Crop guide · The borage family

How to grow borage

A fast-growing annual herb bearing vivid blue star-shaped flowers and cucumber-scented leaves, valued by pollinators and kitchen gardeners alike.

Borago officinalis · also called starflower, bee bread

Full sun Beginner Half-hardy
Sun
Full sun
Light afternoon shade once temperatures stay above 90 °F (32 °C) helps extend flowering and slows bolting (the shift from leaf growth to flowering).
Frost
Half-hardy
Tolerates a light frost once established
Spacing
12 in
30 cm between plants
Sow depth
0.375 in
10 mm
To harvest
50–70 days
counted from sowing
Soil pH
6.0–7.0
slightly acidic to neutral
Timing

When to plant borage

Windows are counted from the average date of your last spring frost.

Fall planting:8–10 weeks before first fall frost for a late-season flush.
Too late?Skip a spring sowing once daytime temperatures regularly exceed 85 °F (29 °C) and nights stay warm — sow again in late summer for a fall crop.
Background

Why grow borage

Borage flowers and young leaves add a mild cucumber flavor to salads, drinks, and garnishes. Its prolific blooms attract bees and other beneficial insects across a long season, making it a practical companion in any kitchen garden.

A little history. Native to the Mediterranean region, borage is a coarse-stemmed annual covered in stiff white hairs. Its nodding blue flowers are among the few truly blue edible blooms in cultivation, and the plant self-seeds reliably once established.

The season, step by step

From planting to harvest

Sow outside

2–4 weeks before last frost

Sow seeds 0.375 inch (10 mm) deep, and aim for 12 inches (30 cm) between plants once thinned. Sow seeds 1/4–1/2 inch deep and keep the seedbed evenly moist until sprouts show; borage dislikes transplanting, so sow in place. Seedlings emerge in 5–14 days.

Best soil temp 65–75 °F (18–24 °C) Minimum 50 °F (10 °C) Emerges in 5–14 days

Water and feed

All season

Water deeply once or twice a week; reduce frequency once plants are established and growing vigorously. Water when the top inch of soil feels dry to the touch. Aim for about 1 inch per week including rain.

A single side-dress (scatter fertilizer along the row and water in) at planting is usually sufficient for the season. What to use: low-nitrogen balanced compost or a 5–5-5 organic granular; excess nitrogen promotes leaves at the expense of flowers.

Prune and maintain

As it grows

Pinch out the growing tip when plants reach 12 inches to encourage branching and more flower stems. Deadhead (remove spent blooms) regularly to extend the flowering period and reduce unwanted self-seeding.

Harvest and store

50–70 days from sowing

It's ready when harvest individual flowers as soon as they are fully open and vivid blue. Pick young leaves — no larger than 2–3 inches — before the surface hairs become coarse and bristly. Pinch individual flowers at the base of the corolla (the ring of petals) with thumb and forefinger. Snip young leaves with scissors close to the stem. Harvest in the morning after dew has dried for best flavor.

Use flowers immediately — they wilt within hours of picking. Young leaves keep 1–2 days wrapped in a damp paper towel in the refrigerator. Freeze flowers in ice cubes for longer storage.

Companions

Good neighbours, bad neighbours

Plant it with

Tomato

Borage blooms almost nonstop and pulls bumblebees into the bed. Tomato flowers set fruit on their own, but the vibration of a visiting bumblebee shakes pollen loose and can improve fruit set on stubborn early trusses.

Zucchini

Zucchini carries separate male and female flowers and depends on insects to move pollen between them. Borage flowering nearby reliably draws bees into the patch, which reduces the shriveled, unfilled young fruit that follows poor pollination.

Strawberry

Each strawberry needs many separate pollen deliveries to swell evenly. Bee traffic drawn by borage often reduces the lopsided, hard-shouldered berries that come from incomplete pollination. Keep borage to the bed edge so it does not shade the crowns.

Cucumber

Standard garden cucumbers need bees to carry pollen from male to female flowers. Borage in bloom draws steady bee visits, which shows up as straighter, fully filled fruit rather than pinched or curled ones.

Cabbage

Borage flowers feed hoverflies, lacewings, and tiny parasitic wasps, and these hunters often reduce aphid and caterpillar numbers on nearby cabbage. Borage also hosts cabbage loopers itself, so check its leaves when you scout the cabbage.

Keep it away from

Fennel

Fennel roots release compounds that stunt most garden vegetables and herbs, borage included. Grow fennel in its own corner or a separate pot, where its flowers still feed hoverflies and tiny parasitic wasps without checking the growth of neighbours.

See borage in the full companion chart →

Crop rotation

After this crop

Family rest

Easy-going — Borage can grow almost anywhere in the rotation without a strict rest.

Good next crops

The pea and bean family, the cabbage family or the tomato family thrive in this ground next season.

An easy-going light feeder that takes little from the bed and leaves loose, well-worked soil behind, plus plenty of self-sown seedlings to pull. Wait one year before borage returns to the same ground. Peas or beans, cabbage-family greens, or tomatoes and peppers all follow well.

Trouble to watch for

Pests and diseases

Pests

Aphids

Sign
Clusters of small soft-bodied insects on new growth and flower buds; sticky residue on leaves below.
Fix
Knock off with a firm jet of water; repeat daily for several days. Introduce or encourage ladybirds and lacewings.

Cabbage loopers

Sign
Irregular holes in leaves; pale green caterpillars looping across the foliage.
Fix
Hand-pick caterpillars in the evening; apply a targeted biological spray containing Bacillus thuringiensis (a naturally occurring soil bacterium) if numbers are high.

Leafhoppers

Sign
Pale stippling or bleached patches on leaves; small wedge-shaped insects that jump when disturbed.
Fix
Remove heavily infested leaves; use row cover early in the season to exclude adults.

Diseases

Powdery mildew

Sign
White powdery coating on older leaves, typically appearing in mid to late summer as air circulation drops.
Prevent
Space plants at least 12 inches apart for airflow; avoid overhead watering in the evening. Remove affected leaves promptly.

Downy mildew

Sign
Yellow patches on the upper leaf surface with a grey-purple fuzzy growth on the underside in cool, humid conditions.
Prevent
Improve air circulation; water at the base of plants in the morning so foliage dries quickly. Avoid crowding.

Root rot

Sign
Wilting despite moist soil; stems soft and discolored at the base; roots brown and mushy.
Prevent
Ensure sharp drainage; never let pots or beds sit waterlogged. Raised beds or amended sandy loam reduce risk significantly.
Good to know:Borage contains low levels of pyrrolizidine alkaloids — compounds that can stress the liver in very large quantities. Culinary use of flowers and young leaves in normal amounts is considered safe, but avoid consuming large quantities daily over extended periods.
FAQ

Common questions about borage

When should I plant borage?
Spring: 2–4 weeks before last frost, once soil can be worked. Fall: 8–10 weeks before first fall frost for a late-season flush.
How long until borage is ready to harvest?
50–70 days, counted from sowing. It's ready when harvest individual flowers as soon as they are fully open and vivid blue. Pick young leaves — no larger than 2–3 inches — before the surface hairs become coarse and bristly.
Can I grow borage in a container?
Beds preferred — taproot resents confinement; containers work only in deep pots with excellent drainage. In containers: 3-gallon pot, at least 12 inches deep.
How often should I water borage?
Water deeply once or twice a week; reduce frequency once plants are established and growing vigorously. Water when the top inch of soil feels dry to the touch.
Is any part of borage unsafe to eat?
Borage contains low levels of pyrrolizidine alkaloids — compounds that can stress the liver in very large quantities. Culinary use of flowers and young leaves in normal amounts is considered safe, but avoid consuming large quantities daily over extended periods.
How should I store borage after harvest?
Use flowers immediately — they wilt within hours of picking. Young leaves keep 1–2 days wrapped in a damp paper towel in the refrigerator. Freeze flowers in ice cubes for longer storage.

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