Sweet Basil

How to grow Sweet Basil

Written by the GardenDecoded editorial team · Last reviewed 21 July 2026 · Written for UK gardens · How we research our guidance

Planting

Sow indoors from March onwards at around 18-20C, or buy plants. In most of the UK basil does noticeably better in a greenhouse, conservatory or on a warm windowsill than outdoors. If planting outside, wait until well after the last frost and choose the warmest, most sheltered spot you have.

Pruning

Pinch out the growing tip once the plant has three or four pairs of leaves, and keep pinching above a leaf pair as you harvest. Remove flower buds as they appear — once basil flowers the leaves become smaller and coarser and the plant starts to shut down.

Propagation

From seed, sown thinly and barely covered. Softwood cuttings root quickly in water on a windowsill, which is a useful way to keep a supermarket pot going.

Pests and diseases

Slugs and snails will strip young plants outdoors. Under cover, watch for aphids and whitefly. Grey mould and stem rot follow overwatering and cold, damp compost, which is by far the commonest way basil is lost.

Notes

Treat as an annual — it will not survive a UK winter outdoors. Supermarket pots contain many seedlings crammed together; splitting them into two or three smaller pots gives much longer-lived plants.

This guidance was researched and written by GardenDecoded — see our editorial policy for how guides are checked and reviewed.

Other names for this plant

These names have all been used for Ocimum basilicum but are no longer the accepted name. You may still meet them on old labels, in books, or in nursery catalogues.

Others in Ocimum