Growli

UK sowing calendar

When to sow sweetcorn in the UK

Sweetcorn sowing calendar (UK)

Sow under coverApr-May
Sow / plant outdoorsDirect sow late May-Jun
HarvestAug-Oct

Tender — sow under cover in mid-spring or direct sow outdoors only after the last frost (late May-Jun); northern and cold gardens should start it indoors. Plant in blocks rather than rows for wind pollination, and give it a warm, sunny site so the cobs ripen.

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 sweetcorn.

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When to sow sweetcorn in the UK — FAQs

When should I sow sweetcorn in the UK?

Sow sweetcorn under cover Apr-May, then outdoors direct sow late may-jun. Tender — sow under cover in mid-spring or direct sow outdoors only after the last frost (late May-Jun); northern and cold gardens should start it indoors. Plant in blocks rather than rows for wind pollination, and give it a warm, sunny site so the cobs ripen.

Can you sow sweetcorn outdoors in the UK?

Yes — sow or plant sweetcorn outdoors direct sow late may-jun. Wait until after the last frost (around mid-May, later in the north) for anything tender.

When is sweetcorn ready to harvest in the UK?

Sweetcorn is typically harvested Aug-Oct in the UK, depending on your sowing date, cultivar and region.

Is it too late to sow sweetcorn?

It depends on the month and your region. Sweetcorn 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.