Herb

Growing basil

Ocimum basilicum · Lamiaceae
By Hannah Price · Updated 12 November 2026

Basil calendar

Basil sowing, planting and harvest calendar (UK)
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sow indoors			Sow indoors in March	Sow indoors in April	Sow indoors in May	Sow indoors in June
Plant						Plant in June
Harvest						Harvest in June	Harvest in July	Harvest in August	Harvest in September
Prune						Prune in June	Prune in July	Prune in August	Prune in September

Timings suit lowland southern and central Britain and most of Ireland. In northern England and Scotland, or in a cold spot, start two to three weeks later in spring and finish earlier in autumn.

Overview

Basil is a tender annual from warm climates, and in Britain it behaves best in a greenhouse, porch or on a sunny windowsill, only going outdoors in the warmest weeks. Grow your own and you will have far more than a supermarket pot provides, with flavours you can't easily buy. Successional sowings give a steady supply right through summer.

Varieties to try

'Genovese' is the classic large-leaved Italian type for pesto and tomato salads. 'Sweet Thai' has purple stems and an aniseed note that suits curries and stir-fries. 'Dark Opal' and 'Purple Ruffles' add colour to pots. Greek or bush basil makes a neat, small-leaved dome that copes slightly better outdoors, and lemon basil is lovely with fish.

Soil and site

Best soil: Light, free-draining compost or soil; never cold and sodden.

Warmth and light matter more than soil. Use a free-draining peat-free compost with some grit or perlite mixed in. Outdoors, choose the most sheltered sunny spot, perhaps against a south-facing wall or beside tomatoes in a growbag. Nights below about 10°C check growth, and frost kills plants outright.

Sowing and planting

Sow on a warm windowsill or heated propagator from March onwards, but April and May sowings in rising temperatures often catch up quickly. Scatter seed on moist compost, cover lightly and keep at around 20°C. Prick out seedlings into small pots once they have their first true leaves. Move plants outside only in mid-June after hardening off.

Spacing: Sow thinly on the surface and barely cover; space plants 20–30 cm apart in beds or grow three per 20 cm pot.

Care

Water sparingly and in the morning so leaves and compost dry before the cooler night, since wet roots after dark invite rot. Feed every couple of weeks with a dilute liquid feed. When plants reach about 15 cm, pinch out the growing tip just above a pair of leaves; side shoots follow. Remove flower buds as soon as they show.

Harvesting and storing

Pick from the top, nipping out whole tips rather than stripping lower leaves, which encourages branching. Basil blackens in the fridge, so keep cut stems in a glass of water on the worktop. To preserve a glut, blend leaves with oil and freeze in ice-cube trays, or make pesto and freeze in small tubs.

Common problems

Damping off collapses seedlings sown too thickly in cold, wet compost; sow thinly and use clean pots. Slugs and snails devour outdoor plants overnight, so keep them on raised tables. Under glass, glasshouse whitefly and aphids can build up; hang yellow sticky traps, rinse leaves and ventilate well.

Read more on the problems that most often hit basil:

Not sure what you're looking at? Try diagnosing it by symptom.

Month-by-month reminders

Jobs for basil come round in March, April, May, June, July, August and September. Each month page lists the rest of the garden's jobs for the same weeks.

Grow alongside

Sources

Names follow Kew's Plants of the World Online; timings and spacings reflect UK growing practice and were checked against the references below. Text is our own. See our editorial policy.