Crops Borage (Borago officinalis)

Borage, plants in flower

Borage is a stout, fleshy annual, often growing to 1 m in height, many of the vegetative parts being covered with whitish prickly hairs. The stems are round and hollow, often much-branched.

Borage, seedlings

Leaves are dark grey-green, oval-pointed in shape, wrinkled and with prominent veins underneath. The flowers are produced in loose clusters at the ends of the stems; flowers are star-shaped, with 5 petals, usually a vivid blue colour though sometimes pink or white, with a dark centre.

Ripening seeds

The petals soon fall, leaving 3 or 4 nutlets, which ripen rapidly to deep brown or black and are then shed, usually before some higher flowers in the same group are open.

Seeds

Since the flowering season is long, each branch is likely to have buds, open flowers, ripening seeds and empty sepals at the same time. The crop prefers a light soil and an open sunny situation. For seed production borage is best sown during late March or April, drilled at about 2 cm depth into a relatively rough seedbed. Ideal population is probably 25-30 plants per square metre, which should be achieved from a sowing rate of 15-20 kg per ha. Row width may be either wide or narrow, the latter making for better harvesting, wide rows permitting mechanical weeding; there are few possible herbicides, but established borage should smother most weeds. Up to 75 kg per ha of nitrogen fertiliser may be applied to the seedbed or the emerging crop. Flowering usually commences about mid-June and may continue through September: seed shedding may commence in late July, which is when the crop should be cut and swathed. Combining follows when sufficient moisture has been lost from the leaves (generally after about 5 days). Yields are variable, a high proportion of the potential crop usually being lost, but 0.4-0.5 t per ha should be generally attainable.