How to grow borage
Borago officinalis · Boraginaceae · Herb
When to plant borage: the short answer
Sow outdoors about 2 weeks before the last frost; for a fall crop, sow about 8 weeks before your first fall frost. Seeds germinate in soil from 55 to 80°F, fastest near 68°F.
Cold winters (zone 5): sow Apr 11 – Apr 30, or sow Jul 31 – Aug 17 for a fall crop. Mild winters (zone 9): sow Sep 25 – Oct 12 for fall and winter harvests; the spring window (Feb 1 – Feb 20) closes before the summer heat. Skip the hottest months for borage. See every zone.
Borage is a cool-season herb in the Boraginaceae family, almost always sown straight into the ground where it will grow. It wants full sun, though it tolerates a little afternoon shade in hot regions and steady, even moisture. From sowing to first pick is about 55–75 days. It shrugs off a light frost but a hard freeze will damage it.
Grower’s note: Grown mainly for its brilliant blue star flowers, which draw in bees and are edible with a cucumber taste. A big, bristly, fast annual that reseeds everywhere once established - a traditional companion near tomatoes and squash.
Sowing
Sow about 0.5″ deep, into soil between 55–80°F — germination is quickest near 68°F. It comes up fast (5–15 days). It does not transplant well, so sow it in its final position rather than starting it in pots.
Spacing & layout
Give each plant about 12″ along the row with roughly 18″ between rows. On a square-foot grid that is 1 per square foot. Allow at least 12″ of loose, workable soil for the roots. It grows well in containers at least 12″ deep.
Fitting it to your season
As a cool-season crop, borage does its best growing in the mild weather of spring and fall and tends to bolt or turn bitter in summer heat. A second sowing in late summer, timed to mature as the weather cools, is usually the better crop of the year — though a hard freeze will end it.
Quick facts
Growth stages: how long borage takes to grow
From sowing to first harvest takes roughly 55-75 days (8-11 weeks), with seedlings appearing after 5-15 days in soil around 68°F.
When to plant borage
When to plant borage by USDA zone
Dates worked out from each zone’s typical frost dates for 2026. Find your zone on the zone map, or pick your state below for dates from its own frost dates. Zones 11 and above are frost-free, so timing there depends on heat and rain instead.
| Zone | Last / first frost | Start indoors | Sow or plant out | Fall or second sowing |
|---|---|---|---|---|
| Zone 3 | May 15 / Sep 15 | - | Apr 26 – May 15 | Jul 11 – Jul 28 |
| Zone 4 | May 10 / Sep 25 | - | Apr 21 – May 10 | Jul 21 – Aug 7 |
| Zone 5 | Apr 30 / Oct 5 | - | Apr 11 – Apr 30 | Jul 31 – Aug 17 |
| Zone 6 | Apr 15 / Oct 15 | - | Mar 27 – Apr 15 | Aug 10 – Aug 27 |
| Zone 7 | Apr 5 / Oct 25 | - | Mar 17 – Apr 5 | Aug 20 – Sep 6 |
| Zone 8 | Mar 20 / Nov 5 | - | Mar 1 – Mar 20 | Aug 31 – Sep 17 |
| Zone 9 | Feb 20 / Nov 30 | - | Feb 1 – Feb 20 | Sep 25 – Oct 12 |
| Zone 10 | Jan 30 / Dec 15 | - | Jan 11 – Jan 30 | Oct 10 – Oct 27 |
Compare with the other herbs: when to plant herbs, by zone.
Companions
Tomato, Zucchini / Summer Squash, Swiss Chard
No strong antagonists recorded.
Common problems
Pests: aphids.
Diseases & disorders: powdery mildew.
Questions gardeners ask
When should I plant borage?
Sow outdoors about 2 weeks before the last frost; for a fall crop, sow about 8 weeks before your first fall frost. Seeds germinate in soil from 55 to 80°F. The table on this page gives dates for each USDA zone, and the planting calendar gives dates for your own state or ZIP code.
How long does borage take to grow?
About 55-75 days from sowing to the first harvest. Seeds germinate in 5-15 days, fastest in soil around 68°F.
How much sun does borage need?
It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough.
What soil pH does borage need?
A soil pH between 6.0 and 7.5. Test before adding lime or sulfur - see the soil pH and testing guide.
How far apart should I plant borage?
Space plants about 12 inches apart in rows 18 inches apart, or 1 per square foot in a square-foot bed. Sow seeds about ½ inch deep.
Can I grow borage in a container?
Yes. Use a container at least 12 inches deep with drainage holes and a good potting mix, and water more often than you would in the ground.
Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.