USDA Zone 8b Planting Calendar (2026)
Zone 8b (15 to 20°F) has an average last spring frost on Mar 15 and first fall frost on Nov 20 — about 250 growing days. Typical areas: Austin TX, Savannah GA.
How to use the zone 8b planting calendar
Every planting date on this page is calculated from zone 8b's average frost dates. Because your last spring frost lands around Mar 15 and your first fall frost around Nov 20, you have roughly 250 frost-free days to work with — a long growing season. The table below lists, for each of 20 common vegetables, when to start seeds indoors, when to sow or transplant outdoors, and when you can expect your first harvest.
Frost dates are averages, not guarantees. In a cold year the last frost can arrive 1-2 weeks later, so keep row covers handy for tender seedlings in Mar. Click any vegetable name to open a detailed zone 8b guide with spacing, companions, container tips and troubleshooting.
Cool-season crops for zone 8b
These tolerate light frost and go out first, 2-4 weeks before your Mar 15 last frost, and again in late summer for a fall crop: lettuce, carrot, broccoli, spinach, kale, onion, garlic, potato, peas, radish, beet, cabbage, cauliflower.
Warm-season crops for zone 8b
These need warm soil and frost-free weather, so plant them after Mar 15: tomato, pepper, cucumber, corn, bush beans, summer squash, zucchini. In a long season, start the slowest ones indoors to be sure they ripen before Nov.
| Vegetable | Start Indoors | Sow / Transplant | Harvest From |
|---|---|---|---|
| Beet | — | Feb 15 | Apr 11 |
| 🥦 Broccoli | Feb 8 | Mar 1 | May 5 |
| 🫘 Bush Beans | — | Mar 22 | May 16 |
| 🥬 Cabbage | Feb 1 | Mar 1 | May 20 |
| 🥕 Carrot | — | Feb 22 | May 3 |
| 🥦 Cauliflower | Feb 1 | Mar 1 | May 15 |
| 🌽 Corn | — | Mar 29 | Jun 17 |
| 🥒 Cucumber | Feb 22 | Mar 29 | May 23 |
| 🧄 Garlic | — | Aug 30 | Apr 27 |
| 🥬 Kale | Feb 8 | Feb 22 | Apr 18 |
| 🥬 Lettuce | Feb 15 | Feb 22 | Apr 8 |
| 🧅 Onion | Jan 4 | Feb 15 | May 26 |
| 🟢 Peas | — | Feb 1 | Apr 2 |
| 🫑 Pepper | Jan 18 | Mar 29 | Jun 7 |
| 🥔 Potato | — | Mar 1 | May 30 |
| 🌶️ Radish | — | Feb 15 | Mar 15 |
| 🍃 Spinach | — | Feb 8 | Mar 20 |
| 🎃 Summer Squash | Feb 22 | Mar 22 | May 11 |
| 🍅 Tomato | Feb 1 | Mar 22 | Jun 5 |
| 🥒 Zucchini | Feb 22 | Mar 22 | May 11 |
Spring, summer and fall planting in zone 8b
Spring (Mar): As soon as the soil can be worked, direct sow hardy cool-season crops and set out frost-tolerant transplants. This is your window for peas, lettuce, spinach and the brassicas before summer heat arrives.
Early summer (after Mar 15): Once frost danger passes and soil warms past 60°F, transplant tomatoes, peppers and squash and direct sow beans and cucumbers. This is the heart of the zone 8b growing season.
Late summer to fall (before Nov 20):Sow a second round of quick cool-season crops for a fall harvest. Count back each crop's days-to-harvest from Nov 20 to find the latest safe sowing date, and use row covers to stretch the season a few extra weeks.
Zone 8b planting FAQ
What planting zone is Austin TX?
Areas like Austin TX, Savannah GA fall in USDA hardiness zone 8b, defined by an average annual minimum temperature of 15 to 20°F. Your average last spring frost is around Mar 15 and your first fall frost around Nov 20.
When is the last frost in zone 8b?
The average last spring frost in zone 8b is around Mar 15. Wait until after this date before transplanting warm-season crops like tomatoes, peppers and squash. Cool-season crops can go out 2-4 weeks earlier because they tolerate light frost.
How long is the growing season in zone 8b?
Zone 8b has roughly 250 frost-free days between the last spring frost (Mar 15) and first fall frost (Nov 20). That is a long season — long enough for two or even three successive harvests of fast crops.
What vegetables grow best in zone 8b?
Reliable choices for zone 8b include cool-season crops such as lettuce, carrot, broccoli, spinach planted in early spring, and warm-season crops such as tomato, pepper, cucumber, corn planted after the last frost. See the full table below for exact dates.
Can I grow a fall garden in zone 8b?
Yes. With a first frost around Nov 20, you can plant a second round of quick cool-season crops in mid to late summer. Count back the days-to-harvest from Nov 20 to find your fall planting date.
When should I start seeds indoors in zone 8b?
Most warm-season seedlings are started indoors 6-8 weeks before the last frost — that means roughly Mar for zone 8b. Tomatoes, peppers and eggplant benefit most from an indoor head start in this zone.