UK sowing calendar
When to sow basil in the UK
Basil sowing calendar (UK)
| Sow under cover | Feb-Apr |
|---|---|
| Sow / plant outdoors | Plant out/sow outdoors late May-Jun |
| Harvest | Jun-Sep |
Not hardy in the UK — grow it on a warm windowsill or in a greenhouse (sow under glass from Jan-early Apr, though Mar-Apr gives sturdier plants in better light). Only move it outside to a sunny, sheltered spot in early summer; sow small successional batches for a longer harvest.
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 basil.
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When to sow basil in the UK — FAQs
When should I sow basil in the UK?
Sow basil under cover Feb-Apr, then outdoors plant out/sow outdoors late may-jun. Not hardy in the UK — grow it on a warm windowsill or in a greenhouse (sow under glass from Jan-early Apr, though Mar-Apr gives sturdier plants in better light). Only move it outside to a sunny, sheltered spot in early summer; sow small successional batches for a longer harvest.
Can you sow basil outdoors in the UK?
Yes — sow or plant basil outdoors plant out/sow outdoors late may-jun. Wait until after the last frost (around mid-May, later in the north) for anything tender.
When is basil ready to harvest in the UK?
Basil is typically harvested Jun-Sep in the UK, depending on your sowing date, cultivar and region.
Is it too late to sow basil?
It depends on the month and your region. Basil has a UK outdoor window of plant out/sow outdoors 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.