🌱 Borage

Sowing window (UK)	April to June
Minimum soil temperature	5°C at seed depth
Sowing depth	2 cm
Spacing	50 cm apart
Days to germination	7 days
Days to harvest	56 days
Sowing method	Direct sow outdoors
Frost hardy	Yes
Sun	full-sun
Watering	low
Plant family	Boraginaceae

When should I sow Borage in the UK?

In the UK, sow Borage from April to June. It is normally sown direct outdoors. Wait until the soil has reached 5°C at seed depth rather than going by the calendar - borage will sit and rot in cold ground.

What soil temperature does Borage need to germinate?

Borage needs a minimum soil temperature of 5°C at seed depth to germinate reliably. Below that, germination is slow and patchy, and seed is more likely to rot than sprout. Measure at around 5cm down, in the morning, rather than trusting air temperature.

How deep and how far apart should I sow Borage?

For Borage, sow it 2cm deep and space plants 50cm apart.

How long does Borage take to grow?

Borage takes roughly 56 days from sowing to harvest. Seed usually germinates in about 7 days.

Is Borage frost hardy?

Yes. Borage is frost hardy and will stand through UK frosts, so it can be left out over winter in most of the country.

Sowing data cross-checked against RHS growing guides and UK seed-merchant catalogues. Soil temperatures are the minimum for reliable germination, measured at seed depth.