One of the fastest crops to harvest. Cold-hardy and can be direct sown as soon as ground can be worked. Bolts in heat -- time plantings for cool weather.
Plant window opens
Mar 18
Last chance to plant
Sep 15
Last frost
~Apr 15
Days to harvest
37–45 days
Difficulty
Easy
Plant now — Zone 5
Harvest: Apr - Jun, Oct
Harvest urgency: daily— Check and pick every day at peak season
Planting Calendar
In Zone 5, Spinach can be planted outdoors from Mar 18 — the window closes around Sep 15.
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Sow every 2 weeks for succession harvest. Mulch fall planting to extend into December.
Your zone at a finer grainNOAA 1991–2020
Zone 5 is split into two subzones. The a/b distinction affects your exact last frost date by 1–2 weeks -- meaningful for heat-sensitive crops and fruit tree hardiness.
Subzone
Last frost
First fall
Season
Min temp
5a
May 5
Oct 11
~158 days
-20 to -15°F
5b
Apr 25
Oct 17
~173 days
-15 to -10°F
plant detects your subzone from your location and adjusts planting windows accordingly.
Growing Journey
Here is what to expect at each stage — and what to do when you get there.
GerminationDay 3-10
Keep soil consistently moist but not waterlogged. Most leafy greens germinate best at 50-65°F -- they actually prefer co
SeedlingDay 5-21
Thin seedlings to the recommended spacing -- crowded leafy greens bolt faster and produce less. The thinnings are edible
EstablishedDay 14-35
Begin harvesting outer leaves now -- this encourages more growth from the centre. Do not wait for the plant to be 'finis
HarvestDay 21-60
Harvest cut-and-come-again -- remove outer leaves and let the centre keep growing. For butterhead types, harvest the who
BoltingDay 40-80
Once bolting starts the flavour changes -- harvest everything immediately. Bolted leaves are still edible but more bitte
What to Expect
Typical yield
4-6 oz per plant before bolting
At peak: Spinach is a quick crop -- harvest everything within the window
Spinach bolts fast in heat. Plan for a spring and a fall sowing rather than one long crop.
Get notified when to plant, water, and harvest your Spinach — personalized for your zone.
Grown Spinach before?or
Care Guide
Sunlight
Full sun to partial shade · 3–8 hrs/day
Watering
Regular
Spacing
4–6 inches
Soil
Rich, moisture-retentive, well-draining
Days to maturity
37–45 days
Soil pH
6.5–7.5
Plant tip · Zone 5
Sow every 2 weeks for succession harvest. Mulch fall planting to extend into December.
How to know it's ready
Pick outer leaves continuously. Harvest entire plant once it shows signs of bolting (central stem elongates).
Watering Spinach
How often
Every 2-3 days -- spinach bolts in dry heat
How much
1-1.5 inches per week
Method
Either overhead or base
Overwatering signs
Yellowing, root rot
Underwatering signs
Wilting, early bolting
Feeding Schedule
How often
every 3 weeks
Feed type
Nitrogen-rich fertilizer
Key timing
throughout growing season
NPK: high N, e.g. 10-5-5
Fast-growing, nitrogen-hungry crop. Liquid feed every 3 weeks keeps leaves large and dark green.
Example product: Fish emulsion
Reminder: every 14 days after feeding
Succession Planting
Sow every 2 weeks
Sow every 2 weeks in spring until temperatures consistently reach 75°F, then pause and restart in late August for a fall crop. Spinach bolts fast in heat and is genuinely pointless to sow mid-summer in most zones. The fall succession is often better than spring -- cooler nights and shorter days keep it sweet longer. Count back from your first fall frost to time your last sowing.
Direct
Direct sow 4-6 weeks before last frost. Cold-tolerant -- sow very early. Poor transplant candidate.
Container friendly · Minimum 1 gallons
Excellent container crop -- shallow roots. Even window boxes work. 6-8 inches deep minimum.
Thinning Required
When to thin
When 2 inches tall
Final spacing
4-6 inches
Snip at soil level. Thinnings are edible.
Spinach germinates in clusters -- each seed capsule contains multiple seeds. Thin promptly for best yield.
Bolting risk: high
Triggers: Heat, long days -- very day-length sensitive
Prevention: Plant very early (can handle frost). Choose slow-bolt varieties (Bloomsdale, Tyee). Autumn plantings last much longer. Shade cloth in spring heat.
Spinach is the most difficult to keep from bolting in warm weather -- succession sow and accept the short season.
Companion Planting
Some plants help Spinach thrive. Others compete or cause problems.
Grows well with
StrawberriesPeasRadishes
Keep apart from
Fennel
Common Problems
Something went wrong? Here is what likely happened and what to do differently next time.
Frost or cold damage
What happened: Most leafy greens actually handle light frost well once established -- it can even improve flavour. But young seedlings are more vulnerable. If the damage happened at the seedling stage, a late frost likely caught them.
Next season: Cover seedlings with fleece if frost threatens in the first few weeks. Established leafy greens generally recover from light frost on their own.
Pests or disease
What happened: Slugs love leafy green seedlings, especially in wet conditions. Downy mildew affects plants in humid, overcrowded conditions. Flea beetles leave tiny holes in leaves -- especially on arugula and kale.
Next season: Thin seedlings properly to allow airflow. Protect from slugs in the first few weeks. Row cover helps with flea beetles on susceptible varieties.
Too much water or bolting
What happened: Leafy greens in waterlogged soil develop root rot quickly. More commonly, warmth and long days trigger bolting -- the plant sends up a flower stalk and the leaves become bitter. This is the plant completing its lifecycle, not a failure of care.
Next season: Bolting is largely about timing. Sow earlier in spring or switch to a fall sowing -- cooling temperatures signal the plant to keep producing leaves rather than flowering.
Too little water
What happened: Irregular watering is a major bolting trigger in lettuce and spinach. A dry spell followed by heat pushes them to flower and seed rapidly.
Next season: Keep moisture consistent -- mulching around leafy greens makes a real difference. Water in the morning so leaves dry during the day.
Bolted too quickly
What happened: Heat and long days cause most leafy greens to bolt -- this is the most common reason they fail. The plant is not dying, it is doing what it is designed to do. Once bolted the leaves become bitter and inedible quickly.
Next season: The fall sowing is almost always more successful than spring for leafy greens. Cooling temperatures give you longer, slower-bolting plants. Shade cloth can also extend the spring crop by a couple of weeks.
What went wrong
Something didn't work out? Here is what likely happened and what to do differently next season.
Frost or cold damage
What happened: Most leafy greens actually handle light frost well once established -- it can even improve flavour. But young seedlings are more vulnerable. If the damage happened at the seedling stage, a late frost likely caught them.
Next season: Cover seedlings with fleece if frost threatens in the first few weeks. Established leafy greens generally recover from light frost on their own.
Pests or disease
What happened: Slugs love leafy green seedlings, especially in wet conditions. Downy mildew affects plants in humid, overcrowded conditions. Flea beetles leave tiny holes in leaves -- especially on arugula and kale.
Next season: Thin seedlings properly to allow airflow. Protect from slugs in the first few weeks. Row cover helps with flea beetles on susceptible varieties.
Too much water or bolting
What happened: Leafy greens in waterlogged soil develop root rot quickly. More commonly, warmth and long days trigger bolting -- the plant sends up a flower stalk and the leaves become bitter. This is the plant completing its lifecycle, not a failure of care.
Next season: Bolting is largely about timing. Sow earlier in spring or switch to a fall sowing -- cooling temperatures signal the plant to keep producing leaves rather than flowering.
Too little water
What happened: Irregular watering is a major bolting trigger in lettuce and spinach. A dry spell followed by heat pushes them to flower and seed rapidly.
Next season: Keep moisture consistent -- mulching around leafy greens makes a real difference. Water in the morning so leaves dry during the day.
Bolted too quickly
What happened: Heat and long days cause most leafy greens to bolt -- this is the most common reason they fail. The plant is not dying, it is doing what it is designed to do. Once bolted the leaves become bitter and inedible quickly.
Next season: The fall sowing is almost always more successful than spring for leafy greens. Cooling temperatures give you longer, slower-bolting plants. Shade cloth can also extend the spring crop by a couple of weeks.
Pests & Diseases
Know what to look for before it gets out of hand — early identification is the most important step.
Leafminers
pesthigh
What to look for
Pale winding tunnels or blotchy translucent patches between the upper and lower leaf surfaces. Affected tissue turns brown and the leaf is unusable even though the rest of the plant looks healthy.
Cause
Spinach leafminer (Pegomya hyoscyami) and vegetable leafminer larvae feed inside the leaf. Beets and Swiss chard host the same pest, so nearby plantings spread the problem.
Organic treatment
Contact insecticides do not reach larvae inside the leaf. Remove and destroy infested leaves as soon as trails appear. Check 2-3 times a week in spring.
Prevention
Floating row cover from sowing through harvest -- the adult fly cannot lay eggs through it. Rotate away from beets, chard, and last year's spinach location. Till in old crop residue.
Aphids
pestmedium
What to look for
Clusters of small green or gray soft-bodied insects on undersides of leaves. Leaves curl and yellow. Sticky honeydew may develop into sooty mold.
Cause
Green peach aphid (Myzus persicae) is the primary species on spinach; cotton-melon aphid also occurs. Green peach aphid also vectors several spinach viruses, so even small populations can cause disproportionate damage.
Organic treatment
Blast off with water. Insecticidal soap or neem oil on leaf undersides. Ladybugs and lacewings provide effective control on unprotected crops.
Prevention
Floating row cover excludes aphids and their virus transmission. Control weeds nearby, which host aphids in the off-season. Avoid excess nitrogen.
Slugs & snails
pestmedium
What to look for
Large irregular holes chewed in leaves, often starting at the leaf margin. Silvery slime trails visible on leaves and soil in early morning. Damage worst in cool damp weather.
Cause
Several slug and snail species feed at night, hiding in mulch and debris during the day. Spinach's tender low-growing leaves are especially exposed.
Organic treatment
Iron phosphate bait (labeled for vegetable gardens and safe around pets) scattered thinly around beds. Hand-pick at night with a flashlight. Beer traps set at soil level.
Prevention
Clean up leaf debris and boards where slugs hide. Water in the morning so soil surface dries by evening. Copper tape around raised beds deters crossings.
Downy mildew
diseasehigh
What to look for
Yellow or pale green irregular patches on the upper leaf surface. Undersides show a fuzzy gray-violet mold in humid conditions. Badly infected leaves yellow entirely and collapse.
Cause
Peronospora effusa (formerly P. farinosa f. sp. spinaciae), an oomycete. Favored by cool wet weather with long leaf-wetness periods. Overwinters on crop residue and seed.
Organic treatment
Remove and destroy affected leaves at first sign. No effective organic fungicide cure once established.
Prevention
Plant downy-mildew-resistant varieties -- resistance is widely available and is the single best control. Water at soil level, not overhead. Space plants for airflow. Rotate away from spinach for 2-3 years.
White rust
diseasehigh
What to look for
Small white blister-like pustules on undersides of leaves, sometimes with yellow chlorotic spots on the upper surface above each cluster. Heavily infected plants weaken and collapse.
Cause
Albugo occidentalis, an oomycete. Favored by cool humid nights (optimum 54°F germination) and mild days. Overwinters as thick-walled oospores in soil. TAMU lists white rust as the major disease of spinach in parts of the South.
Organic treatment
Remove infected plants. Copper-based fungicide labeled for spinach may slow spread if applied early.
Prevention
Plant white-rust-resistant varieties; most modern cultivars with white-rust resistance also carry Fusarium resistance. Rotate out of spinach for 3+ years. Avoid overhead irrigation.
Cercospora leaf spot
diseasemedium
What to look for
Numerous small circular spots with pale tan to off-white centers and reddish-purple margins. Spots may coalesce and cause extensive leaf loss. Heavy pressure in late summer.
Cause
Cercospora beticola fungus, the same pathogen that causes Cercospora leaf spot on beets and Swiss chard. Favored by warm temperatures (75-85°F), high humidity, and long nighttime leaf wetness.
Organic treatment
Remove affected leaves. Copper or biological fungicides (Bacillus subtilis products) applied preventively during humid stretches.
Prevention
Rotate out of beets, chard, and spinach for 2-3 years. Control weeds in the Chenopodium family (lambsquarters, pigweed) that host the pathogen. Drip-irrigate rather than overhead.
Fusarium wilt
diseasemedium
What to look for
Plants yellow and wilt starting with older lower leaves. Roots turn black. Stunted plants fail to head up. Worse on heavy soils and during warm weather stretches, which shorten the cool-season spinach window.
Cause
Fusarium oxysporum f. sp. spinaciae, a soil-borne fungus. Can persist in soil for years. Beets and Swiss chard can host the pathogen without showing symptoms, spreading it silently.
Organic treatment
No effective cure once plants are symptomatic. Remove and destroy infected plants.
Prevention
Plant resistant cultivars (most white-rust-resistant varieties are also Fusarium-resistant). Long rotations out of spinach, beets, and chard. Avoid waterlogged soils.
Recommended Varieties
Bloomsdale Long Standing (bolt-resistant, heirloom)
Tyee (extremely bolt-resistant, very reliable)
Space (smooth leaf, easy to wash)
Avon (heavy yielder)
Tyee is the most bolt-resistant variety available -- significantly extends the harvest window in spring.
Crop Rotation — rotate every 2 years
Leafy green
Avoid planting after: Beet family (same diseases)
Good to follow: Legumes (fix nitrogen that leafy crops need)
Rotate leafy greens to avoid leaf miner buildup.
Storing Your Harvest
Room temp
1 day
Fridge
3-5 days -- very perishable
Freezer
Blanch 2 minutes, squeeze dry, freeze. Excellent.
Spinach wilts fast -- harvest and use promptly, or freeze.
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Weather watch
plant monitors these conditions and sends an alert the moment they are forecast for your location.
Heat Stress
Heat alert -- harvest your greens now
Hot weather is the enemy of leafy greens. They bolt quickly and flavour turns bitter fast. Harvest as much as you can before the heat arrives. Shade cloth can buy you another week in marginal temperatures.
HIGH priority
Late Frost
Unexpected frost -- protect young greens
Most leafy greens handle light frost well once established, but young seedlings need protection. Cover with fleece tonight if frost is forecast.
MEDIUM priority
High Humidity
High humidity -- watch for downy mildew
Humid conditions encourage downy mildew on leafy greens. Ensure good airflow between plants and avoid watering late in the day. Pick regularly to keep the plant open.
LOW priority
Moon phase planting
Traditional growers have used lunar cycles to time planting and harvest for centuries. The moon affects moisture levels in soil and sap flow in plants.
Above-ground crop
Waxing moon -- new moon to full moon
Plant and harvest on a waxing moon. Energy draws upward into leaves, stems, and fruit. Germination is strongest in the days after the new moon.
Lunar phase guide
New moon → Full moon
Waxing phase
Best for planting above-ground crops. Sap rises, germination is stronger. Good for transplanting.
Full moon → New moon
Waning phase
Best for harvesting, pruning, and root crops. Energy draws downward. Good for dividing perennials.
Full moon
Peak moisture
Avoid planting -- seeds may rot in high-moisture conditions. Good for harvesting crops to eat fresh.
New moon
Rest period
Avoid planting or transplanting. Best for soil preparation, weeding, and composting.
Common questions
In Zone 5, direct sow spinach outdoors Mar 18 - Apr 8, Aug 25 - Sep 15 after your last frost of approximately Apr 15. Sow every 2 weeks for succession harvest. Mulch fall planting to extend into December.
Zone 5 has an average last spring frost around Apr 15 and a first fall frost around Oct 15. These vary by location — the plant app uses your ZIP code with NOAA data for precision.
Good companions for spinach include Strawberries, Peas, Radishes. Avoid planting near Fennel.
Spinach typically takes 37–45 days to harvest in Zone 5. Expected harvest window: Apr - Jun, Oct.
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