USDA Zone 4a planting calendar
In USDA Zone 4a, the average last spring frost is around 05/14 and the first fall frost around 09/27, giving roughly a 134-day growing season. Plant cool-season crops from late winter; warm-season crops after the last frost.
Last frost ~05/14
First frost ~09/27
~134-day season
26 NOAA stations
The year in Zone 4a
What to plant now (September)
No sowing or transplanting tasks land in September for this zone from our current crop list.
All crops in Zone 4a
| Crop | Start indoors | Transplant / sow | Sow for fall |
|---|---|---|---|
| Tomatoes | April 13 – April 20 | May 18 – June 1 | — |
| Peppers | April 2 | May 21 – June 4 | — |
| Eggplant | April 6 – April 20 | May 25 – June 8 | — |
| Basil | April 13 | May 18 – June 1 | — |
| Broccoli | March 26 – April 2 | April 16 – April 30 | June 18 – July 2 |
| Cabbage | March 5 – March 19 | April 9 – April 23 | May 9 – May 23 |
| Cauliflower | March 19 – April 2 | April 23 – May 7 | June 23 – July 7 |
| Brussels Sprouts | March 12 – March 26 | April 16 – April 30 | — |
| Kale | March 5 – March 19 | April 9 – April 23 | June 28 – July 12 |
| Lettuce | March 16 – March 23 | April 13 – April 27 | June 13 – June 27 |
| Spinach | — | April 6 – April 20 | July 23 – August 6 |
| Onions | February 5 – February 19 | April 9 – April 23 | — |
| Leeks | February 12 – February 26 | April 16 – April 30 | — |
| Swiss Chard | March 19 – March 26 | April 23 – May 7 | — |
| Radishes | — | April 16 – April 30 | August 7 – August 21 |
| Turnips | — | April 16 – April 30 | July 8 – July 22 |
| Beets | — | April 23 – May 7 | July 3 – July 17 |
| Carrots | — | May 7 – May 21 | June 3 – June 17 |
| Peas | — | April 2 – April 16 | June 28 – July 12 |
| Beans | — | May 14 – May 28 | — |
| Sweet Corn | — | May 14 – May 28 | — |
| Cucumbers | April 27 – May 4 | May 18 – June 1 | — |
| Summer Squash & Zucchini | April 30 – May 7 | May 21 – June 4 | — |
| Winter Squash | April 30 – May 7 | May 21 – June 4 | — |
| Pumpkins | April 30 – May 7 | May 21 – June 4 | — |
| Melons | April 30 – May 7 | May 21 – June 4 | — |
| Okra | April 23 – May 7 | May 28 – June 11 | — |
| Potatoes | — | April 27 – May 11 | — |
| Parsley | February 16 – February 23 | April 20 – May 4 | — |
| Collards | March 5 – March 19 | April 9 – April 23 | June 13 – June 27 |
| Watermelon | April 30 – May 7 | May 21 – June 4 | — |
| Sweet Potatoes | — | May 18 – June 1 | — |
| Celery | February 26 – March 12 | May 14 – May 28 | — |
| Kohlrabi | March 5 – March 19 | April 9 – April 23 | — |
| Artichoke | February 19 – March 19 | May 7 – May 21 | — |
| Asparagus | — | April 13 – April 27 | — |
| Cilantro | — | May 14 – May 28 | — |
| Dill | — | April 27 – May 11 | — |
| Oregano | March 12 – March 26 | May 14 – May 28 | — |
| Sage | March 26 – April 9 | May 14 – May 28 | — |
| Thyme | March 12 – March 26 | May 14 – May 28 | — |
Fall bulb planting in Zone 4a
| Crop | Plant cloves (fall) | Harvest |
|---|---|---|
| Garlic | October 1 – October 15 | Following summer |
Last verified 2026-09-12. 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.