How to grow basil
Everything you need to know about growing fragrant basil, in our detailed Grow Guide.
Basil is a versatile annual herb used in pasta sauces, pizzas, salads and Thai curries. It is a member of the Lamiaceae (mint) family. Sweet basil plants tend to dominate the supermarket shelves, but there are many other exciting types to try when you grow your own.
How to grow basil
Sow basil seed successionally from spring to summer so you have a continuous crop. Pot on into individual pots when plants are big enough to handle. Water sparingly as basil suffers when sitting in wet compost. Harvest leaves individually rather than chopping the plant with scissors, as this will enable new leaves to grow.
How to sow basil seed
Grow basil in well-drained, fertile soil in a warm, sheltered position out of direct midday sun. To get a quality crop that lasts from early spring to mid-autumn, it’s best to grow basil in a container.
Start your basil seeds off in pots of moist peat-free multi-purpose compost on a warm (around 20°C), bright windowsill out of direct sun. Water sparingly until germination, then water only when needed and in the mornings to avoid damping off. When seedlings are big enough to handle, pot them on into individual pots filled with a peat-free, soil-based compost. Pinch out tips to encourage bushy plants.
Keep potted basil plants indoors or plant outside in warmer locations, in the ground or a container, in a sunny sheltered spot, from June to August. To acclimatise plants to conditions outdoors, stand them outside in a sheltered, lightly-shaded spot during the day, and bring the basil pots back in at night. Do this daily for about two weeks.
More like this
Watch Monty Don plant out basil with tomato plants, in this clip from BBC Gardeners' World:
Did you know...
In Elizabethan times, sweet basil leaf was dried and used as a snuff to treat headaches and colds. It is also seen as a sacred plant – some Greek Orthodox churches use Greek basil to prepare their holy water and, at Hindu weddings, the parents of the bride traditionally present the groom with a basil leaf.
How to care for basil plants
When growing basil, one of the most important things to remember is to water – if the soil becomes too dry, they'll quickly wilt. Don't let the plants sit in water though, as this can cause the roots to rot.
Outdoors, basil plants need protection from wind and frost. Always water with care, ideally before midday, and avoid splashing the leaves. This should help prevent botrytis (powdery mould).
Plants will grow quickly in containers, so expect to pot them up a few times during the growing season. When basil flowers, it affects leaf quality. To avoid basil plants flowering, remove any flower stems as soon as possible. Towards the end of the season you could let some basil flowers bloom, to provide nectar for bees and butterflies.
Basil is a half-hardy annual, so new plants will be needed each year. However, in autumn, when temperatures start to dip, bring a few plants back indoors to provide a fresh supply of leaves over winter.
How to grow supermarket basil
Most fresh basil sold in supermarkets is sweet basil. It takes just 22 days from seed to sale, so the rootball is underdeveloped. This is why it normally dies if you plant it in the garden. If you want to keep your basil plants alive, tip the plants out of their pot and tease their roots apart to separate them. Replant individually into pots of soil-based compost. Keep them moist but not wet, and place them somewhere warm but not in direct sun. When you see roots through the drainage holes in the pot base, harden off and plant out in the garden.
Pests and diseases
Protect plants from snails and slugs. Basil is also prone to attack by whitefly and red spider mite. It can also be susceptible to grey mould and powdery mildew, so ensure that plants grown in a greenhouse have good ventilation around them.
How to harvest basil
Pick the leaves and tops of basil regularly throughout the summer. You can be quite ruthless, as long as you leave at least three pairs of side shoots so your plants can regrow. Don’t wash the leaves until you’re ready to use them as they’ll turn slimy.
Preparing and using basil
Aromatic basil is a key ingredient in the kitchen and can be used in salads, pesto, pasta sauces and Thai curries. Basil plant is attractive, well-suited to growing in containers, and is said to deter whitefly - try growing it next to tomatoes.
Eat leaves raw and as fresh as possible. Here are our tips on how to pick herbs to ensure they don't run to seed and cut short your harvests. For the best flavour, add fresh basil at the end of cooking. It’s said that you should tear rather than chop basil leaves to release their wonderful aroma. Use in salads, soups, stews, to make pesto and other sauces, particularly any recipe containing tomatoes. And when the evenings become colder in autumn, bring your plants indoors to a warm, bright place to continue picking them.
Here, Monty Don demonstrates how to make pesto using fresh basil from the garden:
Basil is best used fresh. It is difficult to dry or freeze well. You can stand cut stems in a glass of water in a cool spot for a few days ready to use, providing the water is changed every day.
Advice on buying basil
- Basil seeds are available from a number of online seed companies or you should be able to buy seed packets in garden centres and your local allotment shop
- You can buy basil plants, but growing from seed is easy and gives you a wider choice of varieties
- If you want to grow several varieties, you could share seed packets between friends or grow one or two varieties each and then swap seedlings once they are growing on strongly
Where to buy basil online
Basil varieties to grow
Basil 'Sweet' (Genovese), Ocimum basilicum, is the most popular variety of basil, with large, soft leaves and a sweet taste. It's great raw with tomatoes and is widely grown in Italy for use in pesto.
Basil 'Crimson King'
Ocimum basilicum 'Crimson King' is a British-bred, purple-leaved variety with uniform, 'cupped' leaves and greater vigour than other purple varieties. The unusual colour of this basil plant means it looks great in containers or window boxes, combined with other plants - try this tomato, basil and calendula pot.
Greek or 'bush' basil (Ocimum basilicum var. minimum 'Greek') has smaller leaves than sweet basil, with a slightly sweeter, anise-clove flavour. Use them to make pesto or add to tomato sauces or pizzas. Its neat, compact shape makes it ideal for a container.
Basil 'African Blue'
Ocimum basilicum 'African Blue' has attractive purple-blue flowers (much-loved by bees) and purple-veined leaves. It's larger than other basils, reaching 75cm, and looks great in a pot or in a border. This basil plant is a tender perennial so will need protection over winter.
Ocimum tenuiflorum, also known as sacred or holy basil, or 'tulsi', is a small variety with purple-green serrated leaves and purple stems. It originates in Thailand and therefore is the perfect basil to use in Thai dishes.
Ocimum basilicum ‘Cinnamon’ has spikes of mauve flowers and purple-veined leaves with a very spicy cinnamon flavour and hints of cloves. Good for stir-fries.
Basil 'Red Rubin'
Ocimum basilicum var. purpurascens ‘Red Rubin’ produces highly aromatic, deep purple leaves and mauve-pink flowers. Suitable for ornamental and herb beds. Grows to 45cm.