Borage is an annual in the Boraginaceae family. It is a prolific seeder so can become a nuisance if it is allowed to mature. The species name shows that it has medicinal uses. Borage or Starflower oil, pressed from the seeds is high in gamma-linoleic acid (GLA) which can help to reduce blood cholesterol levels and blood pressure. The leaves can be used to induce sweating, as a diuretic, to sooth a sore throat and applied externally to sooth irritated skin - it also contains harmful alkaloids so should only be taken medicinally if prescribed by a herbalist.
There are also culinary uses for Borage due to the cucumber flavour of the leaves. Young leaves and flowers make a garnish for salads. Chopped leaves can be added to soups or cooked with cabbage (one third Borage). Perhaps the best known use is the addition to drinks - the flowers and finely chopped leaves can be included with Pimms or fruit punches.
Borage is an important nectar source for Honeybees.

The dark green, ovate leaves have wavy edges arranged alternately on the stems. A mature plant has many stems which are hollow and can be up to 70 cm in height. The lower leaves and stems are covered with stiff hairs.
The flowers are star-shaped and can have a number of shades of blues and pinks with black anthers in their centres.

Hoe or hand pull seedlings, more mature plants have large taptoots. The hairs can be very irritant, so it may be advisable to wear gloves when handling them. Also a mask may be needed to avoid inhaling them, especially if the foliage has dried.
Weedkillers to use:-
A residual herbicide to supress germination.
Paraquat, Diquat, contact action killing top growth, apply before flowering.
Glyphosate kills the whole plant, but it may be capable of shedding viable seed.