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When to plant in South Houston, TX

USDA Zone 9b

Everything below — frost dates, hardiness zone, and what to plant when in South Houston, Texas — is derived from the closest NOAA station with complete climate normals.

South Houston enjoys a long ~332-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. Zone 9b is warm enough that South Houston can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · HOUSTON HOBBY AP · 5.8 km
Last spring frost
January 30
50% chance · 32°F
First fall frost
December 28
50% chance · 32°F
Growing season
332 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for South HoustonA year-band showing 32°F frost risk from January to December for South Houston: last spring frost around January 30, first fall frost around December 28, about 332 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average first fall frost in South Houston is now 8 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

HOUSTON HOBBY AP · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are South Houston’s own odds, recorded at HOUSTON HOBBY AP.

Frost-probability curves for South HoustonProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 30 and the first fall frost around December 28, giving about 332 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMar 12Feb 17Jan 20Nov 15Dec 4Jan 3
32°FMar 1Jan 30Dec 29Nov 27Dec 28Jan 27
28°FFeb 17Jan 17Dec 22Dec 12Jan 8Feb 4

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19

Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.

Add the next planting windows to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in South Houston, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 16 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

HOUSTON HOBBY AP
Primary
6 km · 13 m elevation
SPRING
Jan 30
FALL
Dec 28
HOUSTON-PORT
11 km · 6 m elevation
SPRING
Feb 2
FALL
Dec 25
HOUSTON CLOVER FLD
16 km · 13 m elevation
SPRING
Jan 31
FALL
Dec 27

South Houston planting FAQ

When is the last spring frost in South Houston, TX?

South Houston's average last spring frost falls near January 30 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.

When is the first fall frost in South Houston, TX?

Expect South Houston's first fall frost near December 28 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is South Houston in?

South Houston is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.

How long is the growing season in South Houston?

There are roughly 332 frost-free days in South Houston (a long growing season), running from the average last frost around January 30 to the first fall frost near December 28.

When should I plant tomatoes in South Houston?

In South Houston, start tomato seeds indoors around December 5–December 19, then transplant seedlings outdoors around February 6 once the danger of frost has passed.

Planting reminders

Never miss a window in South Houston

An email when it’s time to start seeds, transplant, and sow — timed to South Houston’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at HOUSTON HOBBY AP, 6 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in South Houston, TX — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00012918. Retrieved from https://blissgarden.com/texas/south-houston.