How to grow Basil

Ocimum basilicum · sweet basil

An aromatic, frost-tender herb grown for its leaves. It needs warmth and sun and goes outdoors only once nights stay above 10 °C.

Quick facts

Type	Herb
Family	Lamiaceae
Light	Full sun
Soil pH	6–7.5
Frost	does not tolerate frost
Soil for sowing	from 18 °C
Germination	8 days
Seedlings ready	30 days
Sowing to harvest	55 days
Where it grows	Greenhouse, Open ground, At home

When to plant

Sow for seedlings about 5 weeks before planting out.

Plant out in open ground about a week after your last spring frost, once the soil is warm.

In an unheated greenhouse everything moves about three weeks earlier.

The first harvest comes about 55 days after the shoots appear.

Frost dates · When to plant

Care

Greenhouse

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	18…27 °C	—
Growth	every 3 days	10…26 °C	nitrogen, 14 days into the stage
Harvest	every 2 days	10…26 °C	nitrogen, 10 days into the stage

Open ground

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	18…27 °C	—
Growth	every 4 days	10…26 °C	nitrogen, 14 days into the stage
Harvest	every 3 days	10…26 °C	nitrogen, 10 days into the stage

At home

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	18…27 °C	—
Growth	every 2 days	10…26 °C	balanced (NPK), at the start of the stage; balanced (NPK), 14 days into the stage
Harvest	every 2 days	10…26 °C	balanced (NPK), at the start of the stage; balanced (NPK), 14 days into the stage

Growing notes

Light

Needs full sun, at least 6 hours of direct light a day; sun-grown basil has more flavour.

Soil

Warm, fertile, moist but well-drained soil, pH 6–7.5.

Care

Keep the soil evenly moist, about 38 mm of water a week, and water in the morning at the base of the plant. Feed lightly — a little nitrogen every 2–3 weeks in beds, a balanced liquid feed in pots — because heavy feeding weakens the flavour. Start picking when plants have 6–8 leaves, pinch out the shoot tips to keep them bushy and remove flower buds as soon as they appear.

Pests and diseases of Basil

Sources

Figures checked against these sources.