Winter Squash
Butternut Squash, Acorn Squash, Delicata, Spaghetti Squash, Kabocha
Needs a long season — start 3–4 weeks early indoors in short-season climates. Vines can spread 6–10 ft; allow space or train onto trellis. Cure after harvest (10–14 days at 80–85°F) for long storage. Leave 1" stem attached when cutting to prevent rot.
- Germination
- 4–10 days
- Soil temperature
- 16–35 °C
- Harvest after sowing
- 85–110 days
- Spacing
- 90–150 cm
When to plant winter squash
Sow outdoors 1–2 weeks after your last spring frost.
Dashed line: typical last spring frost in zone 7 (Apr 5). Zone dates are averages; most of the UK is zone 8–9, central Europe 6–7 and the Baltics and Scandinavia 4–6. In the app, Tomatograph uses your garden's own frost dates.
How to grow winter squash
- 1
Check your season
Winter squash needs 85–110 frost-free days. Count back from your first autumn frost; in short summers start seeds in pots 3–4 weeks early.
- 2
Sow
Sow 2–3 seeds 2.5 cm deep per hill in fertile, well-drained soil 1–2 weeks after the last frost, and thin to the strongest. Vines run 2–3 m, so give them room or a sturdy trellis.
- 3
Grow on
Water deeply at the base and keep weeds down until the leaves shade the ground. Slip straw under developing fruit to keep it off wet soil.
- 4
Harvest and cure
Cut when the skin is hard and evenly coloured and the stem has dried, leaving 2–3 cm of stem. Cure 10–14 days somewhere warm before storing.
Growing conditions
Light
Full sun
Water
Medium water
Temperature
15–32 °C
Frost tolerance
Frost-sensitive — protect below 0 °C
Days to maturity
75–110 days
Plant spacing
90 cm
How Tomatograph watches your winter squash
Tomatograph checks your local forecast every morning and only speaks up when one of these applies to your garden.
- Forecast of 2 °C or lowerFrost alert the evening before: cover plants with fleece or bring pots inside.
- 3 days at 35 °C or aboveHeat-wave alert while plants are flowering or fruiting: shade and water early.
- Humidity above 80% for 48 hoursCheck for powdery mildew, which thrives in those conditions.
- Within a week of maturityHarvest-window reminder based on when you planted.
Winter Squash questions
- When should I plant winter squash?
- Sow outdoors 1–2 weeks after your last spring frost.
- How long do winter squash seeds take to germinate?
- Usually 4–10 days at a soil temperature of 16–35 °C.
- How long until I can harvest winter squash?
- About 85–110 days after sowing, depending on variety and weather.
- How far apart should I plant winter squash?
- Allow 90–150 cm between plants.
- What grows well with winter squash?
- Good neighbours include corn, pea, nasturtium.
Growing guide written by Tomatograph. Planting figures from openplantdb (CC0 1.0). Zone frost dates are averages from openplantdb (CC0 1.0).