How to grow spinach
Family Amaranthaceae. Hardy to USDA hardiness zone 3a+ (U.S. Department of Agriculture). Part shade in summer. Ready in 35-45 days.
Sun
Part shade in summer
Spacing
4-6 in
Days to harvest
35-45 days
Hardiness
Zone 3a+
What growers actually recorded
Loading zone 7b results…
When to plant spinach
- Direct sow: ~-4 weeks after last frost.
Companion plants for spinach
Plant with: Strawberry, Radish.
Common pests & problems
Leaf miner. Row cover.
Feeding & fertilizer
N-P-K ratio: Balanced 5-5-5
Organic options: Compost + wood ash · Kelp meal for micronutrients · Fish emulsion every 3 wks
When to feed: Bed prep with compost + kelp, one side-dress mid-season.
Watch for: Pale leaves = light nitrogen boost. Suspect a micronutrient problem? Get a soil test first; boron in particular is toxic just above the helpful dose.
N = nitrogen (leaves), P = phosphorus (roots and flowers), K = potassium (fruit and disease resistance). How to read a fertilizer label →
Grower's tip
Bolts fast in heat. Grow it early spring and again as days shorten in fall.
When to plant spinach in your zone
Free month-by-month sowing and transplanting lists, built from frost dates for your USDA (United States Department of Agriculture) hardiness zone.
Soil & water for spinach
Soil & pH
6.5-7.5: beets/spinach hate acidic soil
Well-drained loam. Add lime if pH is below 6.5 or roots stall.
Compost worked in at bed prep. Only add boron if a soil or tissue test shows a shortage; the safe range is narrow.
Watering
1 in / week
Consistent moisture. Drought stress makes spinach bolt in a week.
Beets and chard tell the truth with their leaves: if lower leaves are soft and yellow while the top stays green, the soil is staying too wet, not too dry. If leaves are thin and cupped upward, water.
Knowing when to harvest
- Baby leaves 3-4 in; full 6+ in.
- Bolting starts as a central stem shooting up: harvest whole plant immediately.
- Cut-and-come-again works twice on most varieties.
Storing & keeping
Crisper 5-7 days; blanch 1 min and freeze in portions.
What to expect
Per plant: 4-8 oz per plant
Per sq ft: 1 lb / sq ft in dense plantings
Troubleshooting spinach
Fast bolting
Likely cause: Day length + heat
What to do: Grow in shoulder seasons; choose bolt-resistant varieties like Space or Renegade.
Silvery leaf mines
Likely cause: Leaf miner
What to do: Row cover from sowing; remove and destroy affected leaves.
Varieties worth the space
Not every name in a seed catalog. These are the ones growers order again, with what each one is actually good at and what it asks of you.
Bloomsdale Long Standing
Heirloom · 45 days
Savoyed, richly flavored, holds off bolting a bit longer than plain types.
Space
Hybrid · 39 days
Smooth leaf, fast, slow to bolt: the summer-shoulder spinach.
Giant Winter
Open-pollinated · 45 days
Sow in fall, harvest through winter under cover. Sweetest greens of the cold months.
Malabar (summer alternative)
Heat-loving vine used like spinach.
Growing spinach in containers
6 in deep pot; excellent for balcony gardens.
Nutrition
Iron, magnesium, folate (spinach); betalains (beet).
Common questions
Why is my spinach so bitter?
Heat and drought stress. Grow in fall for the sweetest crop.
Where these numbers come from
- USDA Plant Hardiness Zone Map (2023 revision). Zone assignment and the 30-year normals behind every cold-hardiness figure.
- NOAA NCEI 1991-2020 Climate Normals. Frost dates, growing-season length, and the probability bands on both.
- Cornell, UMN, and UC Davis Cooperative Extension crop guides. Spacing, days to maturity, soil pH targets, and per-plant yield ranges.
- USDA FSIS / FDA Produce Safety guidance. Wash, cure, and cold-storage handling numbers.
Ranges are regional guidance, not a promise for your yard. Your own logged results always override the published range.