Basil
This genus is markedly more cold-sensitive than the other kitchen herbs in this KB (thyme, parsley, coriander) — treat it as a warm-season annual only, and don't rush it outdoors before nights are reliably mild.
Care
Needs warmth as well as light; a sheltered spot or a sunny windowsill/greenhouse gives the best results.
Water the compost, not the leaves, and avoid letting it sit wet overnight — a common cause of collapse.
Peat-free, well-drained compost; doesn't like heavy, wet soil.
Pinch out the growing tips regularly from an early stage, and remove flower spikes as soon as they appear — flowering makes the leaves turn bitter and slows new leaf production.
A weak balanced feed every two or three weeks for a plant in a pot, and nothing in the ground on decent soil. Overfeeding gives large, watery leaves with noticeably less aroma — the flavour is concentrated in a plant grown slightly hard.
Cuttings root in a glass of water within a week or two, which is why a supermarket pot can be turned into several proper plants. Seed sown in warmth in spring is the other route; basil needs heat to germinate.
Month by month
Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.
- MaySow or plant out only once all frost risk has passed and nights are reliably mild — this genus is very cold-sensitive, more so than most other kitchen herbs. how ›
- JunePinch out growing tips regularly to encourage bushy growth and delay flowering. how ›
- JulyRemove any flower spikes as soon as they appear to keep leaf production going and prevent bitterness. how ›
Months based on climate: UK. Your choice stays on this device.
- AprilSow or plant out only once all frost risk has passed and nights are reliably mild — this genus is very cold-sensitive, more so than most other kitchen herbs. how ›
- JunePinch out growing tips regularly to encourage bushy growth and delay flowering. how ›
- JulyRemove any flower spikes as soon as they appear to keep leaf production going and prevent bitterness. how ›
Months based on climate: Northern Italy. Your choice stays on this device.
- AprilSow or plant out only once all frost risk has passed and nights are reliably mild — this genus is very cold-sensitive, more so than most other kitchen herbs. how ›
- JunePinch out growing tips regularly to encourage bushy growth and delay flowering. how ›
- JulyRemove any flower spikes as soon as they appear to keep leaf production going and prevent bitterness. how ›
Months based on climate: Central Italy. Your choice stays on this device.
- MarchSow or plant out only once all frost risk has passed and nights are reliably mild — this genus is very cold-sensitive, more so than most other kitchen herbs. how ›
- JunePinch out growing tips regularly to encourage bushy growth and delay flowering. how ›
- JulyRemove any flower spikes as soon as they appear to keep leaf production going and prevent bitterness. how ›
Months based on climate: Southern Italy and islands. Your choice stays on this device.
Common problems
How to spot it. A healthy-looking plant wilts and dies within days, especially if compost has been kept wet or the plant has been in a cold, damp spot.
What to do. Almost always overwatering or cold — let the compost dry slightly between waterings and keep this genus warmer than most other herbs; there's usually no recovering an affected plant.
How to spot it. Flavour turns harsh or bitter, usually alongside flower spikes appearing.
What to do. Pinch out flower spikes promptly and harvest leaves regularly — this delays flowering and keeps the flavour sweet.
How to spot it. On soft new growth, especially indoors.
What to do. Rinse off with water or wipe leaves; avoid chemical sprays on a plant grown for eating.
Questions
Basil: is it hardy?
H1c: Tender, needs above 5°C. It survives above 5 °C.
Can it grow in a pot?
One of the best herbs for a pot or windowsill, since it needs the warmth a container position on a sill or patio provides more reliably than open ground.
Basil: when do you prune it?
Pinch out the growing tips regularly from an early stage, and remove flower spikes as soon as they appear — flowering makes the leaves turn bitter and slows new leaf production. In the calendar for UK, pruning falls in June–July.
Basil: when does it flower?
In the climate of UK it flowers in July–August.
When do you feed it?
A weak balanced feed every two or three weeks for a plant in a pot, and nothing in the ground on decent soil. Overfeeding gives large, watery leaves with noticeably less aroma — the flavour is concentrated in a plant grown slightly hard. Feeding months, UK: June–July.