Spinach is one of the fastest leafy crops you can grow: sow it, and within weeks you are picking tender leaves for salads and cooking. It is also one of the most nutritious vegetables in the garden, and freshly picked spinach — sweet, tender and deep green — is nothing like the limp bags from the shops.
Spinach is a cool-season crop that bolts at the first sign of heat, so the trick is to sow it early, sow it late, and sow it often.
Spinach at a glance
| Growing factor | What spinach need |
|---|---|
| Sun | full sun |
| Soil pH | 6.0–7.5 |
| Days to germination | 7–14 |
| Days to maturity | 40–50 |
| Spacing | 4–6 inches |
| Water needs | moderate |
| Cold tolerance | hardy |
| Family | Amaranthaceae |
Starting seeds
This is a direct-sow crop: the seed goes straight into the garden where it is to grow, and the plants are not transplanted. Prepare a fine, weed-free seed bed, sow at the depth shown on the seed packet, and keep the bed evenly moist until seedlings appear — expect germination in 7–14 days.
Sow too early into cold, wet soil and germination stalls; sow too late and the plants run out of season. Use our frost-date calculator and the hardiness-zone finder to place your sowing window. Zones 11–13 are frost-free, so sowing windows there are set by heat and rain rather than frost — check your local extension service.
Spinach is sown direct where it is to grow — it dislikes transplanting. Sow thinly in shallow drills and thin seedlings to their proper spacing so each plant has room to form good leaves. Sow little and often for a steady supply, and sow in partial shade in late spring so the plants stay cool for longer. Seed sown into warm, dry soil germinates poorly, so keep the seed bed moist.
Transplanting and planting out
Spinach is not usually transplanted, though you can start a few plants in modules if you want an early crop — handle them gently, as the roots dislike disturbance. The main job after sowing is thinning: thin seedlings to their proper spacing so the leaves have room to grow, and keep the bed weed-free and moist.
Space plants 4–6 inches apart — crowding is one of the commonest causes of small harvests. Our plant-spacing calculator works out how many plants fit your bed.
Soil and feeding
Spinach grow best in rich, well-drained soil with plenty of organic matter. Dig in compost before planting: it improves heavy soil, helps light soil hold moisture, and feeds the soil life that feeds your plants. Aim for a soil pH of 6.0–7.5 — a simple soil test will tell you where you stand, and garden lime or sulfur can nudge pH up or down over a season, so test before you amend rather than guessing.
Feed lightly and steadily rather than in one heavy dose: too much fast nitrogen late in the season pushes leafy growth at the expense of the part you eat. Our fertiliser calculator works out amounts for your bed size, and the soil-volume calculator tells you how much mix a new bed needs.
Watering
Water needs are moderate: keep the soil evenly moist, watering deeply when the top inch or two dries out. Deep, infrequent watering builds deeper roots than a daily sprinkle.
Water at the base of the plant, in the morning, so the leaves dry quickly and the water reaches the roots. Our watering calculator gives a starting point for your bed size, and the watering schedule generator can build a routine around it. A mulch layer cuts evaporation and keeps moisture even.
Sunlight and temperature
Spinach need full sun — a spot that gets sun for most of the day. Our sunlight calculator can check your spot.
This crop is rated hardy for cold tolerance, so it stands up to frost and even light freezes, and it is at its best in the cool seasons. In Zones 11–13, which are frost-free, heat rather than cold is the limit — grow it in the cooler months, with afternoon shade in the hottest weather. Our hardiness-zone finder will confirm your zone, and the frost-date calculator gives you the frost dates to plan around.
Pests and diseases
The pests and diseases most often reported on spinach are aphids, slugs, cutworms. Healthy, well-watered plants resist attack better than stressed ones, and rotating beds so the Amaranthaceae family does not repeat in the same spot helps keep soil-borne problems down.
- Aphids — small sap-sucking insects on new growth; wash off with a strong jet of water and encourage ladybirds.
- Slugs — chew ragged holes in leaves at night; water in the morning so the surface dries by evening.
- Cutworms — caterpillars that chew through young stems at soil level; a cardboard collar around each stem protects it.
Inspect plants weekly, especially leaf undersides, and act early. Our pest-identifier helper can help identify what you are seeing.
Companion plants
Good companion plants for spinach include:
- Marigolds — their roots discourage some soil pests
- Basil — attracts pollinators
- Onions — their scent is said to confuse pests
- Lettuce — shallow-rooted, fills gaps without competing
Our companion-planting finder can suggest more pairings for your bed plan.
Harvesting
Pick spinach leaves when they are young and tender, starting with the outer leaves and letting the centre keep growing — a plant picked this way can give several pickings. Pick in the morning when the leaves are cool and crisp, and use them the same day. Once a plant starts to bolt, pick the remaining leaves quickly and pull the plant, since bolted spinach turns bitter.
Expect the crop to be ready about 40–50 days after sowing, though weather and variety shift that window by a week or two either way. Our harvest-date calculator works out your expected harvest date from your sowing date, and the vegetable-yield estimator can estimate how much a bed should produce.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| Plants bolting to seed | hot weather or long days | Spinach bolts fast in heat, so sow it for spring and autumn and give summer sowings afternoon shade. |
| Poor germination | warm, dry soil | Spinach seed germinates best in cool, moist soil. |
| Slugs eating young leaves | damp, sheltered conditions | Water in the morning so the surface dries by evening, keep the bed tidy, and protect young plants until they are established.. |
Plants bolting to seed
Spinach bolts fast in heat, so sow it for spring and autumn and give summer sowings afternoon shade.
Poor germination
Spinach seed germinates best in cool, moist soil.
Slugs eating young leaves
Water in the morning so the surface dries by evening, keep the bed tidy, and protect young plants until they are established..
Frequently asked questions
When should I plant spinach?
Sow once the soil is workable in spring — this crop is rated hardy for cold tolerance, so it can go in early. For zone-specific timing, see zone 3 or zone 6, and check your local extension service for the dates that fit your area.
How long do spinach take to grow?
Spinach take 40–50 days from sowing to maturity, and seed germinates in 7–14 days. Weather and variety shift the harvest window by a week or two, so judge readiness by look and feel rather than the calendar alone.
How far apart should I plant spinach?
Space plants 4–6 inches apart — that is the room a mature plant needs, and crowding means poor airflow and small harvests. Our plant-spacing calculator works out how many fit your bed.
Can I grow spinach in summer?
It is difficult but possible: sow in partial shade, keep the soil consistently moist, and choose a slow-bolting variety. Even so, summer spinach bolts quickly.