When should I plant lettuce in ZIP 92101?

In ZIP 92101, the main lettuce target is around Jan 16, based on the representative San Diego frost station and USDA zone 10b.

When should I start lettuce seeds indoors in 92101?

Start lettuce seeds indoors in ZIP 92101 around Jan 2, about 28 days before the Jan 30 last-frost estimate.

Is this a guaranteed planting date?

No. GrowZone uses frost-date estimates, hardiness zones, and crop timing rules for planning. Local microclimates and current weather can shift the right date.

ZIP 92101 planting calendar

When to plant lettuce in San Diego, CA - Zone 10b

Q: When is the first frost in San Diego?

San Diego (ZIP 92101) has an average first fall frost around Dec 15, leaving about 319 frost-free days.

In ZIP 92101, plant lettuce around Jan 16; this uses the San Diego frost station, USDA zone 10b, and lettuce timing rules.

Your San Diego calendar has a 319-day estimated frost-free season. This estimate uses the representative San Diego frost station, USDA zone 10b, and lettuce timing rules.

Source: san-diego-lindbergh frost station, USDA zone 10b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

USDA zone 10b San Diego frost station University of California Agriculture and Natural Resources Updated 2026-06-28

Read the method

Answer first

When to start lettuce seeds indoors in San Diego

In ZIP 92101, start lettuce seeds indoors around Jan 2, about 28 days before the Jan 30 last-frost estimate.

Start lettuce seeds indoors in San Diego around Jan 2, about 28 days before the Jan 30 last-frost estimate.

Seed starting schedule

Lettuce dates for San Diego, CA

Step	Date	How to use it
Start Indoors	January 2, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	January 16, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	January 16, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in San Diego?

San Diego (ZIP 92101) has an average last spring frost around Jan 30.

First frost

When is the first frost in San Diego?

The average first fall frost is around Dec 15, giving about 319 frost-free days.

Season map

Lettuce windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Jan 2

Direct sow

Jan 16

Transplant

Jan 16

Harvest

Mar 12

Frost watch

Oct 21

Reminder workflow

Every date has a next action

Start lettuce indoorsJan 2

Direct sow lettuceJan 16

Transplant lettuceJan 16

Last frost windowJan 30

First lettuce harvest windowMar 12

Last lettuce sowing targetOct 21

Signal	Value	Why it matters
Last frost estimate	January 30, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	December 15, 2026	Fall planting counts backward from this date.
Season length	319 days	Longer seasons can support succession crops.
Spacing	8-12 in	Airflow and root space affect yield.
Soil temperature	40 F+	Seeds and transplants stall in cold soil.

GrowZone may earn from qualifying seed or supply links when real affiliate IDs are configured. No monetized links are active without disclosure.

Local data

Why this date changes by ZIP

San Diego frost history and USDA zone 10b shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

University of California Agriculture and Natural Resources is the kind of local source to verify against when a crop is expensive, weather is unusual, or your yard has a cold pocket.

Crop note

Lettuce timing notes

Succession sow every 10-14 days while weather is cool. Lettuce prefers sun to part shade, 8-12 in spacing, and soil near 40 F+.

For fall, count backward from Dec 15. A conservative last sowing target is around Oct 21.