USDA Zone 10b Planting Calendar (2026)
Zone 10b (35 to 40°F) has an average last spring frost on Jan 15 and first fall frost on Dec 31 — about 350 growing days. Typical areas: Key West FL, coastal So-Cal.
How to use the zone 10b planting calendar
Every planting date on this page is calculated from zone 10b's average frost dates. Because your last spring frost lands around Jan 15 and your first fall frost around Dec 31, you have roughly 350 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 Jan. Click any vegetable name to open a detailed zone 10b guide with spacing, companions, container tips and troubleshooting.
Cool-season crops for zone 10b
These tolerate light frost and go out first, 2-4 weeks before your Jan 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 10b
These need warm soil and frost-free weather, so plant them after Jan 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 Dec.
| Vegetable | Start Indoors | Sow / Transplant | Harvest From |
|---|---|---|---|
| Beet | — | Dec 18 | Feb 11 |
| 🥦 Broccoli | Dec 11 | Jan 1 | Mar 7 |
| 🫘 Bush Beans | — | Jan 22 | Mar 18 |
| 🥬 Cabbage | Dec 4 | Jan 1 | Mar 22 |
| 🥕 Carrot | — | Dec 25 | Mar 5 |
| 🥦 Cauliflower | Dec 4 | Jan 1 | Mar 17 |
| 🌽 Corn | — | Jan 29 | Apr 19 |
| 🥒 Cucumber | Dec 25 | Jan 29 | Mar 25 |
| 🧄 Garlic | — | Jul 2 | Feb 27 |
| 🥬 Kale | Dec 11 | Dec 25 | Feb 18 |
| 🥬 Lettuce | Dec 18 | Dec 25 | Feb 8 |
| 🧅 Onion | Nov 6 | Dec 18 | Mar 28 |
| 🟢 Peas | — | Dec 4 | Feb 2 |
| 🫑 Pepper | Nov 20 | Jan 29 | Apr 9 |
| 🥔 Potato | — | Jan 1 | Apr 1 |
| 🌶️ Radish | — | Dec 18 | Jan 15 |
| 🍃 Spinach | — | Dec 11 | Jan 20 |
| 🎃 Summer Squash | Dec 25 | Jan 22 | Mar 13 |
| 🍅 Tomato | Dec 4 | Jan 22 | Apr 7 |
| 🥒 Zucchini | Dec 25 | Jan 22 | Mar 13 |
Spring, summer and fall planting in zone 10b
Spring (Jan): 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 Jan 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 10b growing season.
Late summer to fall (before Dec 31):Sow a second round of quick cool-season crops for a fall harvest. Count back each crop's days-to-harvest from Dec 31 to find the latest safe sowing date, and use row covers to stretch the season a few extra weeks.
Zone 10b planting FAQ
What planting zone is Key West FL?
Areas like Key West FL, coastal So-Cal fall in USDA hardiness zone 10b, defined by an average annual minimum temperature of 35 to 40°F. Your average last spring frost is around Jan 15 and your first fall frost around Dec 31.
When is the last frost in zone 10b?
The average last spring frost in zone 10b is around Jan 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 10b?
Zone 10b has roughly 350 frost-free days between the last spring frost (Jan 15) and first fall frost (Dec 31). That is a long season — long enough for two or even three successive harvests of fast crops.
What vegetables grow best in zone 10b?
Reliable choices for zone 10b 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 10b?
Yes. With a first frost around Dec 31, you can plant a second round of quick cool-season crops in mid to late summer. Count back the days-to-harvest from Dec 31 to find your fall planting date.
When should I start seeds indoors in zone 10b?
Most warm-season seedlings are started indoors 6-8 weeks before the last frost — that means roughly Jan for zone 10b. Tomatoes, peppers and eggplant benefit most from an indoor head start in this zone.