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

Broccoli

in Zone 7, this week

Broccoli is a cool-weather vegetable grown for its green head, which is really a cluster of flower buds you pick before they open. It grows best in spring and fall, not summer heat, and keeps making smaller side shoots after you cut the main head. Broccoli is a cool-season brassica grown for its tight head of immature flower buds, harvested before the buds open. It performs best in the cool shoulders of spring and fall, bolts or fails to head in summer heat, and rewards a steady supply of moisture and nitrogen. After the central head is cut, most types keep producing smaller side shoots.

Broccoli mature plant
Fig. 01 · Broccoli, mature Zone 7
Mature in
55-75d
from transplant
Sunlight
Full sun
6-8 hrs daily
Water
Regular
1.5 inches / week
Spacing
12-24"
between plants
Soil pH
6-6.5
slightly acidic
Today · in your zone

What's happening right now

July 24 · Zone 7 · Stage 01 · Germination

Off-season for broccoli in zone 7.

Your climate region in Zone 7
The season at a glance

Planting calendar

In Zone 7, broccoli can be planted February through March, then again September, skipping the summer heat. Start indoors Jan 25 - Feb 15. Harvest runs April through May.

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
plant
indoors
plant
plant
too late
too late
too hot
too hot
indoors
plant
too late
too late
too early
harvest
harvest
harvest
harvest
harvest
indoors
plant out
harvest
Get a head start indoors It is too hot for broccoli to form heads outside right now, but you can start seeds indoors now for a fall crop. Move them outside once daytime highs cool to around 86°F.Too hot for broccoli to form heads outside now. Start seeds indoors for a fall crop. Set transplants out once daytime highs cool to about 86°F.
Above-ground cropBest planted on a none moon
Seasoned
Extend the harvest in zone 7+

A second planting

Plant broccoli in spring and again in late summer for fall, in small batches a couple of weeks apart, instead of all at one time. Skip the hottest part of summer, since broccoli will not form good heads in the heat.Broccoli crops in the cool shoulders of the year, so plant in small batches every 2 to 3 weeks within the spring window and again in late summer for fall, rather than all at once. The spring window is short because heads must size up before summer heat arrives, so most gardens fit only a sowing or two before the midsummer gap; the fall planting, heading into cooling weather, is often the more reliable crop.

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1plant
indoors
plant
plant
harvest
harvest
harvest
2plant
indoors
plant
harvest
harvest
harvest
indoors
plant out
growing
harvest
1Main crop
2Second planting
The season, mapped

Seed to garden

You can start broccoli indoors or buy young plants. For a spring crop, start seeds about 5 to 7 weeks before you plant out, and set plants in the garden a couple of weeks before your last frost. For fall, start them in mid to late summer and plant out as the heat eases. Use small, healthy plants, not big leggy ones, and let them get used to the outdoors over a week before planting.For the spring crop, start seeds indoors about 5 to 7 weeks before setting out and transplant roughly 2 to 4 weeks before the last frost; broccoli tolerates light frost. For fall, start transplants in mid to late summer, about 4 to 6 weeks before setting them out as the heat breaks, or direct sow. Set out young, well-rooted transplants with 4 to 6 true leaves, since oversized or cold-shocked transplants are prone to buttoning (tiny premature heads). Harden plants off over 7 to 10 days.

  1. 01
    Sow indoors →
    Jan 25 - Feb 15
    Start about 5 weeks before your last frost
  2. 02
    Transplant out →
    Feb 22 - Mar 15
    After hardening off
  3. 03
    First harvest
    From Apr 26
    55-75 days from transplant
Start method
Both
Soil temp
40-86°F
Hardening off
7-10 days
From seed to fruit

The growing journey

Stage 01 · Germination
01
Germination
Days 5-14 · current stage
In about 5 to 10 days, your seeds sprout and push up their first two little leaves, called seed leaves (the cotyledons).Seeds sprout in about 5 to 10 days at soil temperatures of roughly 60 to 75°F, pushing up two seed leaves (cotyledons).
Keep the soil damp and warm. Once you see the first real broccoli leaves (true leaves) after the seed leaves, thin out crowded seedlings.Keep the seed-starting mix evenly moist and warm; thin or pot up once the first true leaves appear.
FROM PLANT · Start your seeds indoors where it's about 60 to 75°F. They sprout quickly, in 5 to 10 days, and need bright light right away or they'll get leggy.Start broccoli seeds indoors at 60 to 75°F; germination is fast, usually 5 to 10 days, and seedlings stretch if light is weak after they emerge.
FROM PLANT · Plant the seeds about a quarter to half an inch deep in damp seed-starting mix, and keep it evenly moist while they sprout.Sow about 0.25 to 0.5 inch deep into a moist seed-starting mix; broccoli germinates reliably across a wide soil-temperature range as long as moisture stays even.
02
Seedling
Days 14-35
The seedlings grow their real leaves and a stronger stem. They're ready to move outside when they have about 4 to 6 true leaves, usually 5 to 7 weeks after sowing.Young plants develop true leaves and a sturdy stem; broccoli is ready to transplant at about 4 to 6 true leaves, roughly 5 to 7 weeks from sowing.
Before planting outside, harden off the seedlings: set them outdoors for a little longer each day over about a week so they adjust. Plant them while they're still young and small, not overgrown, or they may make tiny premature heads.Harden off seedlings over several days before transplanting; set out young plants rather than oversized ones to avoid buttoning.
FROM PLANT · Move seedlings outside when they have 4 to 6 real leaves, around 5 to 7 weeks old. Planting ones that are too old or pot-bound can cause tiny premature heads.Transplant at 4 to 6 true leaves, about 5 to 7 weeks old; older, root-bound starts are the classic trigger for buttoning.
FROM PLANT · Toughen up your seedlings over about a week before planting them out, and pick a stretch of cool, steady weather rather than just before a hot spell.Harden off over 7 to 10 days before setting out, and choose a cool, settled spell rather than the front edge of a warm-up.
03
Established
Days 35-60
Once planted out, the broccoli puts on lots of big blue-green leaves for a few weeks. This leafy growth comes before any head appears.After transplanting, the plant settles in and builds a leafy frame of large blue-green leaves over several weeks before any head forms.
Feed the plant some nitrogen as it grows and keep it evenly watered. Check the leaves for green caterpillars and aphids during this stage.Side-dress with nitrogen as the plant grows, keep moisture even, and watch for cabbageworms and aphids while the frame fills out.
FROM PLANT · Space plants about 12 to 24 inches apart, and feed them nitrogen as they grow leaves. Their roots are shallow, so put the food near the plant.Space plants about 12 to 24 inches apart and side-dress nitrogen as the leafy frame builds; broccoli's shallow roots feed best from nutrients placed near the plant.
FROM PLANT · Water steadily, about 1 to 1.5 inches a week, while the plant builds its leaves. Letting it dry out or get stressed now leads to poor heads later.Keep moisture even at roughly 1 to 1.5 inches per week through this stage; an early growth check from drought or heat sets up buttoning and loose heads later.
04
Head forming
Days 55-90
A tight head of tiny green flower buds appears in the center of the plant and grows bigger. The buds should stay green and closed.A tight central head of immature flower buds appears in the growing tip and enlarges; the buds should stay blue-green and closed.
Keep watering steadily and check the head often. When it's full-sized but the buds are still tight and closed, get ready to cut it. Hot or stressful weather now can make the head loose or cause it to flower.Keep water steady and watch closely; once the head is full-sized but still tight, prepare to cut. Heat or stress here causes buttoning, bolting, or loose heads.
FROM PLANT · When the head shows up, keep watering steadily and check it every day. Hot days over about 86°F and warm nights now can make the head loose or cause it to flower.Once the head appears, keep water steady and watch daily; heat above about 86°F by day and warm nights during heading cause bolting and loose, open heads.
FROM PLANT · Try to keep the head itself dry when you water, because a wet head in cool, damp weather can rot or get downy mildew.Keep developing heads dry when you water, since wet heads in cool, humid weather invite rot and downy mildew.
05
Harvest
Days 90-110
The main head is full-sized, the buds are still tight and closed, and there's no yellow. This is the moment to cut it, before the buds open into yellow flowers.The central head is full-sized with tight, closed buds and no yellow showing; this is the moment to cut, before the buds open into flowers.
Cut the main head with about 6 inches of stem while the buds are still tight. Cutting it on time is what makes the plant grow side shoots next. Harvest in the cool morning if you can.Cut the central head with about 6 inches of stem while buds are tight; cutting on time triggers side shoots. Harvest in the cool of the morning.
FROM PLANT · Cut the main head while the buds are tight and green with no yellow, taking about 6 inches of stem. Cutting on time is what makes the plant grow side shoots next.Cut the central head while buds are tight and blue-green with no yellow, taking about 6 inches of stem; harvesting on time is what drives the side-shoot crop.
FROM PLANT · Pick in the cool morning and get it into the fridge soon. Broccoli's quality drops within a few days, so harvest close to when you'll eat it.Harvest in the cool of the morning and chill promptly; head quality drops within a few days, so cut close to when you will use it.
06
Side shoots
Days 110-150
After you cut the main head, smaller broccoli florets grow on side branches lower down the stem. These keep coming for several weeks in cool weather, especially on certain varieties.After the central head is cut, smaller florets form on side shoots from leaf joints down the stem, especially on side-shoot varieties, continuing for several weeks in cool weather.
Keep cutting the side shoots while their buds are tight, which encourages even more. Keep feeding and watering. When it gets too hot or freezes hard, the plant is done and you can pull it.Keep harvesting side shoots while buds are tight to encourage more; keep feeding and watering. Pull the plant when heat or hard frost ends production.
FROM PLANT · After cutting the main head, keep picking the side shoots while their buds are tight, which brings more. They keep coming for weeks in cool weather, especially on certain varieties like De Cicco.After the main cut, keep harvesting side shoots while their buds are tight to encourage more; production continues for several weeks in cool weather, especially on De Cicco-type varieties.
FROM PLANT · Keep feeding and watering while the side shoots keep coming. Once it gets too hot or freezes hard and the shoots stop, the plant is done and you can pull it.Keep feeding and watering through the side-shoot run; pull the plant once summer heat or a hard freeze ends production and quality falls off.
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

Broccoli likes rich, loose soil that holds moisture but drains well. Mix in compost before planting.

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
12-24 inches
Days to maturity
55-75 days from transplant
Soil pH
6 to 6.5
Container OK?
Yes · 5+ gal pot
Germination temp
40-86°F
Soil chemistry

Soil pH for broccoli

Preferred
6 to 6.5
Tolerated
5.5 to 6.8

Broccoli grows best in slightly acidic to near-neutral soil. A simple soil test tells you where you stand.Aim for a pH near 6.0 to 6.5. Broccoli still does fine across 5.5 to 6.8, and holding the soil at or above roughly 6.8 to 7.0 also helps suppress clubroot, a key brassica soil disease.

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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 season.
Amount
Aim for roughly 1 to 1.5 inches of water a week.About 1 to 1.5 inches per week, more as heads bulk up.
Method
Water at the base of the plant, not over the head.Water at the soil line with drip or a soaker hose where possible.
Signs of trouble
Too much water
Leaves yellow and the plant looks waterlogged.Yellowing lower leaves and stunted, soft growth; broccoli is prone to root rot in soggy soil.
Too little water
Wilting and small heads.Wilting, checked growth, and small or bitter heads; any stall in growth hurts quality.
Feeding rhythm

Feeding

Frequency
twice a season
Type
Nitrogen-rich fertilizer
When to start
starter at transplanting, then side-dress

Broccoli is hungry and needs steady feeding. Give it a feed when you transplant, again about 3 weeks later, and once more after you cut the main head so it makes side shoots.Broccoli is a heavy feeder with a high nitrogen requirement and a small root zone, so place feed near the plant. Use a starter fertilizer at transplanting, side-dress with nitrogen about 3 weeks later, and feed again after cutting the central head to push side shoots. Avoid overdoing nitrogen, which can give soft, poor-quality growth.

N · P · K = 21-0-0

Use a nitrogen-rich feed such as blood meal or a balanced vegetable fertilizer.High N for leafy growth; e.g. 21-0-0 side-dress or blood meal. Starter feed at transplant.

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

Companion planting

Broccoli does well next to aromatic herbs, onions, and quick cool-season crops like lettuce. The main things to keep it away from are other cabbage-family plants, which share its diseases. Most broccoli companion pairings are traditional rather than research-tested. The pairings worth acting on are practical ones: aromatic herbs and alliums as scent-based deterrents, and lettuce or spinach as cool-season intercrops that use space and light before broccoli fills in. The well-grounded caution is to separate broccoli from other brassicas, which share clubroot and cabbage-family pests, a rotation and disease principle more than a tested adjacency effect.

Pest deterrent
Marigolds
A traditional all-purpose companion said to deter cabbage moths and aphids. The broad pest-deterrent claim is folklore rather than a documented broccoli-specific effect. Traditional
interplant nearby
Other
Dill
Dill is a classic friend for broccoli. Its strong smell is said to put off cabbage pests, and its flowers bring in helpful insects.Dill works for broccoli through beneficial insects. Its umbel flowers are a magnet for parasitoid wasps and predators like hoverflies and ladybeetles that prey on the aphids and cabbage caterpillars broccoli attracts, and extension trial work pairing aromatic herbs and umbels with brassicas has shown reduced caterpillar damage. Let some dill flower to get the benefit, and site it nearby rather than crowding the broccoli, since flowering dill gets tall and lanky. Research-backed
Onions
Onions are a traditional neighbor for broccoli; their smell is said to help keep cabbage pests away.Onions are one of the better-supported broccoli companions. Their pungent allium scent helps mask the broccoli and deter the cabbage-family pests, loopers, cabbageworms, and root maggots, that hunt partly by smell, and extension trial work including onion in a mix with broccoli showed reduced caterpillar damage. Alliums are shallow-rooted and undemanding, so they tuck around broccoli without competing for much. Research-backed
Lettuce
Lettuce grows fast and low, so you can tuck it between young broccoli plants to use the space while the broccoli fills in.Lettuce and broccoli interplant well on structure and timing rather than chemistry. Lettuce is shallow-rooted and quick, broccoli is taller and slower, so the lettuce uses the open ground and light between young broccoli plants and is harvested before the broccoli canopies over. It is an efficient space pairing; expect a tidy use of the bed, not pest protection. Traditional
Leafy green
Spinach
Another quick cool-season green that shares broccoli's window and fits the same space-driven intercrop role along the bed edge. Traditional and low-risk rather than a documented benefit. Traditional
interplant along edges
Trap crop
Nasturtiums
Nasturtiums are often planted as a trap crop for cabbage aphids near brassicas. Trap cropping is a documented principle, but it works best for moderately mobile pests and is not a tested broccoli-nasturtium pairing, so treat it as a plausible aid rather than a proven control. Well-grounded
interplant nearby
Vegetable
Celery
A long-standing brassica companion said to deter cabbage white butterflies. Traditional lore with no documented broccoli-specific support. Traditional
interplant nearby
Keep apart from
Other brassicas Keep broccoli away from other cabbage-family plants like cabbage, cauliflower, and kale. They share the same pests and diseases, so planting them together makes problems worse.Planting broccoli cheek-by-jowl with its brassica relatives, cabbage, cauliflower, kale, Brussels sprouts, concentrates the whole family's shared pests (cabbage worms, loopers, flea beetles, root maggots) and shared diseases in one spot, and repeated same-family planting lets soil-borne problems like clubroot build up. Spread brassicas out and rotate where they grow each year rather than blocking them together. Well-grounded
Strawberries A traditional caution that broccoli and strawberries inhibit each other. There is no documented mechanism or T1 support; it persists as folklore. Traditional
Tomatoes Tomatoes and broccoli are both heavy feeders and a traditional list pairs them as competitors for nutrients and space. Inter-plant competition is a real general concept, but the specific bad pairing is not documented for broccoli, and the two also want different seasons. Treat it as low-priority caution. Traditional
Provenance tagged inline · see methodology for the labeling system Key
Harvest signals

When to pick

Cut the main head while it is firm, green, and tight, before the little buds open into yellow flowers. More small shoots grow afterward.Cut the central head while the buds are tight, blue-green, and still closed, before any yellow flowers show, taking about 6 inches of stem. Side shoots then form for later picking.

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Yield

What to expect

Each plant gives you one main head about 4 to 8 inches wide, and then a few weeks of smaller side shoots after you cut that main head. How much you get depends a lot on the variety and on the weather staying cool.Expect one central head of roughly 4 to 8 inches across per plant, followed by a steady run of smaller side shoots over several weeks once the main head is cut. Total yield depends heavily on variety and on whether the weather stays cool enough to keep the side shoots coming.

The big harvest is the main head, which fills out over a week or two. After you cut it, the side shoots come on strongest in the following cool weeks, then slow down once it gets hot or freezes. Some varieties, like De Cicco, are bred to make lots of side shoots.The central head matures across a week or two as it reaches full size, and that is the single largest harvest. Side-shoot production then peaks in the cool weeks after the main cut, especially on side-shoot-heavy varieties like De Cicco and Calabrese, and tails off as heat or hard frost arrives. Here's the key thing: cutting the main head while its buds are still tight is what makes the plant produce side shoots, so harvesting on time gives you more overall. It's easy to wait too long and let the head bloom, which makes it less tasty and cuts the side-shoot harvest short.Cutting the central head while the buds are still tight is what triggers the side shoots, so a timely first harvest actually increases total yield. New growers often wait too long and let the head loosen or flower, which both ends the side-shoot run early and gives a coarser main head.

What changes yield
Variety: side-shoot-heavy types (De Cicco, Calabrese) keep producing after the main cut; some hybrids put nearly everything into one large central head and give few shoots.Temperature: cool weather through heading and the side-shoot period sustains yield; heat triggers buttoning, bolting, and loose heads.Harvest timing: cutting the central head while buds are tight drives side-shoot production; a late cut ends it early.Nitrogen and even moisture: this heavy feeder needs steady nitrogen and consistent water to size both the central head and the side shoots.
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Pick your variety

Recommended varieties

Green Magic and Belstar are easy, dependable choices. For spring, pick a fast or heat-tolerant variety so it heads before it gets hot; for fall, a hardy one like Waltham 29 works well. De Cicco gives lots of small side shoots over a longer time.Match the variety to the slot: fast, heat-tolerant types like Green Magic for spring, and longer-cycle, cold-hardy types like Waltham 29 for fall. Side-shooting heirlooms such as De Cicco stretch the harvest, while hybrids give more uniform central heads. Where clubroot or other brassica diseases are a concern, look for resistant cultivars.

Calabrese
The classic green Italian heading broccoli and the most widely grown type; a dependable open-pollinated choice with a good central head and side shoots.
Green Magic
An early, reliable hybrid with some heat tolerance, which makes it a good pick for the spring-into-warm-weather crop.
Belstar
A widely adapted hybrid that does well in both spring and fall, popular in organic gardens.
De Cicco
An heirloom with a smaller main head but heavy, prolonged side-shoot production, good for a long picking window.
Waltham 29
A cold-hardy heirloom bred for fall and overwintering, with uniform heads that finish in cool weather.
Sun King
A heat-tolerant hybrid that holds up better in warmth, useful at the warm edges of the season.
Off the vine

Storing your harvest

Room temp
Don't leave broccoli out at room temperature. It goes yellow and tough fast in the warmth, so put it in the fridge as soon as you can after picking.Broccoli is highly perishable and does not hold at room temperature; warmth quickly yellows the buds and turns the heads tough and strong-flavored. Use it within a day if it must sit out, and refrigerate as soon as possible after cutting.
Fridge
Store broccoli unwashed in a loose bag in the fridge's crisper drawer, where it stays good for about a week. Wait to wash it until you're ready to cook, since washing first makes it spoil faster.Refrigerate unwashed in a loose or perforated bag in the crisper; broccoli keeps its quality for roughly 1 week this way. Cold and humidity slow the buds from opening, while washing before storage traps moisture in the head and speeds rot.
Freezer
Broccoli freezes well if you blanch it first. Cut it into florets, boil them for about 3 minutes, then cool them right away in ice water, drain, and freeze. The quick boil keeps the broccoli from losing its color and flavor in the freezer.Broccoli freezes well once blanched: cut into florets, blanch about 3 minutes in boiling water, cool quickly in ice water, drain, and freeze. Blanching halts the enzymes that would otherwise cause off-flavors and loss of color and texture in storage.
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When something goes wrong

Common problems

01 of 04
What happened You got a tiny, button-sized head on a small plant instead of a full one. This happens when young broccoli gets stressed, usually from heat or from planting seedlings that were too old or pot-bound, so it rushes to make a head before it grows big enough. It's tempting to think the seed was bad, but a stressful start is almost always the reason. Next time, plant young, healthy seedlings with 4 to 6 real leaves into cool weather and keep them growing without any setback.You got a tiny, button-sized head on a small plant instead of a full one. This happens when broccoli is stressed early, often from heat or from transplants that were too old or root-bound when set out, and the plant heads prematurely before building a leafy frame. It is easy to blame poor seed, but the usual cause is a checked start. Next time set out young, vigorous transplants with 4 to 6 true leaves into cool conditions and keep them growing steadily without a stall. Next season Plant young seedlings (4 to 6 real leaves) into cool weather, and don't let them get stressed by heat, dryness, or sitting too long in their pots.Set out young transplants (4 to 6 true leaves) into cool weather and avoid any growth check from heat, drought, or being root-bound.
02 of 04
What happened The plant shot up a tall stalk with yellow flowers instead of making a tight head. Broccoli bolts (flowers early) when heat and long days tell it to bloom, and once that happens the head won't form. A common mistake is planting too late in spring so the heat catches it. Next time, plan so the head forms in cool weather, use fast heat-tolerant varieties in spring, and grow a fall crop that heads as it cools down.The plant shot up a flower stalk with yellow blooms instead of forming a tight head. Broccoli bolts when heat and long days signal it to flower, racing past the head stage; once it bolts the head cannot re-form. Growers often plant too late in spring and get caught by early heat. Next time time the crop so heading lands in cool weather, choose heat-tolerant short-cycle varieties for spring, and plant a fall crop that heads as the weather cools. Next season Plan your spring and fall crops so the heads form while it's cool, and pick fast, heat-tolerant varieties for spring.Time spring and fall crops so heads form in cool weather; use fast, heat-tolerant varieties for spring.
03 of 04
What happened The plant made plenty of leaves but only a loose, open head, or no head at all. This usually comes from heat while the head is forming, or from a nitrogen problem: too little and the head can't fill, too much late on and the plant just grows leaves. People often wait for a loose head to tighten up, but it won't. Next time, feed nitrogen steadily, water evenly, and time the crop so the head forms in dependably cool weather.The plant grew lots of leaves but made only a loose, open head or none at all. This usually comes from heat during head formation or from a nitrogen imbalance: too little starves the head, while a late flush of too much pushes leafy growth over heading. People often keep waiting for a loose head to tighten, but it will not. Next time keep nitrogen steady and even, ensure consistent moisture, and time the crop so heading happens in reliably cool weather. Next season Feed and water evenly, and aim for the head to form in cool weather, not right as summer heat arrives.Keep nitrogen and moisture steady, and time heading for cool weather rather than the edge of summer heat.
04 of 04
What happened You cut the head and found a hollow, sometimes brown space inside the stem. This usually comes from a shortage of the nutrient boron, or from the plant growing so fast (often from too much nitrogen) that the stem can't keep up and splits inside. The head is usually still fine to eat, so it's more about quality than losing the crop. Next time, don't overfeed nitrogen, keep growth steady, and only add boron if a soil test shows you need it.You cut the head and found a hollow, sometimes browned cavity in the stem. This is usually caused by boron deficiency or by growth so rapid (often from heavy nitrogen) that the stem tissue cannot keep up and splits internally. The head is often still edible, so it is more a quality issue than a loss. Next time avoid overfeeding nitrogen, keep growth steady rather than pushed, and correct a confirmed boron shortage with a soil amendment based on a soil test. Next season Don't push fast growth with too much nitrogen, and only add boron if a soil test says it's low.Avoid pushing growth with excess nitrogen; correct a confirmed boron deficiency based on a soil test.
The usual suspects

Pests & diseases

Pests
Cabbageworms and cabbage loopers
P · 01
Symptoms You'll see ragged holes eaten in the leaves and head, green caterpillars on the plant, and little dark droppings. Some caterpillars loop up in the middle as they crawl.Ragged holes chewed in leaves and into developing heads, with green caterpillars and dark droppings on the foliage. Imported cabbageworms are velvety green; cabbage loopers move in a looping arch. Cause These are caterpillars that hatch from eggs laid by white butterflies and small moths. They love cabbage-family plants like broccoli and chew on the leaves and heads.The larvae of the imported cabbageworm, cabbage looper, and diamondback moth feed on brassica foliage and heads; the adults are white or brownish moths and butterflies that lay eggs on the leaves. Prevention Cover your plants with a light fabric row cover right after planting to keep the butterflies and moths from laying eggs. Clear away old cabbage-family plants, and start watching for the first white butterflies as your signal to act.Cover plants with floating row cover from transplanting to exclude the egg-laying adults; clean up brassica debris that shelters pupae, and watch for the first white butterflies as a spray cue.
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. Clear away old cabbage-family plants after harvest, since the pupae shelter in the debris.

  2. Broccoli does not need bees, so you can leave the cover on the whole time. Tuck the edges down so the butterflies and moths cannot get under it to lay eggs.Broccoli needs no pollination, so the cover can stay on through harvest; seal the edges to exclude the egg-laying adults.

  3. Check the undersides of the leaves and pick off the green caterpillars and eggs.

  4. Bt kills only caterpillars and is safe for you and for bees, but it washes off, so spray again after rain.Bt is selective for caterpillars; reapply after rain or a flush of new growth, since it does not persist.

  5. Use spinosad only if Bt and handpicking have not held. Spray in the evening when bees are not flying.A stronger organic option once the softer rungs have not held; time it to dusk to spare bees.

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

Aphids
P · 02
Symptoms You'll see clusters of tiny soft insects on the new growth, under leaves, and inside the head. Leaves curl up, and there may be a sticky coating. The waxy gray-green kind is hard to wash out of the head.Clusters of small soft-bodied insects on growing tips, leaf undersides, and tucked into the head; leaves curl and pucker, and a sticky residue and sooty mold may appear. Gray-green waxy cabbage aphids are especially hard to wash out of heads. Cause Aphids are tiny insects that suck juice from the plant. They breed fast in warm weather, and their feeding twists the leaves and gets into the heads.Several aphid species, notably the waxy cabbage aphid, suck sap from broccoli; they multiply quickly in warm weather and their feeding distorts growth and contaminates heads. Prevention Welcome helpful bugs like ladybugs that eat aphids, don't overdo the nitrogen fertilizer (lush growth attracts them), and check the new growth often so they don't reach the head.Encourage natural enemies like ladybugs and lacewings, avoid overfeeding nitrogen (which spurs the soft growth aphids favor), and inspect growing tips early so colonies do not reach the head.
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. Go easy on nitrogen fertilizer; the soft, lush growth it pushes is what aphids swarm to.

  2. Blast colonies off with a strong jet of water, hitting under the leaves and inside the head where they hide.Aim under the leaves and into the head; the waxy gray-green cabbage aphid is the hardest to dislodge and to wash out of a cut head.

  3. Ladybugs and lacewings usually clean up aphids on their own if you do not spray them off.

  4. For heavier clusters, coat the aphids directly under the leaves; repeat every few days.

  5. A contact alternative to insecticidal soap for the same aphids; coat the leaf undersides where they cluster and repeat, and spray at dusk so you do not wet foraging bees.

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

Flea beetles
P · 03
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 or kill seedlings.Tiny round shot-hole pits chewed in the leaves of young plants; the small dark beetles jump like fleas when disturbed. Heavy damage stunts or kills seedlings. 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; they are most damaging at the seedling stage when a small plant cannot outgrow the feeding. 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. Pull weedy cabbage-family relatives nearby that feed the beetles.

  2. Cover seedlings from day one. The real goal is getting them big and tough enough to outgrow the shot-hole damage.Exclude beetles from transplanting; the aim is carrying seedlings past the vulnerable stage.

  3. Only if the beetles are thick enough to stunt the seedlings.

  4. Carbaryl Rescue only

    A last resort, mainly at the seedling stage, when flea beetles can kill young plants before they get going. Spot-treat only the affected plants rather than blanket-spraying, since a broad spray can flare cabbage aphids on broccoli. Read the label and mind the days-to-harvest wait.Reserve for a seedling-stage outbreak that the softer rungs have not held, since young broccoli can be killed outright. Spot-treat affected plants; blanket coverage risks flaring cabbage aphids by knocking out their predators. Observe the label pre-harvest interval.

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

Cabbage root maggot
P · 04
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's worst in cool, wet spring 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 spring soil. 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 spring weather.The larvae of the cabbage root fly tunnel into brassica roots; the adult fly lays eggs at the base of the stem, and the maggots hatch and feed on the roots below. 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. Don't plant into cold, soggy soil, and avoid spots where you grew cabbage-family plants last year.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. The fly builds up where cabbage-family plants grew last year, so move the bed.

  2. Seal the cover at the edges right at transplanting so the low-flying fly cannot reach the stem base to lay eggs. Broccoli needs no bees, so it can stay covered.Seal row cover at the edges from transplanting to block egg-laying at the stem base; no pollination is needed, so it stays on.

  3. A tar-paper or cardboard disk laid flat on the soil around each transplant blocks the cabbage fly from laying eggs at the stem base.

No spray for this one. Prevention is the control.

Diseases
Clubroot
D · 01
Symptoms Plants wilt in the afternoon heat, stay small and yellowish, and don't bounce back. If you dig one up, the roots are swollen into lumpy, club-shaped knobs instead of normal roots.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 up, 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 causes the galls, which block water and nutrient uptake. It persists in the soil for many years and spreads in contaminated soil and water. Prevention Don't grow broccoli or its cabbage-family relatives in the same spot more than once every 3 years, or longer if you've had clubroot. Keep the soil from being too acidic, improve drainage, and clean soil off your tools so you don't spread it.Rotate brassicas on a long cycle of at least 3 years, and longer where clubroot is known, since this ties directly to the rotation plan; 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. The soil germ lasts for years, so keep broccoli and its cabbage-family relatives out of an infested bed for at least 3 years, longer where clubroot has been bad.Long rotations of at least 3 years, and longer where clubroot is established, let soil inoculum decline; there is no cure once plants are infected.

  2. Liming the soil toward neutral (pH 7.0 or above) holds clubroot back, but does not cure it.

  3. Clubroot-resistant cabbage-family varieties exist and are worth choosing where the disease keeps returning.

  4. Pull and destroy infected plants, and knock soil off tools and boots so you do not carry spores to clean beds.

No spray for this one. Prevention is the control.

Black rot
D · 02
Symptoms Yellow patches shaped like the letter V appear at the edges of the leaves, pointing inward, with black veins inside them. It can spread into the stem and rot the head.Yellow, V-shaped lesions spread inward from the leaf edges, with the veins inside the V turning black; the disease can move into the stem and rot the head. 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) that enters through leaf pores and wounds and moves through the plant's veins; it spreads in warm, wet conditions and on infected seed or transplants. 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 watering from overhead or touching wet plants.Start with clean, certified seed and healthy transplants, rotate 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. Rotate away from where cabbage-family crops grew recently.

  2. Remove and destroy infected plants, and stay out of the bed when the foliage is wet, since that spreads the bacteria.Rogue out infected plants and avoid working among wet foliage, which moves the bacteria.

  3. Start with clean, certified seed and resistant varieties; black rot often rides in on the seed.

  4. Space plants so the leaves dry fast; the bacteria spread fastest in warm, wet conditions.

  5. Copper is a protectant that can slow spread, not a cure. It will not overcome infected seed, so the cultural steps come first.Copper acts only as a protectant against bacterial spread and cannot rescue systemic or seedborne infection; lead with sanitation and clean seed.

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

Downy mildew
D · 03
Symptoms Pale yellow blotches show on top of the leaves, with fuzzy grayish growth on the underside, mostly in cool, damp weather. A bad case can mark the head.Pale yellow patches form on the upper leaf surface with a fuzzy gray-white growth underneath, mainly in cool, damp weather; severe infection can discolor the head. 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 that thrives in cool, wet, humid conditions and spreads by spores in water and air; long leaf wetness and crowded plantings favor it. Prevention Space plants so air moves between them, water at the soil instead of from above, keep the heads dry, 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, keep heads dry, 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. Space plants for good air movement and keep the heads dry; downy mildew needs long leaf wetness to take hold.Set spacing and site at planting for airflow, and water at the soil line so foliage dries quickly.

  2. Choose resistant varieties where downy mildew shows up most years.

  3. Strip off the worst-affected leaves as soon as you see the fuzzy gray growth underneath.

  4. A copper spray can slow spread in a wet spell, but it is hard to stop once the humidity stays high.

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

Verified · 2 sources View
Seasoned
Where to plant next year

Crop rotation

Do not plant broccoli or other cabbage-family crops in the same spot year after year. Waiting a few years between them helps avoid soil diseases like clubroot.Rotate so brassicas do not follow brassicas for at least 3 years, and longer where clubroot is present, since the clubroot organism persists in soil for years. Keeping soil pH at or above about 6.8 also helps suppress it.

Family
Brassica family (Brassicaceae), the cole crops
Years between
3 years
in the same bed
Avoid following
Other cabbage-family crops like cabbage, cauliflower, kale, and turnips.Other brassicas (cabbage, cauliflower, kale, Brussels sprouts, collards, turnip, radish, kohlrabi), which share clubroot and 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 broccoli season. The wording adjusts to whichever you pick: beginner or seasoned. Here are three you'll see in Zone 7.

p
plant
NaN days after last frost
Time to cut your broccoli head
Your main head should be full-sized and tight by now. Cut it while the buds are still green and closed, before any yellow flowers appear, for the best taste and to get side shoots later.
p
plant
NaN days after last frost
Time to feed your broccoli
Broccoli is a hungry plant. Feed it some nitrogen now to help it grow leaves and form a head. Put the fertilizer near the plant and water it in.
p
plant
NaN days after last frost
Hot weather warning for your broccoli
Hot weather is on the way while your broccoli is making its head. Heat can make the head loose or cause it to flower early. Keep the soil evenly watered, and cut the head soon if it's nearly full-sized.
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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 23, 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 · Broccoli · plant.lifestyle