When to sow Basil in the UK
Across the UK the first sowing of basil falls 11 weeks apart — late April in the mildest areas, mid July in the coldest. That gap is why a single national sowing date is wrong for almost everybody.
Sowing and harvest dates by region
Timings below are adjusted from the midlands and lowland wales baseline using Met Office average last and first frost dates for each area.
| Where you are | Sow indoors | Sow outdoors | Plant out | Harvest |
|---|---|---|---|---|
| South West Coast and Cornwall | late January to late May | early May to late May | early May to late May | late May to late August |
| South Coast and Channel | early February to early June | early May to late May | early May to late May | late May to late August |
| Greater London (Urban Heat Island) | late January to late May | early May to late May | early May to late May | late May to late August |
| South East and Home Counties | late February to mid June | late May to mid June | late May to mid June | mid June to mid September |
| East Anglia | late February to late June | late May to mid June | late May to mid June | mid June to mid September |
| Midlands and Lowland Wales | early March to early July | early June to late June | early June to late June | late June to late September |
| Wales and West Coast | late February to mid June | late May to mid June | late May to mid June | mid June to mid September |
| Northern England | mid March to mid July | mid June to early July | mid June to early July | early July to early October |
| Scotland Lowlands and Central Belt | late March to mid July | mid June to mid July | mid June to mid July | mid July to early October |
| Scotland Highlands and Islands | mid April to early August | mid July to early August | mid July to early August | early August to late October |
| Northern Ireland | late February to late June | late May to mid June | late May to mid June | mid June to mid September |
| Channel Islands and Isle of Man | late January to late May | late April to mid May | late April to mid May | mid May to mid August |
About the earliest indoor dates
The indoor sowing dates shift with your local last frost, because that is what decides when the seedling can go outside. Under glass, though, the limiting factor is daylight rather than frost. In the mildest regions the table pulls this sowing back into midwinter, and a UK windowsill in January has neither the light nor the day length to raise a sturdy plant — you get pale, drawn seedlings that never catch up. Unless you are growing under supplementary lighting, treat mid February as the practical earliest sowing for basil however mild your area.
Growing notes
Basil is not hardy in the UK: sow indoors from March to July and only plant out in early summer once nights stay above 10C, or keep it on a windowsill or in a greenhouse. Sowing a few small batches indoors a few weeks apart works better than treating it as an outdoor succession crop.
At a glance
- Spacing
- 15 cm between plants
- Row spacing
- 20 cm
- Plants per m²
- 25
- Days to maturity
- 60 days
- Yield per plant
- 0.15 kg
- Sun
- Full sun
- Frost tender
- Yes — do not plant out until after the last frost
- Grows in a container
- Yes, 10 litres or more
- Minimum soil depth
- 20 cm
- Balcony rating
- 5 out of 5
What usually goes wrong
- aphids
- damping off
- grey mould
- powdery mildew
- slugs
Companion planting
Grows well near
Related guides
Timings cross-checked against RHS guidance for basil.