UK sowing calendar
When to sow summer squash in the UK
Summer squash sowing calendar (UK)
| Sow under cover | Apr-May |
|---|---|
| Sow / plant outdoors | Direct sow late May-Jun |
| Harvest | Jul-Oct |
Same tender cucurbit timing as courgettes — sow under cover in April/early May or direct sow after the last frost (late May-Jun). Fruits crop from mid-summer to the first frost; harvest young with soft skin for best flavour.
UK timing runs on the last-frost date, not a USDA zone. Most of Britain sees its last frost around mid-May, with the north and exposed inland gardens a week or two later and the mild south-west and coast earlier. Tender crops start under cover and only go out once frost has passed; hardy crops can be direct-sown as soon as the soil is workable.
Timing aligned with the RHS grow-your-own guide for summer squash.
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When to sow summer squash in the UK — FAQs
When should I sow summer squash in the UK?
Sow summer squash under cover Apr-May, then outdoors direct sow late may-jun. Same tender cucurbit timing as courgettes — sow under cover in April/early May or direct sow after the last frost (late May-Jun). Fruits crop from mid-summer to the first frost; harvest young with soft skin for best flavour.
Can you sow summer squash outdoors in the UK?
Yes — sow or plant summer squash outdoors direct sow late may-jun. Wait until after the last frost (around mid-May, later in the north) for anything tender.
When is summer squash ready to harvest in the UK?
Summer squash is typically harvested Jul-Oct in the UK, depending on your sowing date, cultivar and region.
Is it too late to sow summer squash?
It depends on the month and your region. Summer squash has a UK outdoor window of direct sow late may-jun; northern and exposed gardens run a week or two behind the south. Open Growli and tell it your postcode for timing tuned to your own last-frost date.