Crop profile

Spinach crop profile

A cool-season leafy crop, best grown in fertile beds and harvested gradually while plants are tender.

Italiano

Starting method

Direct sowing

Direct soil

4 °C

Transplant soil

not available

Night minimum

0 °C

Frost buffer

-20 days

Heat stop

26 °C

Harvest

35–55 days

Indoor lead

not available

Key temperatures

0
5
10
15
20
25
30
35
40 °C

Below 4 °CCold risk: slower growth or cold damage.
4 °CMinimum threshold to start direct sowing: 4 °C.
4–21 °CBest range for growth and production.
21–26 °CPerformance drops and plants move into stress.
Above 26 °CPause transplants: heat stress risk.

Spinach cycle

1. Start
Method:
direct sowing
2. Direct sowing
Soil: at least 4 °C
Night minimum: at least 0 °C
3. Growth
Ideal temperatures 4–21 °C
Avoid peaks above 26 °C
4. Harvest
First harvest around:
35–55 days after sowing

How to start

Recommended method: direct sowing.
Prepare the bed when soil and nights are stable.
Sow when soil has reached at least 4 °C and nights stay above 0 °C.

Temperatures to respect

Direct-sowing soil: minimum 4 °C.
Night minimum: minimum 0 °C.
Heat stop: 26 °C.
Suggested frost buffer: -20 days.

Harvest timing

Cycle to first harvest: about 35–55 days.
Harvest gradually as produce reaches maturity.

Seasonal notes

Protect young plants from late frosts and thermal swings.
In summer, avoid water stress and heat peaks above 26 °C.
Steady growth improves development and harvest quality.

FAQ and sources

When should you sow spinach?

Sow spinach directly in cool soil, from about 4 °C, with nights close to 0 °C. It is ideal for spring and autumn, not peak heat. You can sow before the last frost because it tolerates light cold, but avoid soggy, compacted soil. The cycle is quick: 35-55 days for the main harvest. Sow successively so everything does not mature at once, and choose varieties suited to the season.

Why does spinach bolt?

Spinach bolts with heat, drought, and long days. It grows best in mild, cool temperatures; above about 26 °C the risk of bolting rises strongly. Once it starts making a flower stem, the leaves become smaller and less pleasant. To avoid this, sow early in spring or from late summer, keep soil moist, and use light shade for late sowings. In full summer it is often better to pause and restart in autumn.

How do you harvest spinach so it regrows?

For repeat harvests, take the outer leaves and leave the heart of the plant intact. Alternatively, cut young plants a few centimetres above the crown; if they are not stressed, they can make new leaves. Do not wait for huge leaves: spinach is more tender and sweet when picked young. After each cut, water moderately, especially in dry weather. If you see the plant stretching into a stem, harvest what you can immediately.

Does spinach grow in pots?

Yes. Spinach grows well in pots if the container is wide enough and does not dry out too much. Use fertile compost, sow broadcast or in shallow rows, and thin to leave air between plants. The pot should be in sun in spring and autumn, but in a cooler position if sudden heat arrives. Water is decisive: dry soil means tough leaves and bolting. Avoid heavy nitrogen feeds close to harvest.

Can spinach be grown in autumn and winter?

Yes. Spinach is one of the best autumn crops. If sown in time, it forms a rosette before cold weather and then keeps growing slowly. In mild areas you can harvest for much of winter; where frost is strong, protect it with a tunnel or fleece. Autumn sowings have an advantage: less heat and less bolting. Avoid waterlogging, because roots suffer in cold wet soil. A raised bed helps a lot.