How to grow rosemary
Salvia rosmarinus · Lamiaceae · Herb
When to plant rosemary: the short answer
Start seeds indoors about 10 weeks before your last spring frost; plant out about 1 week after it. Wait until the soil is at least 60°F; rosemary sprout fastest near 70°F.
Zone 5: plant out Apr 30 – May 17. Zone 7: plant out Apr 5 – Apr 22. Zone 9: plant out Feb 20 – Mar 9. See every zone.
Rosemary is a warm-season herb in the Lamiaceae family, usually started indoors and set out as transplants. It wants full sun (six or more hours of direct light) and little supplemental water once established. From sowing to first pick is about 90–120 days. It shrugs off a light frost but a hard freeze will damage it.
Grower’s note: Best bought as a plant - seed germinates slowly and unevenly. A woody perennial only where winters stay above about 0 F (roughly Zone 7); colder than that, grow it in a pot and bring it indoors. Full sun, dry feet, no rich soil.
Sowing
Sow barely covered — the seed needs light to germinate, into soil between 60–80°F — germination is quickest near 70°F. It is slow and often erratic to germinate (14–28 days). For an early crop, start seed indoors about 10 weeks before your last spring frost and grow it under bright light.
Spacing & layout
Give each plant about 24″ along the row with roughly 30″ between rows. On a square-foot grid that is one plant per 4 square feet. 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
Rosemary needs roughly 90–120 frost-free days to crop. Where the season is shorter than that, start it indoors and choose the earliest-maturing varieties, or grow it in a container you can move under cover on cold nights. In long, hot-summer regions it can often be planted twice — once in spring and again in mid-to-late summer for a fall harvest.
Quick facts
Growth stages: how long rosemary takes to grow
From seed to first harvest takes roughly 24-28 weeks: about 11 weeks as a seedling indoors, then 90-120 days in the garden.
When to plant rosemary
When to plant rosemary 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 |
|---|---|---|---|
| Zone 3 | May 15 / Sep 15 | Feb 27 – Mar 13 | May 15 – Jun 1 |
| Zone 4 | May 10 / Sep 25 | Feb 22 – Mar 8 | May 10 – May 27 |
| Zone 5 | Apr 30 / Oct 5 | Feb 12 – Feb 26 | Apr 30 – May 17 |
| Zone 6 | Apr 15 / Oct 15 | Jan 28 – Feb 11 | Apr 15 – May 2 |
| Zone 7 | Apr 5 / Oct 25 | Jan 18 – Feb 1 | Apr 5 – Apr 22 |
| Zone 8 | Mar 20 / Nov 5 | Jan 2 – Jan 16 | Mar 20 – Apr 6 |
| Zone 9 | Feb 20 / Nov 30 | Dec 5 – Dec 19 | Feb 20 – Mar 9 |
| Zone 10 | Jan 30 / Dec 15 | Nov 14 – Nov 28 | Jan 30 – Feb 16 |
Compare with the other herbs: when to plant herbs, by zone.
Companions
Cabbage, Bush Bean, Carrot, Sage
No strong antagonists recorded.
Common problems
Pests: aphids, spittlebug, spider mite.
Diseases & disorders: root rot, powdery mildew.
Same family (Lamiaceae)
Rotate these so they don’t follow each other in the same bed year to year.
Questions gardeners ask
When should I plant rosemary?
Start seeds indoors about 10 weeks before your last spring frost; plant out about 1 week after it. Wait until the soil is at least 60°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 rosemary take to grow?
About 90-120 days from transplanting to the first harvest, or roughly 24-28 weeks from sowing the seed indoors. Seeds germinate in 14-28 days.
How much sun does rosemary need?
It needs at least six to eight hours of direct sun a day.
What soil pH does rosemary 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 rosemary?
Space plants about 24 inches apart in rows 30 inches apart, or one plant per 4 square feet in a square-foot bed. Sow seeds about ⅛ inch deep.
Can I grow rosemary 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.