Planting Guides

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

San Francisco, California

USDA Zone 10a

Last Frost: Jan 15

Last updated: October 30, 2025

Plant kale year-round in San Francisco's ideal Zone 10a climate. Best planting times: September-November for winter harvest, March-May for spring.

DDavid Kim

October 30, 2025

Kale plants growing in San Francisco urban garden with city skyline showing ideal Zone 10a growing conditions — — Image © PlantReference.org 2026

Quick Answer

Plant kale in San Francisco September through November for winter harvest, March through May for spring crops. Zone 10a's mild climate allows nearly year-round growing.

TL;DR

San Francisco's Zone 10a climate allows year-round kale growing with ideal cool, foggy summers. Best planting times are September-November for peak winter flavor and March-May for spring harvest. All kale varieties thrive in San Francisco's mild temperatures, with Brassica oleracea 'Lacinato' and Brassica oleracea 'Red Russian' performing exceptionally well in the coastal fog belt.

Frequently Asked Questions

When is the absolute best time to plant kale in San Francisco?

September through November is optimal for San Francisco kale planting. Plants started during this window mature during our coolest, most humid months when flavor peaks and growth conditions are ideal. Fall-planted kale often produces continuously through the following spring, giving you the longest harvest window. March through May works as a secondary planting time, but fall consistently delivers superior results.

Can I really grow kale year-round in San Francisco?

Yes, San Francisco's Zone 10a climate allows nearly continuous kale production. Our mild winters rarely drop below 35°F (2°C), and summer temperatures seldom exceed 75°F (24°C) consistently. With succession planting every 8-10 weeks, you can maintain fresh kale year-round. However, winter growth is slower, and summer plants may be slightly more bitter than those grown during cooler months.

Which kale variety performs best in San Francisco's foggy conditions?

Brassica oleracea 'Lacinato' excels in San Francisco's fog belt. This variety actually thrives in the consistent moisture and cool temperatures that fog provides. The thick, textured leaves handle humidity well without developing fungal issues. Brassica oleracea 'Red Russian' is also excellent for quick succession crops. Avoid varieties that struggle with constant moisture if you're in persistently foggy neighborhoods like the Sunset or Richmond.

How do I prevent my kale from bolting during San Francisco summers?

Bolting is rarely an issue in San Francisco due to our naturally cool summers. Unlike inland California where summer heat triggers flowering, San Francisco's marine layer keeps temperatures moderate. If you're in a warmer microclimate like the Mission District, provide afternoon shade and consistent water during heat waves. Choose bolt-resistant varieties like Brassica oleracea 'Red Russian' for summer plantings.

What's the biggest challenge growing kale in San Francisco?

Slug and snail damage is the primary challenge for San Francisco kale growers. Our moist climate creates perfect conditions for these pests, which can destroy young plants overnight. Use copper barriers, diatomaceous earth, and beer traps for organic control. Hand-picking during early morning hours when slugs are active is also effective. The humid conditions can occasionally cause aphid buildup, but this is easily managed with beneficial insects and proper plant spacing.

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Tagged with

#kale planting #San Francisco gardening #Zone 10a vegetables #year-round kale #coastal gardening #cool season crops #urban gardening #Bay Area vegetables #organic kale growing #fog belt gardening

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.