How to grow borage

Borage is an edible herb, and the attractive blooms are a popular garnish to summer drinks, particularly Pimms. The young leaves have a cool cucumber flavour and are ideal to add to salads and salad dressings. Borage thrives in a sunny spot and needs a well-drained soil. Because the flowers are so attractive to bees, it's a useful plant to grow alongside fruit and vegetables to entice more insects to pollinate crops.

Borage is often one of the latest annuals to bloom, right up until the first frosts.

Bear in mind that borage leaves are hairy and can cause contact dermatitis in people with sensitive skin, so it's a good idea to wear gloves when handling borage plants. Don't consume the plant regularly or in quantity without consulting a doctor or qualified herbalist.

How to grow borage

Borage is an annual, which means it completes its life cycle within one growing season. It grows readily from seed which can be sown directly in the ground – no special equipment required. Borage can be grown in a border of annual flowers or is an excellent gap-filler in any bare spots between established plants in a border.

Growing borage: jump links

• Planting borage
• Caring for borage
• Harvesting borage
• Growing borage: problem solving
• Buying borage
• Borage varieties to grow

More on growing borage:

• Carol Klein's favourite plants for wildlife
• Nectar and pollen throughout the year
• Ways to mix edible and ornamental plants

Where to grow borage

Sow the large black borage seeds directly where the plant is to flower, as it forms a deep root and doesn’t do well if transplanted. Choose a well-drained site that gets sun for at least half the day. If your ground is heavy and slow to drain, add fine gravel and mound up the soil, so water drains away more easily. Borage does best in soil low in fertility so there’s no need to add fertilizer or organic matter.

Although borage isn’t ideal for growing in containers, if this is the only option, then choose a large pot (at least 25 cm deep and over 30 cm wide), filled two-thirds with peat-free, general-purpose potting compost and one third coarse grit.

When to plant borage

Sow borage seed from mid spring, after the last frosts. A second sowing can be made in late spring. It's best to sow borage seed where you want it to grow, as it doesn't do well when transplanted.

Borage will self-seed if the faded flowers are left on the plant. Depending on your garden, this may be desirable in an informal border, but if seeding is likely to be a nuisance, deadhead spent blooms before the seed develops.

How to plant borage

Sow borage 5cm deep in moist soil, and thin the resulting seedlings to at least 30cm apart.

How to care for borage

Remove faded flower heads from borage plants to encourage more blooms to form. Once flowering has finished, simply dig up and compost borage plants – the mineral-rich leaves will help fertilise soils the following year. Do take off the seed heads before composting plants or you’ll end up with lots of borage seedlings all over the garden.

How to harvest and use borage

Borage flowers make an attractive garnish and add a refreshing flavour to cold drinks and salads. They can also be crystallised to use as cake decorations. Pick the flowers when they have just fully opened. The cucumber-flavoured leaves should be harvested when young and used fresh, in salads, soups and other savoury dishes, or to add flavour to salad dressings.

Medicinal uses of borage

Borage has been used as an herb since the time of the ancient Greeks and Romans. Recently, it's been found to be a rich source of GLA (gamma lineoleic acid), used to combat various cancers as well as pre-menstrual syndrome. Borage or starflower oil can be bought in capsule form.

Growing borage: problem solving

Borage is generally trouble free and easy to grow. The young growth of borage sometimes becomes infected with blackfly, which makes it a useful companion plant to broad beans, as it can lure blackfly away from your beans.

Older borage plants can become top heavy and flop over. Ideally, support plants with short canes and string before they topple.

Borage varieties to grow

Borago officinalis – the most common and widely available borage, with star-shaped blue flowers

Borago officinalis ‘Alba’ – this rarely grown variety has white flowers

Borago pygmaea – Pygmy borage is a low-growing, perennial variety, bearing attractive, small blue flowers from June to October