GrowZone

ZIP 78205 planting calendar

When to plant spinach in San Antonio, TX - Zone 9a

In ZIP 78205, plant spinach around Feb 1; this uses the San Antonio frost station, USDA zone 9a, and spinach timing rules.

Your San Antonio calendar has a 264-day estimated frost-free season. This estimate uses the representative San Antonio frost station, USDA zone 9a, and spinach timing rules.

Source: san-antonio-intl frost station, USDA zone 9a, 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 9a San Antonio frost station Texas A&M AgriLife Extension Updated 2026-06-28
Read the method

Answer first

When to start spinach seeds indoors in San Antonio

In ZIP 78205, spinach is usually direct-sown around Feb 1 instead of started indoors.

Spinach is normally direct-sown in San Antonio. Use around Feb 1 as the outdoor planting window for ZIP 78205.

Seed starting schedule

Spinach dates for San Antonio, TX

StepDateHow to use it
Direct SowFebruary 1, 2026Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in San Antonio?

San Antonio (ZIP 78205) has an average last spring frost around Mar 1.

First frost

When is the first frost in San Antonio?

The average first fall frost is around Nov 20, giving about 264 frost-free days.

Season map

Spinach windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Direct sow
Feb 1
Harvest
Mar 18
Frost watch
Oct 6

Reminder workflow

Every date has a next action

Direct sow spinachFeb 1
Last frost windowMar 1
First spinach harvest windowMar 18
Last spinach sowing targetOct 6
SignalValueWhy it matters
Last frost estimateMarch 1, 2026Warm-season transplant risk starts falling after this window.
First frost estimateNovember 20, 2026Fall planting counts backward from this date.
Season length264 daysLonger seasons can support succession crops.
Spacing4-6 inAirflow and root space affect yield.
Soil temperature40 F+Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

San Antonio frost history and USDA zone 9a shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

Texas A&M AgriLife Extension 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

Spinach timing notes

Plant early and again in late summer for fall leaves. Spinach prefers sun to part shade, 4-6 in spacing, and soil near 40 F+.

For fall, count backward from Nov 20. A conservative last sowing target is around Oct 6.