Vegetable · Amaranthaceae
When to plant spinach
True spinach, Spinacia oleracea, is a cool-season leaf crop. The RHS describes mild conditions around 15–20°C as ideal; hot, dry weather can bring premature flowering and end useful leaf harvests.
Sow direct
6 weeks before
Counted from your last spring frost.
Days to maturity (estimate)
40-50
From sowing to first harvest; cultivar and conditions matter.
Frost tolerance
Hardy
How much cold the plant itself will take.
Choose a place for estimated dates and local climate checks.
Timing, in frost-relative terms
These offsets are the starting assumptions used by our calendar for spinach. They do not establish suitability in every climate. Your seed packet, cultivar and local growing advice take priority; in frost-free places the calendar uses monthly temperature patterns instead.
- Sow direct 6 weeks before the last frost.
- Expect 40–50 days to maturity, counted from sowing.
- Sow again every 14 days for a continuous supply.
- Can also be sown in late summer for an autumn crop or to overwinter.
Getting the timing right
Keep the seedbed moist and make small, repeated sowings. A short row harvested regularly is often more useful than many plants reaching their best size together.
Frost tolerance
Check the named variety and local forecast before exposing young growth. The catalog cold-damage figure is a reference, not a guarantee: plant age, acclimatisation, wind and the duration of a freeze affect damage.
Classified as hardy, with a catalog cold-damage reference of -9°C (15.8°F)15.8°F (-9°C). Exposure duration, growth stage and acclimatisation change cold tolerance.
Before you plant spinach
Use the calendar to plan ahead, then check the conditions in your own garden.
- Measure the soil at sowing depth. Aim for at least 4.5°C (40.1°F); the calendar estimates soil warmth from air temperatures and cannot measure your bed.
- Frost tolerance does not make saturated or frozen soil suitable for planting. Wait until the bed can be worked without smearing or compacting it.
- Use the maturity range on your seed packet when choosing a variety. Cold, short days and transplant stress can make harvest later than the calendar estimate.
Grow true spinach in the cooler part of your season
Keep the seedbed moist and make small, repeated sowings. A short row harvested regularly is often more useful than many plants reaching their best size together.
Choose bolt-resistant varieties for warmer sowings and hardy varieties for overwintering. Light shade can help in warm conditions, but it does not turn extreme summer heat into a suitable season.
Malabar spinach, New Zealand spinach and perpetual spinach are different plants. They can be useful alternatives, but their timing and growth habits should not be copied from this true-spinach calendar.
Growing in a container
Spinach suits containers with moisture-retentive compost and drainage. Check pots frequently during dry weather.
Further reading: RHS spinach growing guide . General crop guidance; local dates on this site are calculated separately. Source checked 18 September 2026 by Safe to Plant; this is not an expert review.
How the dates are calculated and their limits · Keep a growing record · Report a local discrepancy