Quick answer: Rosemary (Salvia rosmarinus) can grown in San Francisco, CA (USDA zone 10b, Pacific Coast). Plant indoors 10 weeks before the last frost on Feb 15. Use a 3-gallon, 10" deep container with sandy; loamy; well-drained; alkaline tolerant, pH 6–7. Water every 1-2 days at peak summer — San Francisco's cool Mediterranean climate is reasonably forgiving. Expect harvest in 80–100 days.
Why grow Rosemary in San Francisco?
San Francisco sits in USDA zone 10b (heat zone 5) with a Csb (cool Mediterranean) climate (Köppen-Geiger / VU Wien) — Pacific Coast. Summer highs reach 70°F (NOAA NCEI) and winter lows fall to 46°F, at 650ft elevation (USGS). Rosemary prefers USDA zones 7–10, killed below 15°F. Rosemary fits the local zone window with normal container care. Surrounding metros — Broadmoor, Daly City, and Brisbane — share the same climate, so this guide largely applies to them too.
The 295-day growing season (Feb 15 to Dec 10) gives you plenty of runway for rosemary, which take 80–100 days to mature. San Francisco averages 2600 hours of sunshine annually with 100 chill hours per winter — rosemary only need 6–8 hours daily, so light is never the problem. The game in San Francisco is matching variety to your local microclimate.
Metro-wide climate notes: Broadmoor and Daly City sit in the same zone 10b cool Mediterranean basin as San Francisco, while Brisbane at slightly higher elevation runs 2-3°F cooler in winter. South San Francisco in the lower valley shares San Francisco's frost dates almost exactly. The rosemary growing strategies in this guide apply across the entire metro.
Also known as: Anthos; Old Man; Sea Dew; Rosmarinus officinalis · Family: Lamiaceae · Perennial edible.
When to plant in San Francisco
San Francisco's climate gives you a clear rosemary window from spring through fall. Here are the dates that actually matter.
The San Francisco Rosemary calendar
- Start seeds indoors: 10 weeks before Feb 15
- Transplant outdoors (spring): After Feb 15 when soil temp ≥ 60°F
- First harvest: Mid-summer on early-maturing cultivars
- Peak production: Mid- to late summer
- Final harvest: Before Dec 10
Container setup for San Francisco
Rosemary needs a 3-gallon minimum, 10" deep container. Mature plants reach 48" tall × 36" wide.
Material warning for San Francisco: with 75% average humidity, drainage is the priority — non-breathable containers stay wet too long. Use:
- Fabric pots — air-prune roots, breathable
- Quality plastic with drainage — durable and affordable
- Glazed ceramic — attractive and stable
Soil: Sandy; loamy; well-drained; alkaline tolerant, pH 6–7. Local soil: San Francisco's native soil is loam (matters for in-ground; containers use potting mix regardless).
Best rosemary varieties for San Francisco
San Francisco growers do well with these popular varieties (from breeders' lists). Pick by flavor and growth habit:
- Tuscan Blue
- Arp
- Prostrate (Huntington Carpet)
- Salem
- Spice Islands
Care routine for San Francisco
Water
Container-grown rosemary in San Francisco needs water every 1–2 days at peak summer. Rosemarys are a Low water-category plant with a baseline of every 5 days in containers. With only 23.6" of annual rainfall and 75% average humidity, weather provides almost no help. San Francisco has high water restrictions — drip irrigation and morning watering (before 8am) are both efficiency-smart and rule-compliant.
Metro-wide note: San Francisco and surrounding Broadmoor, Daly City, Brisbane all share regional water management, so the high restriction schedule below applies regionally.
Fertilizer
Rosemarys are a light feeder. Use a 05-10-05 (matched to flowering-and-fruiting stage) fertilizer once flowers appear. In containers, nutrients leach with every watering — feed weekly at half strength rather than monthly at full.
Sun
Rosemarys need 6–8 hours of Full Sun. In San Francisco, morning sun with light afternoon protection during heat waves keeps plants productive without scorching.
Pests & diseases in San Francisco
Priority pests (San Francisco + Rosemary intersection)
Both rosemary and gardens in San Francisco are commonly affected by aphids; spider mites; whiteflies. These deserve weekly inspection — weekly inspection catches problems early.
Also watch for (rosemary-specific, less common locally): scale; spittlebugs.
Common rosemary diseases: powdery mildew; root rot; botrytis. San Francisco's temperate climate carries moderate disease pressure; airflow and dawn watering keep most issues in check.
Companion plants & what to avoid
Good companions: beans; cabbage; carrots; sage; thyme.
Avoid planting with: basil; cucumbers; pumpkins; squash.
Pollination: Rosemarys are self-pollinating — a single plant will set fruit on its own.
Wildlife & pet safety
Deer pressure in San Francisco: low (urban metro). Rosemarys are deer-resistant — still good practice to plant within sight of the house in higher-pressure suburbs.
Pet safety: Toxic to cats: No · Toxic to dogs: No. Non-toxic per ASPCA; safe for humans and pets in culinary amounts; large medicinal doses may be problematic
Harvest expectations
Expect 1 in San Francisco containers.
Local harvest months: summer through first frost. Standard harvest months elsewhere: Jan; Feb; Mar; Apr; May; Jun; Jul; Aug; Sep; Oct; Nov; Dec. Once a plant starts fruiting, expect a 365-day harvest window per planting.
What you harvest: leaves; flowers. Culinary uses: roasted meats; potatoes; breads; focaccia; herb oils; teas; cocktails; marinades; vinegars.
Grower's tips for Rosemary
Use terracotta pots for best drainage; water only when soil dries 2 inches down; bring indoors before frost in zones below 7; place in cool bright location indoors over winter; do not overwater (most common cause of death); Arp variety is most cold-hardy
Common San Francisco rosemary mistakes
- Overwatering causing root rot.
- poor drainage.
- pruning into old wood.
- insufficient sunlight indoors over winter.
- sudden temperature changes.
- Treating San Francisco's shoulder seasons like midsummer — variable spring and fall weather punishes calendar planting.
San Francisco rosemary FAQ
Does this San Francisco guide apply to Broadmoor, Daly City, Brisbane?
Yes — Broadmoor, Daly City, Brisbane, South San Francisco all share San Francisco's USDA zone 10b, Csb climate, and 295-day growing season. The varieties, planting calendar, and care advice in this guide apply across the entire metro. Subtle elevation differences shift frost dates by only a few days.
Can I grow rosemary year-round in San Francisco?
San Francisco's 295-day growing season covers spring through fall. Year-round only with indoor or protected cultivation in winter.
What's the best month to plant rosemary in San Francisco?
Transplant after the last frost on Feb 15 when soil temp at 4" reads ≥ 60°F. Start seeds indoors 10 weeks earlier.
Do I need a greenhouse for rosemary in San Francisco?
Not required, but a season-extension structure helps in shoulder months. Most San Francisco growers do fine with open-air containers.
How much sun do rosemary need in San Francisco?
Rosemarys need 6–8 hours of direct sun. San Francisco delivers 2600 annual sunshine hours — plenty for full production with a south or west exposure.
What USDA zone is San Francisco?
San Francisco is in USDA hardiness zone 10b with AHS heat zone 5. Last frost typically Feb 15, first frost Dec 10, giving a 295-day growing season.
Where can I buy rosemary seedlings near San Francisco?
Check San Francisco's 28 farmers markets and local nurseries. Your state extension (https://ucanr.edu) lists certified suppliers and runs seasonal plant sales. 25 community gardens across the metro also share seedlings.
Are rosemary safe for my pets in San Francisco?
Toxic to cats: No; toxic to dogs: No. Non-toxic per ASPCA; safe for humans and pets in culinary amounts; large medicinal doses may be problematic Keep curious pets out of the container or use a cage.
How much water do rosemary use in San Francisco?
A 3-gallon container needs roughly 0.5–1 gallon per day in summer (sometimes 2 gallons during heat waves). San Francisco's high water restrictions limit watering times, not amounts — drip irrigation and morning watering before 8am stays efficient and compliant. Rainfall averages 23.6" annually.
San Francisco gardening resources
- State extension: California Cooperative Extension
- Region: Pacific Coast · San Francisco County, California · population 881,549
- Community gardens: approximately 25 across the San Francisco metro
- Farmers markets: 28 registered with USDA AMS
- Elevation: 650ft above sea level
- Nearby cities: Broadmoor gardening guide · Daly City gardening guide · Brisbane gardening guide · South San Francisco gardening guide
Data sources
Climate, geographic, and toxicity data on this page come from public datasets. Cultivar profiles and growing recommendations draw on land-grant university extension research.
- USDA 2023 Plant Hardiness Zone Map (USDA Agricultural Research Service) — https://planthardiness.ars.usda.gov/ — Data via PRISM Climate Group, Oregon State University
- NOAA Climate Normals 1991-2020 (NOAA National Centers for Environmental Information) — https://www.ncei.noaa.gov/products/land-based-station/us-climate-normals
- Köppen-Geiger Climate Classification (US Counties) (Vienna University (TU Wien)) — https://koeppen-geiger.vu-wien.ac.at/usa.htm
- USGS Elevation Point Query Service (U.S. Geological Survey) — https://epqs.nationalmap.gov/
- USDA AMS National Farmers Market Directory (USDA Agricultural Marketing Service) — https://www.ams.usda.gov/local-food-directories/farmersmarkets
- ASPCA Toxic and Non-Toxic Plant List (American Society for the Prevention of Cruelty to Animals) — https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants
- California Cooperative Extension (California) — https://ucanr.edu