Planting Guides

When to Plant Tomatoes in San Diego: Complete Guide + Best Varieties for Zone 10b

San Diego, California

USDA Zone 10b

Last Frost: Feb 1

Last updated: October 30, 2025

Plant tomatoes in San Diego year-round with peak seasons February-April and September-October for Zone 10b success.

EEmma Chen

October 30, 2025

Thriving tomato plants in San Diego garden with city skyline background showing optimal Zone 10b growing conditions — — Image © PlantReference.org 2026

Quick Answer

Plant tomatoes in San Diego February through April for summer harvest and September through October for winter crops. Zone 10b allows year-round growing.

TL;DR

San Diego's Zone 10b climate allows year-round tomato growing with optimal planting windows in February-April and September-October. Choose heat-tolerant varieties like Solanum lycopersicum 'Early Girl' and Solanum lycopersicum 'Sungold' for summer, cold-sensitive heirlooms like Solanum lycopersicum 'Brandywine' for winter growing. Start seeds indoors 6-8 weeks before transplanting for best results.

Frequently Asked Questions

When is the best time to plant tomatoes in San Diego?

The optimal planting windows in San Diego are February 15 through April 15 for spring crops and September 1 through October 31 for fall crops. San Diego's Zone 10b climate allows year-round growing, but these periods provide the best conditions for plant establishment and fruit development.

Can I grow tomatoes year-round in San Diego?

Yes, San Diego's Zone 10b climate supports year-round tomato production. However, plant different varieties for different seasons - heat-tolerant types like Solanum lycopersicum 'Early Girl' for summer and heat-sensitive heirlooms like Solanum lycopersicum 'Brandywine' for winter growing when temperatures stay between 60-75°F (15-24°C).

What tomato varieties grow best in San Diego's climate?

Solanum lycopersicum 'Early Girl' and Solanum lycopersicum 'Sungold' excel in San Diego's summer heat, while Solanum lycopersicum 'Brandywine'} and Solanum lycopersicum 'Cherokee Purple' perform beautifully during mild winters. Solanum lycopersicum 'Stupice' is unique - this cold-climate heirloom also shows surprising heat tolerance, making it suitable for year-round growing.

Do I need to protect tomatoes from frost in San Diego?

Occasional frost protection may be needed in inland areas during December and January. While San Diego's average last frost date is January 31, temperatures can drop to 32°F (0°C) or lower 2-3 times per winter. Keep frost blankets ready for predicted cold snaps, especially for winter-grown heirloom varieties.

How do I deal with San Diego's hard water affecting my tomato plants?

San Diego's mineral-rich water causes white buildup on leaves and soil salt accumulation over time. Flush container plants monthly with distilled water and apply gypsum annually to raised beds to improve soil structure. Consider a simple carbon filter for irrigation systems if growing in containers exclusively.

Why do my tomatoes get sunscald in San Diego?

Intense UV radiation in inland San Diego areas causes sunscald - white or yellow patches on exposed fruit. This is especially common on Solanum lycopersicum 'San Marzano'} with sparse foliage. Maintain adequate leaf cover through minimal pruning and use 30% shade cloth during July-August when UV index exceeds 8.

How should I water tomatoes during San Diego's wet winters?

Reduce watering significantly during San Diego's rainy season (November-March). Natural rainfall provides 8-12 inches (20-30cm) of water, often exceeding plant needs. Monitor soil moisture closely and only supplement irrigation during extended dry periods to prevent root rot in clay soils.

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Written By

Emma Chen

Emma runs a small succulent propagation business from her home in San Diego, shipping starter plants and cuttings across the country. She fell into succulents after college when she realized they were the only plants that survived her travel schedule—she was working as a travel nurse at the time. San Diego's mild, dry climate is ideal for outdoor succulent gardens, and Emma's front yard is a living catalog of over 200 varieties. She completed a certificate program in ornamental horticulture and writes about succulent care, propagation techniques, and drought-tolerant garden design. Her writing is calm and reassuring—she knows people feel bad about killing plants, and she wants them to stop worrying so much.