Frost Dates & Planting Calendar for Alton, TX

The average first fall frost in Alton, TX is December 28, and the average last spring frost is January 23, giving a growing season of about 340 days.

Plan your garden around Alton, TX's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.

Last Spring Frost

January 23

Safe Feb 27 Typical Jan 23 Risky Dec 22

First Fall Frost

December 28

Safe Dec 2 Typical Dec 28 Risky Feb 1

Growing Season

340 days

Typical last frost to typical first frost.

USDA Hardiness Zone

Zone 10a

Subtropical to frost-free — heat, not cold, is the main limit on what you can grow.

Data: NOAA station LA JOYA, TX US, 4.1 km away.

— days until the typical last spring frost

How Alton Compares

Alton's typical last spring frost (Jan 23) comes earlier than in 92% of the 258 Texas cities we track.
Its 340-day growing season is 81 days longer than the Texas median of 259 days.
Compared with Mission (8 km away), Alton's last spring frost comes 14 days later than Mission's, and its first fall frost arrives 361 days later.
August is the warmest month (average high 97°F) and January the coldest (average low 47°F).

Monthly Temperatures

Avg. high Avg. temp Avg. low

Planting Calendar

Vegetables
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Tomato	Nov 28 – Dec 12	—	Jan 30 – Feb 6	—	60–85 days	Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed.
Pepper	Nov 14 – Nov 28	—	Jan 30 – Feb 13	—	60–90 days	Slow to germinate; start indoors 8-10 weeks before last frost. Transplant only once nights stay above 55F, 1-3 weeks after last frost.
Eggplant	Nov 14 – Nov 28	—	Feb 6 – Feb 13	—	65–85 days	Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant.
Cucumber	Dec 26 – Jan 2	Jan 30 – Feb 6	Jan 30 – Feb 6	—	50–65 days	Can be started indoors 3-4 weeks before transplanting, or direct-sown 1-2 weeks after last frost once soil is warm.
Zucchini	Jan 2 – Jan 9	Jan 30 – Feb 13	Jan 30 – Feb 6	—	45–55 days	Fast-growing squash; direct sow 1-3 weeks after last frost, or start indoors 2-3 weeks early for a head start.
Winter Squash	Dec 26 – Jan 2	Jan 30 – Feb 13	Jan 30 – Feb 6	—	80–110 days	Long season; direct sow after soil warms, or start indoors 3-4 weeks before last frost in short-season climates.
Pumpkin	—	Jan 30 – Feb 13	—	—	90–120 days	Direct sow 1-3 weeks after last frost; back-time from your first fall frost so the 90-120 day maturity window lands before it.
Watermelon	Dec 26 – Jan 2	—	Feb 6 – Feb 13	—	70–90 days	Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost.
Cantaloupe	Dec 26 – Jan 2	—	Feb 6 – Feb 13	—	70–90 days	Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting.
Corn	—	Jan 23 – Feb 6	—	—	60–100 days	Direct sow at last frost to 2 weeks after, once soil reaches 60F; does not transplant well. Succession sow every 2 weeks.
Green Bean	—	Jan 23 – Feb 6	—	—	50–65 days	Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush.
Pea	—	Dec 12 – Dec 26	—	—	55–70 days	Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked.
Lettuce	—	Dec 26 – Jan 9	—	Nov 2 – Nov 16	45–60 days	Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts.
Spinach	—	Dec 12 – Dec 26	—	Nov 2 – Nov 16	40–50 days	Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked.
Kale	—	Dec 26 – Jan 9	—	Oct 19 – Nov 2	50–65 days	Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants.
Arugula	—	Dec 26 – Jan 9	—	Nov 16 – Nov 23	30–40 days	Fast-growing, cold-tolerant green; direct sow 2-4 weeks before last frost, succession sow every 2-3 weeks.
Swiss Chard	—	Jan 2 – Jan 16	—	—	50–60 days	Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too.
Broccoli	Dec 5 – Dec 19	—	Jan 2 – Jan 9	Oct 26 – Nov 2	55–80 days	Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost).
Cauliflower	Dec 5 – Dec 19	—	Jan 9 – Jan 16	Oct 19 – Oct 26	55–85 days	Fussier than broccoli about temperature swings; start indoors 5-7 weeks before last frost, transplant 1-2 weeks before last frost.
Cabbage	Dec 5 – Dec 19	—	Dec 26 – Jan 9	Oct 19 – Nov 2	60–100 days	Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost.
Brussels Sprouts	Dec 5 – Dec 19	—	Jan 2 – Jan 16	—	90–110 days	Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost.
Carrot	—	Dec 26 – Jan 9	—	Oct 5 – Oct 19	60–80 days	Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked.
Beet	—	Dec 26 – Jan 9	—	Oct 19 – Nov 2	50–65 days	Direct sow 2-4 weeks before last frost; tolerates light frost.
Radish	—	Dec 19 – Jan 2	—	Nov 16 – Nov 30	22–30 days	Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked.
Turnip	—	Dec 26 – Jan 9	—	Oct 19 – Nov 2	40–60 days	Cold-hardy; direct sow 2-4 weeks before last frost.
Onion	Nov 14 – Nov 28	—	Dec 26 – Jan 9	—	90–120 days	Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings.
Garlic	—	—	—	Nov 30 – Dec 14	240–270 days	Fall-planted crop only; not planted in spring in most climates.
Potato	—	Dec 26 – Jan 9	—	—	70–120 days	Plant seed potatoes 2-4 weeks before last frost, as soon as soil can be worked and is above 45F; light frost on emerging foliage is usually tolerated.
Sweet Potato	—	—	Feb 6 – Feb 20	—	90–120 days	Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive.
Asparagus	—	—	Dec 26 – Jan 9	—	730–1095 days	Perennial; plant crowns 2-4 weeks before last frost as soon as soil can be worked. Takes 2-3 years to full production.

Herbs
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Basil	Dec 12 – Dec 19	—	Jan 30 – Feb 6	—	50–70 days	Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm.
Cilantro	—	Jan 2 – Jan 16	—	Nov 2 – Nov 16	45–70 days	Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring.
Parsley	Nov 28 – Dec 12	—	Jan 9 – Jan 16	—	70–90 days	Slow to germinate; start indoors 6-8 weeks before last frost, transplant 1-2 weeks before last frost (biennial, cold-tolerant).
Dill	—	Jan 2 – Jan 16	—	—	40–60 days	Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer.
Oregano	Nov 28 – Dec 12	—	Jan 23 – Jan 30	—	80–90 days	Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date.
Thyme	Nov 28 – Dec 12	—	Jan 23 – Jan 30	—	85–95 days	Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost.

Flowers
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Sunflower	—	Jan 30 – Feb 13	—	—	70–100 days	Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting.
Zinnia	Dec 26 – Jan 2	Jan 30 – Feb 13	Jan 30 – Feb 6	—	60–70 days	Frost-tender; direct sow 1-3 weeks after last frost, or start indoors 3-4 weeks early for earlier blooms.
Marigold	Dec 12 – Dec 26	—	Jan 30 – Feb 6	—	45–60 days	Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed.
Cosmos	Dec 26 – Jan 2	Jan 30 – Feb 13	Jan 30 – Feb 6	—	60–90 days	Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early.
Nasturtium	—	Jan 30 – Feb 13	—	—	50–65 days	Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed.
Dahlia	—	—	Jan 30 – Feb 13	—	90–120 days	Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive.

Date ranges are estimates based on university extension guidelines and this city's NOAA frost normals — not a guarantee. Scroll to see all columns on narrow screens.

Frequently Asked Questions

When is the last frost in Alton, TX?

Based on 1991–2020 NOAA climate normals for the LA JOYA, TX US station, the last spring frost in Alton typically falls around January 23. A cautious gardener might wait until February 27 (only a 10% chance of a later frost), while December 22 marks an earlier, higher-risk planting date.

When is the first frost in Alton, TX in fall?

The first fall frost in Alton typically arrives around December 28. To stay safe, assume frost could start as early as December 2; in milder years it can hold off until February 1.

How long is the growing season in Alton, TX?

Alton's average frost-free growing season is about 340 days, running from the typical last spring frost (January 23) to the typical first fall frost (December 28).

What USDA hardiness zone is Alton, TX in?

Alton, TX is in USDA plant hardiness zone 10a, per the USDA's 2023 Plant Hardiness Zone Map. Subtropical to frost-free — heat, not cold, is the main limit on what you can grow.