Quick answer
Direct sow spinach into cool, fertile soil and keep it evenly moist. Thin plants to roughly 10–15cm for mature leaves, or grow closer for baby-leaf cutting. Make small sowings every few weeks in spring and again from late summer; heat and long days cause many cultivars to bolt.
Spinach is a short crop rather than an all-summer crop in many climates. It can be ready for baby leaves in about a month and mature leaves soon after, but timing depends on temperature and cultivar. When summer conditions become unsuitable, switch to a heat-tolerant leafy crop rather than forcing stressed spinach.
True spinach and its substitutes
True spinach is Spinacia oleracea. Perpetual spinach is a leaf beet, while New Zealand spinach and Malabar spinach are unrelated warm-season plants. These substitutes can fill a summer harvest gap, but their germination, spacing and flavour differ, so do not apply this page's schedule to them.
Spinach cultivars may have smooth, semi-savoyed or deeply savoyed leaves. Smooth leaves are easy to wash; savoyed types have a substantial texture. Choose bolt-resistant cultivars for lengthening days and hardy ones for autumn or protected winter crops.
Site, soil and temperature
Give spinach four to six hours of direct sun in cool weather. Light afternoon shade can slow drying and heat stress as the season warms. Deep shade reduces growth and leaves stay wet longer.
Use fertile, well-drained soil that retains moisture. The University of Minnesota Extension gives a preferred pH of 6.5–8.0 for spinach. Add mature compost if soil is low in organic matter, rake to a fine surface and remove competing weeds.
Spinach germinates and grows best in cool conditions. A spell of warmth, drought or increasing day length can trigger a central flower stalk. Once bolting begins, leaves become smaller and stronger tasting; extra watering will not reverse the plant's developmental change.
Sowing
Direct sow where plants will grow because spinach develops a taproot and matures quickly. Make a shallow drill, water dry soil before sowing and cover lightly. Keep the surface damp until seedlings establish.
Make small successions rather than one thick row. Thin promptly: crowding does not create more full-size leaves, and poor airflow favours downy mildew. Eat clean thinnings as baby leaves.
For autumn and winter harvest, sow a hardy cultivar late enough to avoid summer heat but early enough to establish before growth slows. Cloches, fleece or an unheated greenhouse can protect leaves, although ventilation remains important on mild days.
Spacing and containers
Allow about 10cm for smaller plants and 15cm for mature rosettes. Baby-leaf rows can be denser because the crop is cut young. Leave enough row space to weed and harvest without crushing leaves.
Spinach is well suited to containers. A trough at least 15–20cm deep and about 30cm wide can hold several plants; around 10 litres of compost is a useful minimum. Use a vessel that drains freely and place it where it will not overheat. Window boxes dry quickly, so check them often.
Watering and feeding
Keep soil consistently moist but not saturated. Water at the base early enough that leaves dry. Drought accelerates bolting and makes leaves coarser. Mulch lightly around established full-size plants if the season is dry.
Rich garden soil amended with compost may need no further feed for such a short crop. In reused container compost, apply a balanced liquid feed at the labelled rate if growth becomes pale and slow. Excess nitrogen can make leaves soft and does not compensate for low light.
Diagnosing common problems
| Symptom | Likely causes to investigate | First checks |
|---|---|---|
| Central stalk elongates | Bolting from heat, long days or drought | Weather, day length and cultivar |
| Pale, slow leaves | Low nitrogen, cold roots, waterlogging or shade | Drainage, light and soil fertility |
| Yellow angular patches | Downy mildew | Leaf undersides, humidity and crowding |
| Tunnels inside leaves | Leaf-miner larvae | Translucent mines and larvae |
| Seedlings disappear | Slugs, snails, birds or drying soil | Night inspection and surface moisture |
| Brown leaf edges | Drought, salt build-up or root damage | Moisture depth and feeding history |
Remove badly affected leaves and improve airflow. Use resistant cultivars and avoid repeated spinach-family crops where disease has persisted. Identify a pest before applying a control to edible foliage.
Harvest and handling
Pick the largest outer leaves while the centre remains intact, or cut a whole rosette a few centimetres above soil for possible regrowth. Baby-leaf crops can be cut with clean scissors when leaves are suitably sized. Harvest in cool conditions and cool leaves promptly.
Wash carefully because crinkled foliage holds soil. Discard slimy or diseased leaves. Fresh spinach stores only briefly, so harvest close to use; blanching and freezing is more suitable for a glut.
The RHS spinach guide provides a UK month-by-month schedule and emphasises succession sowing. Record which weeks actually produce good leaves in your garden.
Sources and review basis
- How to grow spinach — Royal Horticultural Society
- Growing spinach and Swiss chard — University of Minnesota Extension
Bolting response and cold tolerance vary substantially by cultivar.