Planting Guides

When to Plant Tomatoes in San Francisco: Complete Guide + Best Varieties for Zone 10a

San Francisco, California

USDA Zone 10a

Last Frost: Jan 15

Last updated: December 4, 2025

Learn when to plant tomatoes in San Francisco with specific dates for Zone 10a. Compare 6 varieties perfect for Bay Area microclimates and fog.

DDavid Kim

December 4, 2025

Tomato plants thriving in San Francisco rooftop garden with Bay Area skyline visible — — Image © PlantReference.org 2026

Quick Answer

Plant tomatoes in San Francisco March 1-April 15 for spring crop, August 1-September 15 for fall harvest. Choose fog-tolerant varieties.

TL;DR

San Francisco tomato planting: Start seeds January-February for spring crop, transplant March-April. Plant again August for fall harvest. Choose fog-tolerant varieties like 'Solanum lycopersicum 'Early Girl'' and 'Solanum lycopersicum 'Stupice'' for best results in Zone 10a's cool summers.

Frequently Asked Questions

When is the latest I can plant tomatoes in San Francisco?

For spring planting, April 15 is your cutoff date to ensure harvest before heavy fog season. For fall crops, plant by September 15 at the latest. Fall plantings actually perform better in many San Francisco microclimates because September-November often provides the warmest, driest weather of the year. Choose early varieties like 'Solanum lycopersicum 'Early Girl'' for late plantings to ensure harvest before December frost.

Do tomatoes grow year-round in San Francisco?

While San Francisco is Zone 10a with minimal frost, tomatoes don't truly grow year-round due to cool summer fog and reduced daylight in winter. The best approach is two distinct seasons: spring planting (March-April) for summer harvest, and fall planting (August-September) for autumn harvest. Some gardeners maintain plants through winter in protected microclimates, but production is minimal during the shortest days.

What tomato varieties handle San Francisco fog best?

Cool-tolerant varieties perform best in San Francisco's foggy conditions. 'Solanum lycopersicum 'Stupice'', 'Solanum lycopersicum 'Early Girl'', and 'Solanum lycopersicum 'Oregon Spring'' all set fruit in temperatures as low as 45°F (7°C). Avoid heat-lovers like 'Solanum lycopersicum 'Cherokee Purple'' unless you garden in the Mission District or other warm microclimates. Cherry tomatoes generally handle cool weather better than large beefsteak types.

How do San Francisco's microclimates affect tomato growing?

San Francisco's neighborhoods vary dramatically in growing conditions. Foggy areas (Richmond, Sunset) stay 10-15°F (5-8°C) cooler and need cold-tolerant varieties planted later in spring. Warm pockets (Mission, Potrero Hill) can grow heat-loving varieties and support longer seasons. Windy areas need extra staking and windbreaks. Choose your varieties and timing based on your specific neighborhood conditions rather than general San Francisco advice.

Should I grow tomatoes in containers or in the ground in San Francisco?

Containers offer significant advantages in San Francisco. You can move plants to follow sun, protect from unexpected cool spells, and avoid the city's heavy clay soil. Use 20-gallon minimum containers for indeterminate varieties. In-ground growing works well if you've amended the soil and chosen a protected, sunny location. Many successful San Francisco gardeners use raised beds as a compromise—better drainage than ground level, more root space than containers.

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Tagged with

#san francisco gardening #zone 10a tomatoes #bay area gardening #fog tolerant tomatoes #california tomato growing #urban gardening #container tomatoes #microclimate gardening #pacific coast gardening #cool climate tomatoes

Written By

David Kim

David is a software engineer who got into gardening after buying a fixer-upper in the Sunset District with a neglected backyard. San Francisco's microclimates fascinated him—he quickly learned that what grows three blocks away might not work in his fog belt yard. David now maintains a productive vegetable garden despite the marine layer, growing cool-season crops almost year-round and experimenting with season extension techniques. He volunteers at a local community garden and writes about urban food growing, microclimate gardening, and the particular challenges of Bay Area conditions. His approach is methodical—he keeps detailed notes and isn't afraid to share what didn't work.