Borage is often grown as a culinary plant in the herb garden. The flowers are rich in a sweet nectar and are very attractive to bees.
Although an annual, it usually maintains itself by self-sowing, sometimes in quite a prolific manner, as long as the soil is disturbed by hoeing etc. Plants often develop mildew when growing in dry conditions or towards the end of the growing season. Flowers are a deeper blue when grown in poorer soils.
The growing plant is a good companion for strawberries, tomatoes, courgettes and most other plants. It is said to deter Japanese beetle and tomato hornworms.
A very easily grown plant, succeeding in ordinary garden soil, preferring a dry soil and a sunny position. It grows particularly well in loose, stony soils with some chalk and sand. Plants are tolerant of poor dry soils, though much bigger specimens are produced when the plants are growing in better conditions.
Leaves - raw or cooked. They can be used as a pot-herb or be added to salads. They are also added whole as a flavouring to various drinks such as Pimms and wine-based drinks. The leaves are rich in potassium and calcium, they have a salty cucumber flavour. Very hairy, the whole leaves have an unpleasant feeling in the mouth and so they are best chopped up finely and added to other leaves when eaten in a salad. The leaves should always be used fresh, because they lose their flavour and colour if dried.
Flowers - raw. They are used as a decorative garnish on salads and summer fruit drinks. The flowers are very nice, both to look at and to taste with a sweet slightly cucumber-like flavour. A refreshing tea is made from the leaves and/or the flowers. The dried stems are used for flavouring beverages. The seed yields 30% oil, 20% of which is gamma-linolenic acid. Total yields are 0.35 - 0.65 tonnes per hectare. Unfortunately, the seed ripens intermittently over a period of time and falls from the plant when it is ripe, this makes harvesting the seeds in quantity very difficult.
An edible blue dye can be obtained from the flowers. It is used to colour vinegar.