When to plant Borage in Temperate Australia

Temperate zone — applies to Sydney, Melbourne, Adelaide, Perth, Newcastle and similar areas. Growing elsewhere? Cool · Subtropical · Tropical · Arid.

Sow borage direct from August to February, dropping seed 10 mm deep straight where it is to grow, as it resents transplanting. Germination takes 14–21 days, and this fast, hardy herb reaches flowering maturity in around 56–70 days. Space plants 30 cm apart with 30–45 cm between rows, giving the large, bristly plants plenty of room to sprawl. Borage self-seeds prolifically once established, so one spring sowing often becomes a permanent, self-renewing patch. Its edible blue star flowers draw bees and beneficial insects, making it a favourite companion near tomatoes, cucumbers and strawberries in temperate gardens around Sydney, Melbourne and Adelaide.

Sowing calendar — temperate zone

Green months are your sowing window: August to February.

Growing notes

Borage is about as easy as herbs come, and its real value lies in what it does for the rest of the garden. The nodding blue flowers are magnets for bees and hoverflies, so a clump near your tomatoes, cucumbers or strawberries improves pollination and fruit set, and gardeners have long paired it with these crops for exactly that reason. The young leaves and flowers are edible with a cucumber-like taste.

Because borage has a taproot, it dislikes being moved, so always sow it direct where it will grow rather than raising seedlings. Transplanted plants sulk and bolt early. Sow at a full 10 mm and keep the surface moist until the seedlings appear over 14–21 days.

The main failure mode is not disease but exuberance. Borage self-seeds so freely that it can become a nuisance, popping up across beds for years. If you want to keep it in check, cut the plants down before the flowers set seed, or simply pull the surplus seedlings as they appear. The large plants also flop and smother neighbours if crowded, so give the full 30 cm spacing. In hot, dry Adelaide summers the plants can wilt and brown off quickly, so water deeply and mulch, though they usually reseed and return regardless. Powdery mildew may appear on older leaves late in the season; just remove them.

Borage at a glance

Companion planting

Grows well with

Tomatoes: Deters tomato hornworm; attracts pollinators

Cucumber: Deters tomato hornworm; attracts pollinators for better fruit set

Strawberries: Traditionally thought to improve strawberry flavour; attracts pollinators

Common questions

does borage help tomatoes grow

Borage is a classic tomato companion. It draws bees and other pollinators that improve fruit set, and is traditionally thought to deter tomato hornworm. Planting a clump near tomatoes, cucumbers or strawberries benefits all three.

can you transplant borage seedlings

It is best not to. Borage has a taproot and resents disturbance, so sow it direct at 10 mm deep where it will grow. Transplanted plants tend to sulk and bolt early rather than settling in.

does borage come back every year

Borage is technically an annual, but it self-seeds so prolifically that a single sowing usually returns year after year as a self-renewing patch. If that is too much, cut plants before they set seed to keep it contained.

is borage a good companion plant

Yes, borage is one of the best companion herbs. Its bee-friendly flowers boost pollination for nearby tomatoes, cucumbers and strawberries, and it is traditionally credited with improving strawberry flavour and deterring hornworm.

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