When to plant rosemary by city
Plant rosemary out 1–3 weeks after your last frost. Here is what that means for 2027 in cities across the US, using each city’s average frost dates (NOAA 1991–2020). Pick the city with the climate most like yours, or enter your ZIP code above.
| City | Last frost | Plant out |
|---|---|---|
| Seattle, WA (9a) | Mar 13 | Mar 20 – Apr 3 |
| Portland, OR (8b) | Feb 25 | Mar 4–18 |
| Sacramento, CA (9b) | Jan 12 | Jan 19 – Feb 2 |
| Phoenix, AZ (10a) | Jan 5 | Jan 12–26 |
| Salt Lake City, UT (7b) | Mar 31 | Apr 7–21 |
| Denver, CO (6a) | Apr 30 | May 7–21 |
| Dallas, TX (8b) | Mar 2 | Mar 9–23 |
| Minneapolis, MN (5a) | Apr 23 | Apr 30 – May 14 |
| Kansas City, MO (6b) | Apr 4 | Apr 11–25 |
| Chicago, IL (6b) | Apr 10 | Apr 17 – May 1 |
| Columbus, OH (6b) | Apr 20 | Apr 27 – May 11 |
| Nashville, TN (7b) | Apr 1 | Apr 8–22 |
| Atlanta, GA (8a) | Mar 24 | Mar 31 – Apr 14 |
| Raleigh, NC (8a) | Mar 28 | Apr 4–18 |
| Philadelphia, PA (7b) | Mar 30 | Apr 6–20 |
| Boston, MA (7a) | Apr 4 | Apr 11–25 |
In frost-free parts of Florida, southern California and the Gulf Coast, timing is about heat instead: grow rosemary from fall through winter.
Rosemary spacing
In a square-foot bed, plant 1 per square foot. In traditional rows, space plants about 24 inches apart with 36 inches between rows.
Perennial in zone 7 and warmer; elsewhere grow it in a pot and bring it in.
How to grow rosemary
Rosemary is a woody evergreen shrub that is perennial in zone 7 and warmer, where it can grow several feet tall. In colder areas it is best grown in a pot that spends summer outdoors and winter in a bright, cool spot indoors. It wants sun, heat and very sharp drainage.
Sun and soil
Full sun and light, sandy or rocky, well-drained soil that is slightly acidic to neutral. Rosemary tolerates drought and poor soil but not wet roots or heavy clay.
Planting
- Buy plants or root cuttings; seed is slow and germinates poorly.
- Plant out 1–3 weeks after the last frost, when soil is about 60°F.
- In the ground, space plants 24 inches apart in rows 36 inches apart.
- In zone 6 and colder, plant in a terra cotta pot with drainage holes so you can bring it indoors before hard frost.
Care
- Let the soil dry between waterings. Overwatering is the most common way rosemary dies, indoors and out.
- Feed little if at all.
- Trim lightly after flowering to keep plants dense.
- Where it is borderline hardy, choose a cold-tolerant variety and plant it in a sheltered spot with good drainage.
Harvest
Snip sprigs as needed year-round, taking no more than about a third of the plant at once. Leaves dry well when stems are hung in a dry, airy place.
Common problems
- Root rot: Plants brown and die from the base up in soggy soil. Improve drainage, use a gritty mix in pots, and water sparingly.
- Powdery mildew: Common indoors in winter. Give plants bright light and good air circulation.
- Spider mites, aphids and mealybugs: Mostly a problem on indoor plants. Rinse foliage and use insecticidal soap if needed.
- Winter kill: Plants die in cold, wet winters at the edge of their range. Grow hardy varieties or overwinter in pots indoors.
Varieties to try
- 'Arp' — one of the most cold-hardy rosemaries
- 'Hill Hardy' (also sold as 'Madeline Hill') — another cold-tolerant choice
- 'Tuscan Blue' — upright and fast-growing, deep blue flowers
- 'Prostratus' — trailing habit, less cold hardy
Crop rotation
Rosemary belong to the mint family (Lamiaceae). Mostly herbs and perennials; rotation matters little. Relatives that count as the same family for rotation: basil, mint, oregano, thyme, sage.
Frequently asked questions
When should I plant rosemary?
How far apart should I plant rosemary?
How long do rosemary take to grow?
Can rosemary handle frost?
Sources
- Frost dates: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020.
- Hardiness zones: 2023 USDA Plant Hardiness Zone Map, USDA-ARS and PRISM Climate Group, Oregon State University.
- Planting windows and spacing: Vegetable Planting Guide (GardenNotes #720), Colorado State University Extension, and other land-grant extension guides.
- Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023
- Salvia rosmarinus (rosemary) — NC State Extension Plant Toolbox
- Herbs — Clemson Cooperative Extension (HGIC)