USDA Zone 4b planting calendar
In USDA Zone 4b, the average last spring frost is around 05/10 and the first fall frost around 09/30, giving roughly a 141-day growing season. Plant cool-season crops from late winter; warm-season crops after the last frost.
Last frost ~05/10
First frost ~09/30
~141-day season
51 NOAA stations
The year in Zone 4b
What to plant now (August)
Spinach
Sow for fall harvest
Radishes
Sow for fall harvest
All crops in Zone 4b
| Crop | Start indoors | Transplant / sow | Sow for fall |
|---|---|---|---|
| Tomatoes | April 9 – April 16 | May 14 – May 28 | — |
| Peppers | March 29 | May 17 – May 31 | — |
| Eggplant | April 2 – April 16 | May 21 – June 4 | — |
| Basil | April 9 | May 14 – May 28 | — |
| Broccoli | March 22 – March 29 | April 12 – April 26 | June 21 – July 5 |
| Cabbage | March 1 – March 15 | April 5 – April 19 | May 12 – May 26 |
| Cauliflower | March 15 – March 29 | April 19 – May 3 | June 26 – July 10 |
| Brussels Sprouts | March 8 – March 22 | April 12 – April 26 | — |
| Kale | March 1 – March 15 | April 5 – April 19 | July 1 – July 15 |
| Lettuce | March 12 – March 19 | April 9 – April 23 | June 16 – June 30 |
| Spinach | — | April 2 – April 16 | July 26 – August 9 |
| Onions | February 1 – February 15 | April 5 – April 19 | — |
| Leeks | February 8 – February 22 | April 12 – April 26 | — |
| Swiss Chard | March 15 – March 22 | April 19 – May 3 | — |
| Radishes | — | April 12 – April 26 | August 10 – August 24 |
| Turnips | — | April 12 – April 26 | July 11 – July 25 |
| Beets | — | April 19 – May 3 | July 6 – July 20 |
| Carrots | — | May 3 – May 17 | June 6 – June 20 |
| Peas | — | March 29 – April 12 | July 1 – July 15 |
| Beans | — | May 10 – May 24 | — |
| Sweet Corn | — | May 10 – May 24 | — |
| Cucumbers | April 23 – April 30 | May 14 – May 28 | — |
| Summer Squash & Zucchini | April 26 – May 3 | May 17 – May 31 | — |
| Winter Squash | April 26 – May 3 | May 17 – May 31 | — |
| Pumpkins | April 26 – May 3 | May 17 – May 31 | — |
| Melons | April 26 – May 3 | May 17 – May 31 | — |
| Okra | April 19 – May 3 | May 24 – June 7 | — |
| Potatoes | — | April 23 – May 7 | — |
| Parsley | February 12 – February 19 | April 16 – April 30 | — |
| Collards | March 1 – March 15 | April 5 – April 19 | June 16 – June 30 |
| Watermelon | April 26 – May 3 | May 17 – May 31 | — |
| Sweet Potatoes | — | May 14 – May 28 | — |
| Celery | February 22 – March 8 | May 10 – May 24 | — |
| Kohlrabi | March 1 – March 15 | April 5 – April 19 | — |
| Artichoke | February 15 – March 15 | May 3 – May 17 | — |
| Asparagus | — | April 9 – April 23 | — |
| Cilantro | — | May 10 – May 24 | — |
| Dill | — | April 23 – May 7 | — |
| Oregano | March 8 – March 22 | May 10 – May 24 | — |
| Sage | March 22 – April 5 | May 10 – May 24 | — |
| Thyme | March 8 – March 22 | May 10 – May 24 | — |
Fall bulb planting in Zone 4b
| Crop | Plant cloves (fall) | Harvest |
|---|---|---|
| Garlic | October 4 – October 18 | Following summer |
Last verified 2026-08-28. Frost: NOAA NCEI 1991–2020 Climate Normals. Zone: USDA 2023 Plant Hardiness Zone Map (PRISM-derived). Planting rules: UNH Extension, Johnny's Selected Seeds, UGA Extension.