the smaller ones up top to keep growing.Harvest from the bottom up: snap or twist the lowest firm, tight sprouts (about 1 to 1.5 inches) and strip the leaf below each, leaving the upper sprouts to keep sizing up over several weeks.
FROM PLANT · Brussels sprouts taste best after frost, and the plant keeps them well in cold weather. Before a really hard freeze, cut the whole stalk and store it somewhere cool.Sprouts are sweetest after a frost or two; mature plants hold while temperatures stay above about 20°F, and a whole stalk can be cut and stored cool before a hard freeze.
Beginner
Know your soil

Your soil

Identify yours

Not sure what soil you have? Grab a small handful of damp soil from your garden bed and squeeze it. If it crumbles apart easily, it's sandy. If it holds together but breaks when you poke it, it's loam (what most vegetables want). If it stays in a hard, slippery ball, it's clay.

What this crop wants

Brussels sprouts like rich, fertile soil with plenty of compost worked in, and they do best in firm, settled ground rather than loose, fluffy soil. Loose soil tends to give loose, open sprouts, so firm the bed before planting and keep it evenly moist but never waterlogged.

If your soil doesn't match

You have sandy soil

Mix 2-3 inches of compost into the top 6 inches of your bed before planting. Compost holds moisture (which sandy soil drains too fast) and adds the nutrients sandy soil tends to lack. Repeat each season. Compost breaks down over time.

You have clay soil

Mix 2-3 inches of compost AND a few inches of coarse sand or perlite into the top 6 inches of your bed. The compost feeds the plants; the sand breaks up the clay so air and water can move through. Don't add sand without compost. It can compact like concrete.

Containers and raised beds

If amending your soil sounds like too much work, or if your soil is heavy clay, full of rocks, or contaminated, build over it. A raised bed at least 12 inches deep filled with a 50/50 mix of compost and sandy loam gives you ideal growing soil with no battles. A 5-gallon container with quality potting mix does the same for one plant at a time. Both bypass your native soil entirely.

Learn more about your soil
The specs

Care guide

The numbers that matter, at a glance.

Sunlight
Full sun · 6-8 hrs/day
Water
Regular
Spacing
18 to 24 inches
Soil
loam, sandy loam
Days to maturity
90-180 days from transplant
Soil pH
6 to 7
Container OK?
Yes · 5+ gal pot
Germination temp
45-85°F
In a pot

Yes, 5 gallons and up

Brussels sprouts can grow in a large pot, but they are tall, top-heavy, long-season plants, so they are not the easiest container crop. Use a deep pot of at least 5 gallons, one plant per pot, stake it so it does not topple, and keep it well watered and fed. Pick sprouts from the bottom up.Brussels sprouts are a marginal container crop: they are large, top-heavy, and occupy the pot for months, so the gains of a container (mobility, soil control) come with real demands. Use a deep, heavy container of at least 5 gallons (10 is better), one plant per pot, stake the stalk against toppling, and keep moisture and feeding steady since a small soil volume runs out over a long season. The general container-vegetable guidance applies; brussels-specific container figures are modeled, not separately sourced.

Pot size
5 gallons and up; 10 gallons is comfortable
Mature size
2 to 4 feet tall, 2 to 4 feet wide
Drainage
Drainage holes are a must. Skip the gravel layer. Empty the saucer after watering so roots never sit in water; brussels sprouts resent waterlogged soil.
Watering
Pots dry out faster than the ground, so check daily in warm weather; a tall plant in a pot is thirsty.Containers dry faster than beds; check moisture daily in heat and water before the mix dries, since drought stress loosens the sprouts.
Depth and shape
At least 12 inches deep. Brussels sprouts grow into a tall, top-heavy stalk with a substantial root system, so choose a deep, wide-based container of at least 5 gallons and 12 inches deep for stability, and stake the plant. A broad, heavy pot resists toppling and buffers the fast drying a narrow pot suffers.
Self-watering pot
Yes. A self-watering container suits brussels sprouts well, since it smooths out the steady moisture that keeps the plant growing and the sprouts firm over a long season.
Mix
A rich, well-drained commercial potting mix high in organic matter. Blend in compost and a slow-release balanced fertilizer; container plants feed for months and exhaust a small soil volume.
Feeding
Container plants need more frequent feeding than in-ground ones because watering leaches nutrients over the long season.
One to try

Long Island ImprovedA dependable open-pollinated heirloom (about 90 days) with good production, eating quality, and storage; compact and a longtime garden standard. Seed-saveable, unlike the hybrids.

2 more compact types

HestiaA uniform, upright hybrid bred for tidy, even sprouts and good standing ability; widely grown for fall. Days to maturity approximate.

Jade Cross

Winter

In mild-winter areas, a brussels plant in a big pot keeps standing and producing through the cold; just move it to a sheltered, sunny spot and keep picking. In cold areas, the small soil volume freezes hard, so pull the pot against the house during deep freezes or harvest the whole stalk before the worst cold.Brussels sprouts are cold-hardy enough to stand through winter in a container in mild zones, holding their sprouts in a sheltered, sunny spot. In colder zones the limited root volume freezes harder than open ground, so move containers against a wall during hard freezes, or treat the potted crop as a single fall-into-early-winter planting and cut the stalk before deep cold.

Pot safety

Ask what your balcony or roof can carry

A balcony or roof can only hold so much weight. Before you set heavy pots there, ask a building architect what it can safely carry.Illinois Extension's guidance is to consult a building architect about weight limits before placing heavy pots on a balcony or rooftop garden. It gives no weight figure.

Never grow food in a container with anything toxic in it

Many kinds of containers can be used. Whatever you choose, keep anything toxic out of it, especially if you are growing food.Colorado State accepts nearly any container material but warns against using a container that holds toxic materials, especially for edible plants. Illinois adds that a vegetable container should be free of chemicals toxic to plants or people, and urges caution with treated lumber when growing food. If you cannot account for what a repurposed container once held, that alone is a reason to keep food out of it.

Secure hanging containers well

Fasten hanging baskets and window or rail boxes securely. Think about what is below them too, since they can drip on people or things underneath.Illinois Extension asks growers to secure hanging containers well and to think through the safety issues of hanging them. Placement matters too, since a hanging container can drip onto people or belongings below.

Soil chemistry

Soil pH for brussels sprouts

Preferred
6 to 7
Tolerated
5.5 to 7.5

Brussels sprouts grow best in soil that is slightly acidic to neutral, about 6.0 to 7.0. A simple soil test tells you where you stand. If you have had clubroot, keeping the soil closer to neutral helps hold it back.Aim for a soil pH of about 6.0 to 7.0; the plant still does fine across a wider 5.5 to 7.5 band. Clubroot, the key brassica soil disease, is far more likely below pH 6.5, so where it is a concern hold the soil toward the neutral end and lime acidic ground well ahead of planting.

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Steady hand on the hose

Watering

When & how much
Frequency
Water regularly so the soil stays evenly moist, roughly 1 to 1.5 inches a week.Give about 1 to 1.5 inches weekly, kept even through the long season.
Amount
Aim for roughly 1 to 1.5 inches of water a week.About 1 to 1.5 inches per week, a little more in hot, dry spells while the plant is sizing up.
Method
Water at the base of the plant rather than over the leaves.Water at the soil line with drip or a soaker hose where possible.
Signs of trouble
Too much water
Lower leaves yellow and the plant looks soggy and limp.Yellowing lower leaves and limp growth; brussels sprouts dislike waterlogged soil and can rot at the crown or fall prey to root maggots in cold, wet ground.
Too little water
Wilting leaves and small, loose, bitter sprouts.Wilting, stalled growth, and loose, bitter sprouts; drought stress during sprout formation directly hurts sprout quality.
Feeding rhythm

Feeding

Frequency
every 3 to 4 weeks
Type
Nitrogen-rich fertilizer
When to start
starter at transplanting, then side-dress about 4 and 8 weeks later

Brussels sprouts grow for a long time and need regular feeding. Mix a balanced fertilizer into the soil before planting, then feed with a nitrogen fertilizer about a month and again two months after planting. Once the little sprouts start forming, go easier on the nitrogen, because too much makes loose, leafy sprouts and brings aphids.Brussels sprouts are long-season heavy feeders that need steady nitrogen to build the tall, leafy stalk that carries the crop. Work a balanced fertilizer such as 10-10-10 into the bed before planting, then side-dress with nitrogen about 4 and 8 weeks after transplanting. Ease off heavy nitrogen once sprouts begin forming, since late, lush growth encourages loose, leafy sprouts and draws aphids.

N · P · K = 21-0-0

Use a balanced fertilizer like 10-10-10 at planting, then a nitrogen feed a month or two later.High N to build the stalk and leaves; a 10-10-10 starter worked in before planting, then a nitrogen side-dress such as 21-0-0 at about 4 and 8 weeks. Ease off N as sprouts set.

Try Blood meal, 21-0-0, or a balanced 10-10-10 vegetable fertilizer
Who grows well together

Companion planting

Brussels sprouts do well next to aromatic herbs, onions, and quick cool-season crops you can tuck in while the plants are small. The most important rule is to keep them away from other cabbage-family plants, which share the same pests and diseases. Most brussels sprouts companion pairings are traditional rather than trial-tested. The ones worth acting on are practical: aromatic herbs and alliums as scent-based deterrents for cabbage pests, small flowering plants such as sweet alyssum and dill to draw the parasitic wasps and hoverflies that attack aphids and caterpillars (a habitat tactic Clemson recommends for cole crops), and quick crops like lettuce that use the open ground while the slow brussels plants fill in. The well-grounded caution is to separate brussels sprouts from other brassicas, which share clubroot and the whole cabbage-family pest complex, a rotation and disease principle more than a tested adjacency effect.

Other
Sweet alyssum
Sweet alyssum makes lots of tiny flowers that bring in helpful insects which eat aphids, a major brussels pest.Sweet alyssum is one of the better-supported brussels companions because aphids are this crop's signature pest. Its low mats of tiny flowers are a classic insectary plant, drawing the hoverflies, lacewings, and parasitic wasps that prey on cabbage aphids and caterpillars, and Clemson specifically advises small flowers like alyssum near cole crops for biological control. Let it self-sow along the bed edge. Research-backed
Dill
Dill's flowers attract helpful insects that hunt the aphids and caterpillars that bother brussels sprouts.Dill works for brussels sprouts mainly through beneficial insects. Its umbel flowers draw the parasitoid wasps and hoverflies that attack cabbage aphids and the cabbage-family caterpillars, and Clemson lists dill among the flowers to plant near cole crops for natural control. Let some flower, and keep it off to the side so it does not crowd the big plants. Research-backed
Onions
Onions are a traditional neighbor for cabbage-family plants; their strong smell is said to help confuse and deter cabbage pests.Alliums are a traditional brassica companion, their pungent scent thought to mask the crop from the cabbage pests that hunt partly by smell. Shallow-rooted and undemanding, onions tuck around young brussels plants without competing for much. Treat it as a low-risk, scent-based aid rather than a proven control. Traditional
Leafy green
Lettuce
A quick, shallow cool-season crop that uses the open ground and light between young brussels plants and is harvested long before they fill in. Space-driven and traditional, not a documented growth effect; the two share no serious pest. Traditional
interplant along edges
Trap crop
Nasturtiums
Often planted as a trap crop for cabbage aphids near brassicas. Trap cropping is a documented principle but is not a tested brussels-nasturtium pairing, so treat it as a plausible aid rather than a proven control. Well-grounded
interplant nearby
Keep apart from
Other brassicas Keep brussels sprouts away from other cabbage-family plants like broccoli, cabbage, kale, and cauliflower. They share the same pests and diseases, so grouping them makes problems worse.Planting brussels sprouts shoulder to shoulder with their brassica relatives, broccoli, cabbage, cauliflower, kale, collards, concentrates the family's shared pests (cabbage aphids, cabbageworms, loopers, harlequin bugs, root maggots) and shared diseases in one spot, and repeated same-family planting lets soil-borne clubroot build up. Spread brassicas out and rotate where they grow each year. Well-grounded
Strawberries A traditional caution that brassicas and strawberries inhibit each other. There is no documented mechanism or T1 support; it persists as folklore. Traditional
Provenance tagged inline · see methodology for the labeling system Key
Harvest signals

When to pick

Start picking at the bottom of the stalk when the lowest sprouts are firm and about 1 inch across, like tiny cabbages, and still tight and green. Twist them off and pull the leaf under them, then work up the stalk over the following weeks. They taste sweetest after a frost.Pick sprouts from the bottom of the stalk upward once they are firm, tight, and about 1 to 1.5 inches across, deep green, before they loosen or yellow. Snap or twist off the lowest mature sprouts and strip the leaf below each as you go; the upper sprouts keep sizing up for weeks. Flavor is best after a frost or two.

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Yield

What to expect

Each plant gives you a stalk of about 50 to 100 sprouts, picked a few at a time over several weeks, often a pound or two per plant. How much you get depends on the variety and how long and cool your season is.A single stalk yields roughly 50 to 100 sprouts, about 0.75 to 2 pounds per plant, harvested progressively up the stalk over several weeks rather than all at once. Extension row yields run about 4 to 10 pounds per 10 feet of row depending on variety and season length.

The sprouts ripen up the stalk over several weeks, with the best picking in cool late fall and, in mild areas, winter. They do poorly in heat and stop once a hard freeze or spring warmth ends the plant.Sprouts mature from the bottom up over weeks, peaking in the cool weather of late fall and, in mild zones, winter. Production stalls or fails in heat (loose sprouts), and ends when a deep freeze below about 20°F damages the plant or when warmth in spring makes overwintered plants bolt. Here is the trick: brussels sprouts need cool weather to form good sprouts, so plant them to mature in fall, not summer. Then pick from the bottom up as the sprouts firm, a few at a time, instead of waiting for the whole plant. Be patient, the best sprouts come after frost.The two keys to a good crop are timing and patience: time the plant to reach sprout formation in cool weather (heat gives loose, bitter sprouts), and then harvest progressively from the bottom rather than waiting for the whole stalk. New growers often plant too late, pick too early (before the sprouts firm up and a frost sweetens them), or give up on a plant that simply has not reached cool weather yet.

What changes yield
Timing and temperature: sprouts form firm and sweet only in cool weather; reaching sprout formation in heat gives loose, bitter, leafy sprouts or none at all.Season length: brussels sprouts need roughly 90 to 180 days, so a short season or a late planting limits how far up the stalk the crop ripens before deep cold.Nitrogen and even moisture: steady feeding builds the stalk, but excess nitrogen late and drought stress both loosen the sprouts.Topping and lower-leaf removal: topping the plant and stripping lower leaves even up and hasten the sprouts, raising usable yield in a short season.Variety: early types finish in short seasons; late heavy-yielders need a long cool window; red types are slower and less productive.
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Pick your variety

Recommended varieties

Jade Cross and Long Island Improved are easy, dependable choices, and Long Island Improved lets you save seed. Diablo is a later, heavy producer for a long cool season. Hestia gives neat, even sprouts, and red types like Redarling are pretty but slower. If brassica diseases are a problem where you live, look for a disease-resistant variety such as Nautic.Match the variety to the season length. Where the season is short, lean on early types (Jade Cross, Long Island Improved) that finish before deep cold; where it is long and cool, late heavy-yielders like Diablo reward the wait. Hybrids (Jade Cross, Hestia, Nautic, Diablo) give more uniform sprouts and firmer standing than the open-pollinated Long Island Improved, which in turn is the one to grow for saving seed. Where brassica disease is chronic, choose a resistant hybrid such as Nautic. Red types are slower and more ornamental than productive.

Long Island Improved
A dependable open-pollinated heirloom (about 90 days) with good production, eating quality, and storage; compact and a longtime garden standard. Seed-saveable, unlike the hybrids.
Jade Cross / Jade Cross E
An early, productive AAS-winning hybrid (about 100 days) on a shorter, wind-firm plant; the 'E' strain carries some Botrytis resistance. A reliable first choice.
Diablo
A late, heavy-yielding hybrid (about 110 days) of high quality that holds well in cold; a strong pick for a full fall-into-winter harvest.
Hestia
A uniform, upright hybrid bred for tidy, even sprouts and good standing ability; widely grown for fall. Days to maturity approximate.
Nautic
A hybrid with a notably broad disease-resistance package (black rot, Fusarium yellows, powdery mildew, white rust per Cornell), useful where brassica disease is chronic. Days to maturity approximate.
Redarling / Ruby (red types)
Purple-red sprouts that hold their color when cooked; ornamental as well as edible. Red types tend to be later (about 140 days) and a touch less productive, so give them a long season.
Off the vine

Storing your harvest

Room temp
Don't leave brussels sprouts out on the counter; they soften and yellow fast. Refrigerate them soon after picking, and remember the plant keeps them best of all, holding the sprouts on the stalk in cold weather.Sprouts soften and yellow at room temperature within a day or two, so refrigerate promptly after picking. A key brussels advantage is that the plant itself is the best storage: sprouts hold firm on the standing stalk for weeks in cold weather, so harvest close to use.
Fridge
Store brussels sprouts unwashed in a perforated bag in the fridge's crisper drawer, where they stay good for about 3 to 5 weeks. Keep them away from apples and other ripening fruit, which make them go off sooner.Refrigerate unwashed in a perforated bag in the crisper; sprouts hold their quality for roughly 3 to 5 weeks, and up to several months near 32°F at high humidity. Keep them away from ethylene-producing fruit, which yellows them faster.
Freezer
Brussels sprouts freeze well if you blanch them first. Trim and wash them, boil 3 to 5 minutes, cool right away in ice water, drain, and freeze. They keep up to about a year.Brussels sprouts freeze well once blanched: trim and wash, blanch about 3 to 5 minutes depending on size, cool quickly in ice water, drain, and freeze. Blanching halts the enzymes that otherwise cause off-flavors and loss of color, and frozen sprouts keep up to about a year.
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When something goes wrong

Common problems

01 of 04
What happened Instead of tight little cabbages, your sprouts are loose, open, and leafy. This usually means the plant was forming sprouts in weather that was too warm, or it was growing too fast and soft from rich soil or extra nitrogen, or the ground was too loose. People often blame the variety, but timing and conditions are almost always the cause. Next time, plant so the sprouts form in cool fall weather, firm the soil before planting, and ease off nitrogen once sprouts start.Sprouts are loose and leafy rather than firm and tight. The usual drivers are heat during sprout formation, excess late nitrogen, loose or recently dug soil, and drought stress; brussels sprouts set tightly only in cool, settled conditions. Next time time the crop so sprout formation lands in cool fall or winter weather, plant into firm soil, taper nitrogen as sprouts set, and keep moisture even. Next season Aim for sprouts to form in cool weather, firm the soil before planting, and go easy on late nitrogen.Time sprout formation for cool weather, plant into firm soil, taper late nitrogen, and hold even moisture.
02 of 04
What happened Your plant grew into a big leafy stalk but never made sprouts, or only tiny ones. Brussels sprouts need a long, cool stretch to form sprouts, so this usually means they were planted too late, ran into heat, or got so much nitrogen that they kept making leaves. Next time, start them earlier so they have a long season, plan for the sprouts to form in cool fall weather, and ease off the nitrogen once the stalk is built.The plant built a tall vegetative stalk but set few or no sprouts. The causes are an insufficient cool window (planted too late, or heat persisted), or excess nitrogen keeping the plant vegetative. Brussels sprouts need roughly 90 to 180 days and cool weather to fill the stalk. Next time start 5 to 6 weeks ahead under cover, set out on time so sprout formation reaches cool weather, taper nitrogen after the frame is built, and consider topping to push the sprouts. Next season Start earlier for a long season, aim for cool-weather sprouting, and go easy on nitrogen later on.Lengthen the season with an earlier start, time sprouting for cool weather, taper nitrogen, and top to push sprout set.
03 of 04
What happened You found dense clusters of small gray-green insects tucked down inside the sprouts, hard to wash out. Cabbage aphids love brussels sprouts and hide right in the sprouts, and they breed fastest on soft growth from too much nitrogen on the long fall crop. People often miss them until harvest. Next time, scout the growing tips and leaf axils weekly, knock colonies off early, avoid overfeeding nitrogen, and welcome ladybugs and lacewings.Dense cabbage-aphid colonies lodged inside the sprouts, contaminating the harvested buds and very hard to clean. The waxy gray-green cabbage aphid specializes on brassicas, explodes on the long-season fall crop, and favors the soft growth excess nitrogen produces. Next time scout tips and axils weekly, dislodge colonies early with a water jet or insecticidal soap into the axils, taper nitrogen as sprouts set, and conserve natural enemies; once aphids are inside the sprouts they are nearly impossible to remove. Next season Scout weekly, knock off colonies early, go easy on nitrogen, and encourage beneficial insects.Scout weekly, dislodge colonies early into the axils, taper nitrogen, conserve beneficials, and act before aphids reach the sprouts.
04 of 04
What happened Your plants stayed small and yellowish, wilted in the afternoon, and when you dug one up the roots were swollen into lumps. That is clubroot, a soil disease that infects cabbage-family roots and lasts for years in the soil. It builds up when brassicas are grown in the same spot repeatedly and in acidic soil. Next time, rotate so cabbage-family crops do not return to that bed for several years, keep the soil pH near neutral, and improve drainage.Plants were stunted and chlorotic, wilted by day, and showed galled, clubbed roots, the signature of clubroot (Plasmodiophora brassicae). The soilborne organism persists for years and builds under repeated brassica cropping and acidic, poorly drained soil. Next time rotate cole crops out for at least 3 years (5 to 7 where clubroot is known), lime toward a neutral pH, and improve drainage; there is no in-season cure. Next season Rotate brassicas out of that bed for several years, keep soil pH near neutral, and improve drainage.Use a long brassica rotation, raise pH toward neutral, improve drainage, and remove and destroy infected plants.
The usual suspects

Pests & diseases

Pests
Cabbage aphids
P · 01
Symptoms You'll see clusters of small gray-green insects with a dusty, waxy coating on the new growth and, worst of all, packed down inside the developing sprouts where they are very hard to wash out. Leaves may curl and there can be a sticky film.The gray-green, waxy-coated cabbage aphid is the signature brussels sprouts pest. Colonies build on growing tips and leaf undersides and then lodge deep inside the developing sprouts, where they contaminate the marketable buds with insects and honeydew and are extremely hard to clean at harvest. Populations explode on the long-season late-summer and fall crop. Cause Cabbage aphids are tiny insects that suck the plant's juices and breed fast, especially on the long-season fall crop. They love brussels sprouts and hide right inside the little sprouts, which is the part you eat.Brevicoryne brassicae, a brassica-specialist aphid, sucks sap and reproduces rapidly; on brussels sprouts it feeds in the upper leaves, flower buds, and especially within the forming sprouts. Contamination of the harvested sprouts with aphids and sticky honeydew is usually the real problem rather than plant stunting. Organic treatment Knock colonies off with a strong spray of water and hit the undersides of leaves and into the sprouts with insecticidal soap or neem oil, repeating every few days. Welcome ladybugs and lacewings, which eat aphids.Dislodge colonies with a strong jet of water and spray insecticidal soap, neem, or horticultural oil with thorough coverage of leaf undersides and into the sprouts; repeat every few days. Conserve natural enemies (the parasitoid Diaeretiella rapae, hoverflies, ladybugs) that suppress this aphid. Prevention Check the growing tips and sprouts often and act early, before the aphids get down into the sprouts. Go easy on nitrogen fertilizer once sprouts form, since soft growth draws them, and clear away old cabbage-family plants after harvest.Scout growing tips and the leaf axils weekly and catch infestations before aphids colonize the sprouts. Avoid excess nitrogen once sprouts set (soft growth favors them), use reflective mulch or row cover on young plants, and destroy crop debris that carries them over.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Balanced nitrogen feeding

    Ease off the nitrogen fertilizer once sprouts start forming along the stem. Heavy feeding pushes out soft new growth, and that soft growth is what draws these aphids.Hold nitrogen back from the point sprouts set. The succulent tissue it produces is what this brassica specialist builds on, and pressure already runs heaviest on the long-season late-summer and fall crop.

  2. Garden sanitation

    When a cabbage-family planting is finished, pull it out instead of letting it stand. Aphids carry over on that leftover growth and move onto whatever you plant next.Destroy brassica crop debris rather than leaving it in the bed; it is one of the things that carries this aphid across the gap between plantings.

  3. Reflective mulch

    A reflective mulch, a light-colored or foil-faced sheet laid on the soil, makes it harder for flying aphids to settle on young plants. It goes down while the plants are still small, which is the stage it is meant for.Reflective mulch under young plants is one of the two coverings this crop's guidance names against the aphid. It belongs to the small-plant stage, laid before colonies establish rather than in answer to them.

  4. Floating row cover

    A row cover, a light fabric sheet that lets light and water through while keeping insects off, stops winged aphids landing on young plants. Keep checking the growing tips and the folds where leaves meet the stem even so, because catching a colony early is what keeps it out of the sprouts.Cover young plants to block the winged colonizers, and scout the growing tips and leaf axils weekly regardless. The aim throughout is finding a colony before it lodges inside the developing sprouts, where the insects and their sticky honeydew contaminate the buds you harvest and are extremely hard to clean out.

  5. Water spray

    Knock the clusters off with a strong jet of water from the hose, working the undersides of the leaves and down into the sprouts. Repeat every few days while you are still finding them, and spray early enough in the day that the leaves dry.A forceful jet dislodges colonies physically and leaves the natural enemies untouched. Direct it at leaf undersides and into the forming sprouts, and repeat at intervals of a few days rather than treating it as one pass.

  6. Beneficial predators

    Ladybugs and lacewings eat aphids, so make them welcome and skip broad sprays that would take them out along with the pests.Conserve the natural enemies that suppress this aphid, among them the parasitoid wasp Diaeretiella rapae, hoverflies and lady beetles. A broad-spectrum material removes them and leaves a fast-reproducing pest a clear field.

  7. Insecticidal soap

    Spray insecticidal soap right onto the aphids, coating the undersides of the leaves and getting it down into the sprouts, then repeat every few days. It acts only where it wets them, so soak the clusters instead of misting the whole plant.Soap is a contact material, so coverage of the leaf undersides and the interior of the forming sprouts decides the outcome, and the waxy bloom on these colonies is part of why deliberate, repeated application is needed. Spray only where the aphids are, since it also kills the soft-bodied beneficials it wets.

  8. Neem oil

    Neem oil is a second choice for the same soaking job. Work it into the same hidden places, repeat every few days, and hold off in high heat or when the plants are dry at the roots.Neem is the coverage-dependent alternative to soap here, and it spares beneficials once it has dried. Keep it off anything in flower, weeds included, where bees forage, and off water-stressed plants in hot weather.

  9. Horticultural oil

    Horticultural oil, a light spray oil, is a third contact option that coats the aphids it reaches. Cover the same leaf undersides and sprouts, and avoid using it on hot days or on thirsty plants.Horticultural oil rounds out the contact choices alongside soap and neem. Whichever you reach for, thoroughness of coverage matters more than the product does, and none of the three should go on a water-stressed planting in high heat.

The bottom rungs are products with label rules: timing, pollinators, and days to wait before harvest. Before you spray →

Cabbageworms and cabbage loopers
P · 02
Symptoms You'll see ragged holes chewed in the leaves, green caterpillars on the plant, and dark droppings, and later the caterpillars may bore into the sprouts. Some loop up in the middle as they crawl.Ragged holes chewed in the leaves with green caterpillars and dark frass; as the season goes on, larvae also bore into the sprouts and foul them. Imported cabbageworms are velvety green; cabbage loopers move in a looping arch; diamondback larvae are small and wriggle when disturbed; the cross-striped cabbageworm shows black and white bands. Cause These are caterpillars that hatch from eggs laid by white butterflies and small moths. They love cabbage-family plants and chew the leaves, and they can tunnel into the sprouts you want to eat.The larvae of the imported cabbageworm, cabbage looper, and diamondback moth (Clemson rates the diamondback the most numerous in home gardens) feed on brassica foliage and contaminate the sprouts; the adults are white or brownish butterflies and moths that lay eggs on the leaves. Organic treatment Spray Bt, which is low in toxicity to people, pets and bees and acts on caterpillars rather than on insects in general, or spinosad. Bt cannot tell a pest caterpillar from a butterfly one, so treat only the plants that have a problem. Pick caterpillars and eggs off by hand from under the leaves. Spray again after rain, since it washes off.Spray Bt (Bacillus thuringiensis kurstaki) or spinosad, which target caterpillars and spare beneficials, and hand-pick larvae and eggs from leaf undersides. Repeat after rain, since Bt breaks down. Prevention Cover plants with a light fabric row cover after planting to keep the butterflies and moths from laying eggs, clear away old cabbage-family plants, and watch for the first white butterflies as your signal to act.Use floating row cover or fine mesh from transplanting to exclude the egg-laying adults, clean up brassica debris that shelters pupae, and scout for the first white butterflies as a spray cue. Tighten control once sprouts begin forming, since damage to the buds is the costly kind.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Garden sanitation

    Clear away old cabbage-family plants when a crop is done. The caterpillars pass a resting stage, called the pupa, in that leftover debris, so hauling it off leaves fewer butterflies and moths for the next round.Removing spent brassica material takes away the debris that shelters pupae between crops, trimming the local carryover of the imported cabbageworm, looper and diamondback complex.

  2. Floating row cover

    Put a row cover, a light fabric sheet that lets light and water in while keeping insects out, over the plants after planting. The white butterflies and small moths cannot lay eggs on leaves they cannot reach.Floating row cover or fine mesh from transplanting excludes the egg-laying adults of the whole complex at once. Because the point is exclusion, the cover belongs on the crop before the first white butterflies appear; sighting them is a spray cue, not a cue to start covering.

  3. Handpicking

    Turn the lower leaves over and take off the caterpillars and the eggs you find there. On a few plants this does real work, and it matters more as the sprouts start to form, since a caterpillar that tunnels into a sprout has spoiled the part you were growing it for.Hand removal of larvae and eggs from leaf undersides is practical at garden scale, and the species sort out in hand: velvety green imported cabbageworms, loopers that arch as they crawl, small diamondback larvae that wriggle when disturbed, and the black-and-white banded cross-striped cabbageworm. Weight the passes toward the period when sprouts are forming, since damage to the buds is the costly kind.

  4. Bacillus thuringiensis (Bt)

    Bt, short for Bacillus thuringiensis, is a spray that acts on caterpillars and is low in toxicity to people, pets and bees. It cannot tell a pest caterpillar from a butterfly one, so treat only the plants that have a problem and keep it off plants you are growing for butterflies. Rain washes it off, so a shower means going out again.Bt kurstaki acts on the larvae and spares beneficials, and the first white butterflies on the wing are the cue to begin. It breaks down, so reapply after rain, and confine applications to infested plantings, since it takes caterpillars as a group, desirable species included.

  5. Spinosad

    If Bt and hand-picking are not keeping up, spinosad is the stronger organic caterpillar spray. Hold it for genuine pressure, put it on toward dusk while bees are off the flowers, and follow the label.Spinosad is the escalation once the softer rungs have not held, and control is worth tightening as sprouts form, when larvae bore into the buds. It is toxic to bees while wet and for roughly a day afterward, so time applications to dusk and keep them off flowering plants.

The bottom rungs are products with label rules: timing, pollinators, and days to wait before harvest. Before you spray →

Harlequin bug
P · 03
Symptoms Shield-shaped black-and-orange (or black-and-red) bugs on the leaves, which develop white or yellow spots, then brown and look tattered. It is mostly a warm-region problem and loves cabbage-family plants.Shield-shaped bugs up to about 3/8 inch, brightly black-and-yellow or black-and-red, feeding with piercing-sucking mouthparts that leave white stipples; affected leaves brown and look tattered, and heavy feeding wilts and deforms plants. A warm-region brassica specialist. Cause The harlequin bug is a colorful stink-bug relative that pierces the leaves and sucks the juices, leaving pale blotches. It strongly prefers cabbage-family plants, especially in the South.The harlequin bug (Murgantia histrionica) is a true bug that specializes on cole crops, most damaging in the southern United States, where it completes two to three generations a year and overwinters as an adult in debris and weeds. Organic treatment Search out and crush the bugs, their barrel-shaped eggs laid in rows, and the young ones by hand. Use a row cover to keep them off, pull badly infested plants, and clear away weeds and old plants where they hide over winter.Hand-pick and crush adults, nymphs, and the barrel-shaped egg rows; exclude with floating row cover; remove heavily infested plants. Insecticidal soap, pyrethrum, or neem help where pressure is severe. Prevention Clean up garden debris and cabbage-family weeds where the adults overwinter, use row cover, and consider a trap crop of cleome or mustard to lure them away from the main crop, then destroy it.Eliminate overwintering sites by removing crop debris and crucifer weeds, use row cover, and deploy an early trap crop of cleome or mustard to divert overwintering adults, then destroy it before the main crop is set out.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Garden sanitation

    Clear garden debris, spent cabbage-family plants and cabbage-family weeds at the end of the season, since that is the cover the adults spend the winter in. If a plant is overrun in season, take the whole thing out instead of fighting for it.The species passes the winter as an adult in debris and crucifer weeds, so taking out both is the main preventive lever against an insect that completes two to three generations a year in the southern states. Roguing heavily infested plants belongs to the same pass.

  2. Trap cropping

    Put in a small patch of cleome or mustard before the sprouts are set out, so the overwintered bugs gather there rather than on the transplants. That patch is grown to be given up, not picked: this crop's guidance says to destroy it before the main planting goes in. Check this method's cautions for how late it can be left.An early cleome or mustard stand aggregates overwintered adults away from the transplants, and this crop's guidance carries the tactic through to its end, destroying the stand before the main crop is set out. That matters more here than on a quick brassica: sprouts hold the bed into late fall, so a loaded patch left standing sits beside a planting with months still to run. The removal deadline is in this method's cautions.

  3. Floating row cover

    A row cover, a light fabric sheet laid over the plants, keeps the bugs off. Get it on early, before you are seeing them.Exclusion keeps the adults from reaching the crop at all, which is worth most at the front of the season, while the generation that overwintered is still searching out cabbage-family hosts.

  4. Handpicking

    Walk the plants and crush the bugs, the young ones, and the barrel-shaped eggs laid in neat rows. They are shield-shaped and brightly marked, so they are not hard to find.Destroying adults, nymphs and the barrel-shaped egg rows by hand suits garden scale, since nothing about this insect is inconspicuous: a shield-shaped true bug up to about 3/8 inch, patterned black with yellow or red.

  5. Insecticidal soap

    Where the bugs get severe, insecticidal soap sprayed straight at them can help. Only the bugs it actually wets are affected, so put the nozzle on them and not over the foliage in general.Soap is listed as help where pressure is severe, no more than that. It is strictly contact-acting, so direct it onto the insects and their clusters, and spray only where they are, since it also kills the soft-bodied beneficials it wets.

  6. Neem oil

    Neem oil is another spray named for severe pressure. Coat the bugs directly, and skip it in high heat or on plants that are dry at the roots.Neem is the alternative contact option under severe pressure, so coverage of the insects themselves decides the result. Keep it off anything in flower nearby, weeds included, where bees are foraging.

  7. Pyrethrin (botanical)

    Pyrethrum, the botanical spray pressed from chrysanthemum flowers, is also listed for severe pressure and knocks the bugs down on contact. It leaves little behind, so expect to repeat it, and keep it away from anything in flower: it sits in UC IPM's strictest bee band, which grants no evening window.Pyrethrin supplies contact knockdown where pressure is severe and persists little, so repeat applications are likely. Being organically acceptable does not soften the bee precaution, which is the strictest band with no dusk exception, and it is rated moderate for harm to natural enemies, so a spray can remove the predators that were holding something else down.

The bottom rungs are products with label rules: timing, pollinators, and days to wait before harvest. Before you spray →

Flea beetles
P · 04
Symptoms Lots of tiny round holes in the leaves of young plants, made by small dark beetles that jump away like fleas when you get close. Bad damage can stunt seedlings.Tiny round shot-hole pits chewed in the leaves of young plants; the small dark beetles jump like fleas when disturbed. Heavy feeding stunts or kills seedlings and slows establishment of the long-season crop. Cause Flea beetles are small jumping beetles that chew on young cabbage-family leaves. They hurt seedlings most, because a tiny plant can't grow fast enough to recover.Flea beetles chew the foliage of young brassicas and are most damaging at the seedling stage; a vigorous transplant generally outgrows them, but a stalled seedling can be set back badly. Organic treatment Cover young plants with a row cover, and if there are a lot of beetles, use a spray such as spinosad. The main goal is to get the seedlings big enough to handle the damage.Protect seedlings with row cover and spray spinosad if pressure is high; the goal is getting plants past the vulnerable seedling stage. Prevention Cover seedlings with row cover from the start, keep them strong with steady water and food so they grow past the damage, and pull nearby weeds in the cabbage family.Use row cover from transplanting, keep seedlings vigorous with even water and feeding so they grow through the damage, and clean up weedy brassica relatives nearby.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Clearing the weeds that host it

    Pull out the cabbage-family weeds that come up around the bed. They feed the same beetles, so clearing them leaves fewer waiting to move onto your seedlings.Nearby crucifer weeds host the same beetles, so a bed and its margins kept clear of them leave the population nothing to hold on to while it waits for a young planting.

  2. Floating row cover

    Cover young plants with a row cover, a light fabric sheet that lets light and water through but keeps insects out, right from planting. Steady water and feeding belong with it, because the real goal is getting the seedlings big enough to shrug off the little shot holes.Exclusion from transplanting protects the stage that is actually at risk. A vigorous transplant generally grows through the feeding while a stalled seedling can be set back badly, which is why even watering and feeding sit alongside the cover rather than after it, and why a slow start matters on a crop that needs the whole season.

  3. Spinosad

    If there are a lot of beetles anyway, a spinosad spray can knock them back while the seedlings get established. Spray toward dusk, when bees are not foraging, and follow the label.Spinosad supplements exclusion where pressure is high, and the objective does not change: carry the stand past the vulnerable seedling stage rather than run a spray program across a crop that will stand for months. Time applications to dusk, since it is toxic to bees while wet and about a day after.

The bottom rungs are products with label rules: timing, pollinators, and days to wait before harvest. Before you spray →

Cabbage root maggot
P · 05
Symptoms New transplants wilt and grow badly or fall over. If you pull one up, you'll find small white maggots eating the roots. It is worst in cool, wet soil.Transplants wilt, grow poorly, and may collapse; pulling a plant reveals small white maggots tunneling in the roots and lower stem. Damage is worst in cool, wet soil at establishment. Cause A small fly lays eggs at the base of the plant, and the maggots that hatch burrow down and eat the roots. The fly is most active in cool, damp weather.The larvae of the cabbage root fly tunnel into brassica roots; the adult lays eggs at the stem base, and the maggots feed below, sometimes killing young plants. Organic treatment Once the maggots are in the roots you can't save that plant, so pull and throw away the badly damaged ones. Put your effort into protecting the rest from new eggs.There is no effective rescue once maggots are in the roots; remove and destroy badly affected plants and protect the rest from further egg-laying. Prevention Put a small collar or disk around the base of each transplant to stop the fly from laying eggs there, or use a row cover. Avoid planting into cold, soggy soil, and rotate away from where cabbage-family plants grew.Place a collar or disk around the stem base at transplanting to block egg-laying, or use row cover; avoid planting into cold, wet soil and rotate away from where brassicas grew.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Crop rotation

    Plant where cabbage-family crops have not grown recently. The fly builds up in ground that carried its host plants, so moving the bed puts new transplants away from it.Rotating off recent brassica ground separates the new transplants from the population carried over where the previous crop stood, and it is settled before anything goes in.

  2. Garden sanitation

    Once maggots are in the roots that plant cannot be saved, so pull the badly damaged ones and get them out of the garden. Put the work into stopping the fly from laying again around the plants that are still sound.There is no rescue once larvae are tunneling in the roots and lower stem, so rogue out the wilting and collapsing plants and redirect the work to blocking further egg-laying on the survivors.

  3. Floating row cover

    A row cover, a light fabric sheet spread over the bed, means the fly never reaches the stem bases where it would lay. It earns the most at establishment, when the soil is cool and damp and the damage is worst. Choose a bed that has been out of cabbage-family crops for a season, since fabric over old brassica ground shuts the emerging flies in with the sprouts.Exclusion through cool, wet establishment covers the stretch of heaviest adult activity and protects the stage root feeding can kill outright, the new transplant. Lay it over ground that did not carry brassicas last season, so the cover is not holding emerging flies in with the crop.

  4. Stem collars

    Fit a small collar or disk around each transplant, sitting flat on the soil. It denies the fly the spot it lays in, right against the stem, which is where the maggots start down toward the roots.A basal collar or disk fitted at transplanting takes away the egg-laying site at the stem base. It is the per-plant option where covering a whole bed of a long-season crop for the establishment period is impractical.

No spray for this one. Prevention is the control.

Diseases
Clubroot
D · 01
Symptoms Plants wilt in the afternoon, stay small and yellowish, and don't bounce back. If you dig one up, the roots are swollen into lumpy, club-shaped knobs.Plants wilt in the heat of the day, grow stunted and yellowed, and recover poorly; roots are swollen into distorted clubs and galls instead of normal fine roots. Cause A germ that lives in the soil infects the roots of cabbage-family plants and makes them swell, which stops the plant from taking up water and food. It stays in the soil for years.A soilborne organism (Plasmodiophora brassicae) infects brassica roots and forms the galls, which block water and nutrient uptake. It persists in soil for many years, spreads in contaminated soil and water, and infects most readily in acidic soils below pH 6.5. Organic treatment There's no cure once a plant has it, so pull and destroy infected plants. Keeping the soil from being too acidic (closer to neutral) helps hold it back, and growing cabbage-family plants only rarely in that spot starves the germ out.There is no cure once plants are infected; remove and destroy them. Raising soil pH toward neutral with lime suppresses the disease, and long rotations starve it out over time. Prevention Don't grow brussels sprouts or other cabbage-family plants in the same spot more than once every few years, longer if you've had clubroot. Keep the soil from being too acidic, improve drainage, and clean soil off your tools.Rotate brassicas out of affected ground on a long cycle (UMN advises 5 to 7 years where clubroot is known), keep soil pH up, improve drainage, and avoid moving infested soil on tools and boots.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Crop rotation

    Once clubroot turns up, keep brussels sprouts and their cabbage-family relatives out of that bed for several years, longer if it has been bad. The organism lives on in the soil and slowly starves when there is nothing there for it to infect.The pathogen persists in soil for many years; where clubroot is known, UMN advises rotating brassicas out on a 5 to 7 year cycle, which draws the soil population down over time. On a crop that holds its ground most of the season, that is a bed-planning decision rather than an in-season one.

  2. Raise soil pH (liming)

    Lime the bed so the soil is not sitting on the acid side, closer to neutral. That holds the disease back rather than curing it, and it is worth keeping the liming to the affected bed, since most vegetables prefer soil a little more acid than that.Infection proceeds most readily in acidic soil, below about pH 6.5, so liming toward neutral suppresses it. Pair it with the long rotation, since neither clears established ground on its own, and confine the treatment to affected ground.

  3. Improve drainage

    Fix the places where water stands in the bed. The disease travels in soil and water, so drainage takes away part of what it needs.Water moving through the bed is one of the ways this organism gets around, so ground that drains rather than staying saturated gives it less to work with. On heavy or low-lying beds the correction is worth making before a susceptible crop goes in.

  4. Garden sanitation

    There is no cure once a plant has it, so lift it with the clubbed roots attached and get it out of the garden. Knock the soil off your tools afterward, because the disease rides along on dirt carried out of an infested bed.Nothing applied to an infected plant will help, so lift it whole, galls and all, and destroy it. Then deal with the carrier: soil clinging to tools and boots is how an infested bed seeds a clean one.

No spray for this one. Prevention is the control.

Black rot
D · 02
Symptoms Yellow patches shaped like the letter V appear at the leaf edges, pointing inward, with black veins inside them. It can spread through the plant and rot the leaves and sprouts.Yellow, V-shaped lesions spread inward from the leaf margins, with the veins inside the V turning black; the disease moves through the vascular system and can blacken and rot foliage and sprouts. Cause A bacteria that often comes in on infected seeds or transplants. It gets into the leaves and travels through the plant's veins, spreading fastest in warm, wet weather.A seedborne bacterium (Xanthomonas campestris pv. campestris) that enters through leaf pores and wounds and moves through the veins; it spreads in warm, wet conditions and on infected seed or transplants. Organic treatment There's no real cure, so remove and destroy infected plants to keep it from spreading. Don't handle or brush against the plants while they're wet, because that spreads the bacteria.There is no effective cure; remove and destroy infected plants. Avoid working among plants when foliage is wet, since that moves the bacteria. Prevention Begin with clean, certified seed and healthy transplants, don't plant where cabbage-family crops grew recently, space plants for good airflow, and avoid overhead watering.Start with clean, certified seed and healthy transplants (a hot-water seed treatment helps), rotate 2 to 3 years away from brassicas, give plants room for airflow, and avoid overhead watering and handling wet foliage.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Clean planting stock

    Begin with certified seed and transplants that look healthy. This one usually arrives on the seed or on the young plants themselves, so what you plant with is most of the defense.The bacterium is seedborne, so certified seed and transplants you know are clean shut the main entry route, and a hot-water seed treatment adds a margin where black rot has appeared before. The decision is settled at purchase, before anything reaches the bed.

  2. Crop rotation

    Keep the planting off ground that carried cabbage-family crops recently. Two to three years should pass before brassicas return to that spot.Rotate 2 to 3 years off brassicas, so what survives locally between crops is spent before a susceptible planting returns to that ground.

  3. Airflow and spacing

    Set the plants far enough apart that air passes between them and the foliage dries. The disease runs fastest in warm, wet weather, so drying time works against it.Open spacing shortens the warm, wet leaf conditions the bacterium spreads fastest in. Brussels sprouts carry a wide canopy for months, so the room has to be given at planting; it cannot be added later.

  4. Water at the base

    Put the water on the soil rather than over the tops of the plants; watering from above splashes the bacteria from one leaf to the next.Skip overhead irrigation, which wets foliage and splashes the bacterium between plants. It enters through leaf pores and wounds, so free water sitting on the leaf is what it is waiting for.

  5. Staying out of wet foliage

    Stay out of the planting while the leaves are wet. Brushing past wet plants carries the bacteria from a sick one onto a healthy one.Work the bed only when foliage is dry. Handling wet plants moves the bacterium efficiently, and the rule holds after rain and dew, not only after watering. What it buys is a slower rate of spread, not an end to an infection already moving.

  6. Garden sanitation

    Nothing will cure an infected plant, so lift it and carry it out of the garden before the disease works its way to the ones beside it. The tell is a yellow V-shaped patch at the leaf edge pointing inward, with blackened veins inside it.With no effective cure, roguing symptomatic plants is the in-season control. The V-shaped marginal lesions with blackened veins allow an early call, before the pathogen has run through the vascular system and blackened foliage and sprouts.

No spray for this one. Prevention is the control.

Alternaria leaf spot
D · 03
Symptoms Small dark spots on the leaves that grow into round patches with rings inside them, like a tiny target. Bad cases yellow the leaves and can spot the sprouts.Dark lesions enlarge into circular spots with characteristic concentric rings (a target-spot look) and a yellow halo; severe spotting downgrades the leaves and can blemish the sprouts. Favored by warm, wet conditions. Cause A fungus that spreads in warm, wet weather and infects the leaves, leaving target-like spots. It is worse on crowded, damp plantings and can come in on infected seed.Fungi in the genus Alternaria (chiefly A. brassicicola) infect brassica foliage, spreading by spores in wind and splashing water; infected seed, crop debris, and long leaf wetness drive it. Organic treatment Remove and destroy badly spotted leaves, improve airflow so leaves dry quickly, and use a copper spray if it spreads. Avoid wetting the leaves when you water.Remove and destroy spotted leaves and debris, improve airflow, avoid overhead watering, and apply a copper-based fungicide if pressure is high. Prevention Start with clean seed, rotate away from brassicas, space plants for airflow, water at the soil line, and clear away old plant debris.Use clean, disease-free seed (a hot-water treatment helps), rotate about 3 years away from brassicas, space for airflow, water at the soil line, and clear crop debris that harbors spores.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Clean planting stock

    Start with clean seed. The fungus can ride in on the seed, so a clean packet keeps it from turning up with the crop.Alternaria is seedborne, so disease-free seed, hot-water treated where the disease has a history, closes one of the two ways it enters a garden. Crop debris is the other.

  2. Crop rotation

    Move brussels sprouts and their cabbage-family relatives to a different spot, about three years away from ground that grew brassicas, since the fungus carries over there.Rotate roughly 3 years off brassicas. The fungi survive on crop debris between seasons, so the interval has to outlast the residue rather than just the season.

  3. Airflow and spacing

    Leave the plants enough room for air to pass through and dry the foliage quickly. Wet leaves are what the spots need to start, so time spent drying does much of the work for you.Long leaf wetness is what drives infection, so spacing that shortens wet periods works directly against target-spot lesions establishing and running together. On a plant that will stand into fall, that spacing is set once, at planting.

  4. Water at the base

    Keep the water at the soil line and off the foliage. The spores move in splashing water and need wet foliage to get started.Spores travel in wind and splashing water, so basal irrigation removes the splash route and keeps the watering itself from extending the wet period the fungus needs.

  5. Garden sanitation

    Pick off the badly spotted leaves as you notice them and clear plant debris out of the bed, since that is where the fungus waits for the next crop.Remove heavily spotted foliage during the season and clear crop debris afterward; residue is the principal carryover reservoir, and severe spotting can blemish the sprouts as well as downgrade the leaves.

  6. Copper fungicide

    If the spotting keeps spreading, a copper spray can help. It does more applied early than once the leaves are covered, keep it out of ponds and drains because copper is very harmful to fish and other water life, and follow the label rate.Copper is the escalation where pressure stays high. It protects new growth rather than curing spotted leaves, so it goes on early or not at all; it is highly toxic to aquatic life and accumulates at the soil surface with repeat use, so mind runoff and limit how often you lean on it. Which copper compound is on the label changes the acute hazard band, so read the active ingredient rather than the brand name.

The bottom rungs are products with label rules: timing, pollinators, and days to wait before harvest. Before you spray →

Downy mildew
D · 04
Symptoms Pale yellow blotches on top of the leaves, with fuzzy grayish growth on the underside, mostly in cool, damp weather. Bad cases discolor the leaves and can spot the sprouts.Pale yellow patches form on the upper leaf surface with a fuzzy gray growth underneath, mainly in cool, damp weather; severe infection discolors leaves and can blemish the sprouts. Brussels sprouts' cool, humid season overlaps the weather it likes. Cause A mold-like disease that loves cool, wet, humid weather and spreads through the air and water. Wet leaves and crowded plants make it worse.A fungus-like organism (Hyaloperonospora brassicae) that thrives in cool, wet, humid conditions and spreads by spores in water and air; long leaf wetness and crowded plantings favor it. Organic treatment Open up the airflow so leaves can dry, remove the worst leaves, and use a copper spray if it's spreading. It's hard to stop once the weather stays damp.Improve airflow and let foliage dry, remove badly affected leaves, and apply a copper-based fungicide if pressure is high; the disease is hard to stop once humidity stays high. Prevention Space plants so air moves between them, water at the soil instead of from above, and pick resistant varieties if downy mildew is common where you live.Space plants for good air movement, water at the soil line rather than overhead, and choose resistant varieties where downy mildew is common.
The control ladder

The ladder troubleshoots from the gentlest solution to the strongest. Start with the gentlest option and only move on when and if it doesn't work.

  1. Airflow and spacing

    Stand the plants far enough apart that moving air can dry the leaves. This disease wants cool, damp foliage, and that is the weather brussels sprouts finish in.Air moving through the planting is what shortens the wet periods this organism needs. Sprouts mature into cool, humid weather that suits it, so how far apart the plants stand is carrying more of the load here than it would on a summer crop.

  2. Water at the base

    Aim the water at the soil, not down over the foliage. It travels in splashing water and on leaves that stay wet.Putting water on the ground rather than into the canopy removes one of the things this organism travels in, and it keeps you from adding to a leaf wetness period the weather is already supplying.

  3. Resistant varieties

    Where downy mildew turns up most years, choose a variety listed as resistant at seed-buying time.Where downy mildew recurs regionally, the resistant cultivar is the seed-time choice that lowers the pressure everything else has to carry, and it counts for more on a crop standing in the ground for months than on a quick one.

  4. Garden sanitation

    Take off the worst leaves, the ones with pale yellow blotches on top and fuzzy gray growth underneath, so there is less disease to spread. Once the damp weather sets in this one is hard to check, which is why the steps above it carry most of the load.Pulling the badly affected foliage lowers the spore load, but the disease is difficult to arrest once humidity stays high, so removal supplements the preventive steps rather than replacing them.

  5. Copper fungicide

    Where it goes on spreading despite the rest, a copper spray can give some help. It does the most applied early rather than once the disease is everywhere, and keep it away from ponds and drains, since copper is very harmful to fish and other water life.Copper is where you go when the cultural steps are not holding and pressure stays high. It acts preventively, so it belongs at the first sign rather than partway into an established outbreak; keep spray and runoff away from water, and limit repeat reliance, since copper builds up in surface soil.

The bottom rungs are products with label rules: timing, pollinators, and days to wait before harvest. Before you spray →

Verified · 5 sources View
Seasoned
Where to plant next year

Crop rotation

Don't plant brussels sprouts or other cabbage-family crops in the same spot year after year. Waiting at least 3 years between them, and longer if you have had clubroot, helps avoid soil diseases.Rotate so brussels sprouts and their brassica relatives do not return to the same ground for at least 3 years, and longer where clubroot is present; the University of Minnesota advises against growing cole crops where they grew in the past four years, and clubroot warrants a 5-to-7-year break. Holding soil pH near neutral also helps suppress clubroot.

Family
Brassica family (Brassicaceae), the cole crops
Years between
3 years
in the same bed
Avoid following
Other cabbage-family crops like broccoli, cabbage, cauliflower, kale, and turnips.Other brassicas (broccoli, cabbage, cauliflower, kale, collards, kohlrabi, turnip, radish, mustard), which share clubroot and the cabbage-family pests.
Plant after
Legumes such as beans and peas, or unrelated crops like tomatoes, squash, or onions.
Verified · 2 sources View
In the app · pre-launch

When plant taps you on the shoulder

The plant app sends a timely reminder at every critical moment of your brussels sprouts season. The wording adjusts to whichever you pick: beginner or seasoned. Here are three you'll see in Zone 9.

p
plant
You can top your brussels sprouts now Time to top the plant (optional)
Once the bottom sprouts are about an inch across, you can snip off the very top of the plant. This pushes the rest of the sprouts to grow bigger and more evenly. It is optional, but many gardeners do it. If you want to even up and hasten the upper sprouts, cut out the growing point at the top of the stalk now that the lowest sprouts are about an inch across. Top less than 60 days before your intended harvest, and ease off heavy nitrogen so sprouts stay firm.
p
plant
Time to start picking brussels sprouts Start picking from the bottom up
Your lowest sprouts should be firm and about an inch across. Twist them off starting at the bottom of the stalk and work your way up over the next few weeks. They taste sweeter after a frost. The lowest sprouts should be firm and about 1 to 1.5 inches across. Snap or twist them off from the bottom of the stalk upward, taking the leaf below each, and leave the upper sprouts to keep sizing up. They are sweetest after a frost.
p
plant
Frost ahead, your sprouts will sweeten Frost is coming: expect sweeter sprouts
Frost is coming, but that is good for brussels sprouts: the cold makes them sweeter. The plants handle frost fine down to about 20°F, so keep picking. In very cold areas, cut the whole stalk before a hard freeze. A frost is on the way, which is good news: brussels sprouts take frost in stride and the cold actually sweetens them. Mature plants hold while temperatures stay above about 20°F, so keep harvesting; in the coldest spots, cut whole stalks before a hard freeze.
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How we built this guide

Methodology & sources

Every date, temperature, spacing, and recommendation on this page is sourced from university cooperative extension publications, peer-reviewed agricultural research, NOAA climate data, and direct extension calendars. Where claims are softer (traditional gardening wisdom not formally documented), we say so.

Research-backed Documented in cooperative extension publications or peer-reviewed research
Well-grounded A known agronomic principle, but not formally tested for this specific pair
Traditional Time-tested gardening wisdom, limited formal research support
Last reviewed
June 29, 2026
Data version
crops_data_final · v1.0 · schema 2.9
Sources cited on this page
16 publications
Verified entries
Companion-planting claims tagged inline · zone dates verified against 5+ extensions
See all sources cited on this page
  • University of Minnesota Extension umn_ext
  • University of Maryland Extension umd_ext
  • Cornell Cooperative Extension cornell_ext
  • Iowa State University Extension iastate_ext
  • Michigan State University Extension msu_ext
  • NC State Extension ncsu_ext
  • Penn State Extension psu_ext
  • U. of Illinois Urbana-Champaign Extension uiuc_ext
  • UC Davis Postharvest Center ucd_postharvest
  • Texas A&M AgriLife Extension tamu_agrilife
  • Virginia Cooperative Extension 426-331 vce_426_331
  • Piedmont Master Gardeners piedmont_mg
  • UGA Vegetable Garden Calendar uga_calendar
  • Clemson Home & Garden Information Center clemson_hgic
  • UC IPM Statewide IPM Program uc_ipm
  • NOAA 1991-2020 Climate Normals noaa_normals

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Vol. 003 · Brussels Sprouts · plant.lifestyle

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