Basil
Ocimum basilicum · Annual
The most popular herb to grow indoors, and one of the most forgiving. Basil wants warmth and a lot of light. Get those two right and the rest looks after itself.
What it needs indoors
- Light
- Full sun6–8 hours direct sun
- Water
- Keep moistWhen the top of the soil feels dry
- Temperature
- Above 70°F
- Growing medium
- Light potting soil or coconut coir
- Native range
- Tropical India and Southeast Asia
- Difficulty
- Beginner
What usually goes wrong
Black blotches on the leaves a day or two after a cold night
Chilling injury. Basil comes out of the tropics and has no cold response to fall back on, so a windowsill sitting at 45°F behind the glass at three in the morning damages tissue even if the room is warm again by breakfast.
Fix: Move the pot off the sill overnight, or slide a folded towel between the pot and the cold glass. Marked leaves will not recover, so pinch them off and let the plant push new growth.
Long bare stem between each pair of leaves
The plant is reaching for a brighter spot it cannot find.
Fix: South-facing window, or a grow light 6 to 8 inches above the plant for around 12 hours. Pinch the stretched tips back to the lowest healthy pair of leaves and the regrowth comes back tighter.
A flower spike pushes out of the top of the plant
Basil is an annual and flowering is the end of its programme. Leaf production slows once the spike forms and the flavour goes thin and soapy on the way.
Fix: Pinch the spike out the moment you spot it, along with the pair of leaves under it. Harvest by taking growing tips rather than stripping leaves off the sides, and the plant stays in leaf mode for months.
Guides that mention basil
Wants the same conditions
Grow these alongside basil and one watering routine will suit them all.