How to grow borage
Family Boraginaceae. Hardy to USDA hardiness zone 3a+ (U.S. Department of Agriculture). Full sun to part shade. Ready in 55-75 days.
Sun
Full sun to part shade
Spacing
12-18 in
Days to harvest
55-75 days
Hardiness
Zone 3a+
What growers actually recorded
Loading zone 7b results…
When to plant borage
- Direct sow: ~1 weeks after last frost.
Companion plants for borage
Plant with: Tomato, Squash, Strawberry.
Common pests & problems
Rarely bothered.
Grower's tip
Self-sows readily; let one plant go to seed each year and it will keep reappearing on its own.
When to plant borage in your zone
Free month-by-month sowing and transplanting lists, built from frost dates for your USDA (United States Department of Agriculture) hardiness zone.
Soil & water for borage
Soil & pH
6.0-7.0: near neutral
Loose, well-drained loam with 3-5% organic matter.
Compost 2 in worked into the top 6 in of soil each spring.
Watering
1 in / week while establishing; drought-tolerant once mature
Base watering; established borage tolerates dry spells well due to its deep taproot.
Water during establishment; mature plants need little supplemental water outside of prolonged drought.
Knowing when to harvest
- Pick young, tender leaves before flowering for the mildest, least bristly texture; older leaves turn coarse and prickly.
- Harvest star-shaped blue flowers as they open, ideally the same day, for garnish use; they wilt and brown quickly once picked.
Storing & keeping
Borage does not store or dry well; leaves wilt within hours and flowers within a day of picking. Flowers can be frozen in ice cubes for a short-term decorative use. Neither part is typically preserved long-term.
What to expect
Per plant: Continuous small harvests of flowers through a long bloom period; self-sown volunteers often provide more plants than are ever deliberately planted
Troubleshooting borage
Borage has taken over a bed the year after planting
Likely cause: Borage self-sows extremely heavily and volunteer seedlings are common and vigorous
What to do: Deadhead spent flowers before seed sets if self-seeding is unwanted, or treat it as a self-sustaining patch and thin volunteers each spring.
Leaves and stems feel bristly or irritate skin
Likely cause: Normal borage trait: leaves and stems are covered in stiff hairs
What to do: Handle with gloves if sensitive; this doesn't indicate a problem with the plant.
Varieties worth growing
Common borage (Borago officinalis, seed-grown standard)
The species typically grown; valued mainly as a pollinator plant and for its edible blue flowers used as garnish.
Growing borage in containers
Grows in a large container but its deep taproot and sprawling habit (2-3 ft) suit open garden ground better; it also self-sows less predictably in a contained pot, which some growers prefer.
Nutrition
Borage leaves contain pyrrolizidine alkaloids, compounds associated with liver toxicity with regular consumption; the flowers contain much lower levels and are the part most commonly used as an occasional garnish. Borage leaf is not intended for routine or medicinal-dose consumption, and pregnant or nursing individuals should avoid it altogether.
Common questions
Is it safe to eat borage leaves regularly?
No. Borage leaves contain pyrrolizidine alkaloids linked to liver toxicity with regular use. Occasional culinary use of the flowers (which contain far less of the compound) as a garnish is the more common and lower-risk use; borage leaf should not be treated as a everyday salad green.
Why is borage everywhere in my garden this year?
Borage self-sows prolifically once flowers set seed. Many gardeners let a patch self-sustain year after year for the pollinators it attracts, but deadheading before seed drop limits the spread.
Where these numbers come from
- USDA Plant Hardiness Zone Map (2023 revision). Zone assignment and the 30-year normals behind every cold-hardiness figure.
- NOAA NCEI 1991-2020 Climate Normals. Frost dates, growing-season length, and the probability bands on both.
- Cornell, UMN, and UC Davis Cooperative Extension crop guides. Spacing, days to maturity, soil pH targets, and per-plant yield ranges.
- USDA FSIS / FDA Produce Safety guidance. Wash, cure, and cold-storage handling numbers.
Ranges are regional guidance, not a promise for your yard. Your own logged results always override the published range.