Planting Rosemary
Rosemary is a warm season herb in the Lamiaceae family. Getting the timing right is the difference between a strong stand and a disappointing one, so the windows below are given relative to your own last spring frost and first fall frost rather than a generic calendar date. Look up your local frost dates and count back or forward from there.
Rosemary is started indoors 8–10 weeks before your last spring frost date, giving seedlings a head start before they move outside.
Transplant young plants outdoors 1–2 weeks after your last frost, once the danger of frost has passed.
Rosemary can be grown by starting indoors and transplanting. Starting indoors gives the longest, most controlled season, while direct sowing is simplest where the season is long enough.
Spacing and Planting Depth
Give Rosemary room to mature. The figures below come from verified extension and seed-supplier data for typical varieties.
| Spacing in row | 18 inches |
|---|---|
| Row spacing | 24 inches |
| Plants per sq ft | 0.33 |
| Planting depth | 0.25 inches |
| Sun requirement | Full sun |
Days to Maturity
Rosemary reaches maturity in 80–100 days from transplant.
Rosemary is ready to harvest after about 90 days. Harvest before the first fall frost, which will end the plant's productive season.
Conditions and Care
As a warm-season herb, Rosemary needs warm soil and settled weather to thrive, and is set back or killed by frost. It is half-hardy — it withstands light frost but should be protected from a hard freeze.
Rosemary needs full sun — give it at least six hours of direct light a day for the best growth and flavor. Sow seed about 0.25 inches deep — small seed is sown shallow and barely covered, then keep the soil evenly moist until seedlings establish.
Rosemary belongs to the Lamiaceae family; rotating where you grow members of this family each year helps limit the build-up of soil-borne pests and disease. Rosemary is generally grown as a single planting each season rather than succession sown.
Companion Plants
Pairing Rosemary with the right neighbors can improve growth and deter pests; a few combinations are best avoided.
Grows well with: Cabbage, Carrots, Green Beans (Bush)
Growing Notes
Perennial in warm zones; slow from seed.