Zone 3a planting calendar
Very short, cold season. Start most warm crops indoors and pick fast-maturing varieties.
Coldest temps-40 to -35°F
Avg. last spring frostMay 25
Avg. first fall frostSep 8
Open the interactive calendar for Zone 3a →
The growing season in Zone 3a
Zone 3a has a coldest-winter range of -40 to -35°F and an average frost-free growing season of roughly 106 days — from the last spring frost around May 25 to the first fall frost around Sep 8. That is a short season — lean on cold-hardy crops and quick-maturing varieties, and give tender, long-season crops a generous indoor head start so they can finish in time.
The practical rhythm here is simple. Cool-season crops — peas, spinach, lettuce, radishes, and the brassicas — can go out around the last-frost date and again for a fall crop. Frost-tender crops like tomatoes, peppers, squash, and basil wait until after May 25, and the longer-season ones among them (melons, winter squash, full-size tomatoes) are the plants to watch against the 106-day window. Start those indoors on the schedule below so they have time to finish before fall frost returns.
What to plant in Zone 3a
Every crop below is timed to Zone 3a's frost dates. Follow a crop link for its full growing profile across all zones, or open the interactive calendar for the month-by-month view.
| Crop | When to plant |
|---|---|
| Tomato | Start seeds indoors Apr 6–Apr 20 Transplant outdoors Jun 1–Jun 8 |
| Pepper | Start seeds indoors Mar 23–Apr 6 Transplant outdoors Jun 8–Jun 15 |
| Lettuce | Direct sow outdoors Apr 27–May 25 Direct sow outdoors Jul 14–Jul 28 |
| Carrot | Direct sow outdoors May 4–Jun 8 Direct sow outdoors Jun 30–Jul 14 |
| Bush Bean | Direct sow outdoors May 25–Jun 22 |
| Cucumber | Start seeds indoors May 4–May 11 Transplant outdoors Jun 1–Jun 8 Direct sow outdoors Jun 1–Jun 15 |
| Zucchini | Direct sow outdoors May 25–Jun 15 |
| Spinach | Direct sow outdoors Apr 13–May 11 Direct sow outdoors Jul 14–Aug 4 |
| Kale | Start seeds indoors Apr 13–Apr 27 Transplant outdoors May 11–May 25 Direct sow outdoors May 11–Jun 8 Direct sow outdoors Jun 16–Jul 14 |
| Pea | Direct sow outdoors Apr 13–May 4 |
| Basil | Start seeds indoors Apr 13–Apr 27 Transplant outdoors Jun 1–Jun 15 |
| Cilantro | Direct sow outdoors May 4–Jun 1 Direct sow outdoors Jul 14–Aug 4 |
| Broccoli | Start seeds indoors Apr 6–Apr 20 Transplant outdoors May 11–May 25 Direct sow outdoors Jun 2–Jun 23 |
| Cabbage | Start seeds indoors Mar 30–Apr 13 Transplant outdoors May 11–May 25 |
| Cauliflower | Start seeds indoors Apr 6–Apr 20 Transplant outdoors May 11–May 25 |
| Brussels Sprouts | Start seeds indoors Apr 13–Apr 27 Transplant outdoors May 18–Jun 1 |
| Onion | Start seeds indoors Mar 16–Mar 30 Transplant outdoors Apr 27–May 11 |
| Garlic | Direct sow outdoors Aug 11–Aug 25 |
| Beet | Direct sow outdoors Apr 27–May 25 Direct sow outdoors Jun 30–Jul 14 |
| Radish | Direct sow outdoors Apr 27–Jun 8 Direct sow outdoors Jul 14–Aug 11 |
| Swiss Chard | Direct sow outdoors May 11–Jun 8 |
| Potato | Direct sow outdoors May 11–Jun 8 |
| Sweet Corn | Direct sow outdoors May 25–Jun 15 |
| Eggplant | Start seeds indoors Mar 30–Apr 13 Transplant outdoors Jun 8–Jun 15 |
| Pumpkin | Direct sow outdoors May 25–Jun 15 |
| Winter Squash | Direct sow outdoors May 25–Jun 15 |
| Arugula | Direct sow outdoors Apr 27–May 25 Direct sow outdoors Jul 14–Aug 11 |
| Leek | Start seeds indoors Mar 16–Mar 30 Transplant outdoors Apr 27–May 11 |
| Turnip | Direct sow outdoors Apr 27–May 25 Direct sow outdoors Jul 14–Jul 28 |
| Kohlrabi | Direct sow outdoors Apr 27–May 25 Direct sow outdoors Jul 14–Jul 28 |
| Okra | Start seeds indoors Apr 27–May 11 Direct sow outdoors Jun 1–Jun 15 |
| Celery | Start seeds indoors Mar 16–Mar 30 Transplant outdoors May 18–Jun 1 |
| Collard Greens | Start seeds indoors Apr 13–Apr 27 Transplant outdoors May 11–May 25 Direct sow outdoors Jun 16–Jul 14 |
| Mustard Greens | Direct sow outdoors Apr 27–May 25 Direct sow outdoors Jul 14–Aug 4 |
| Bok Choy | Direct sow outdoors May 4–May 25 Direct sow outdoors Jul 14–Aug 4 |
| Fennel | Direct sow outdoors May 11–Jun 8 Direct sow outdoors Jun 30–Jul 14 |
| Sweet Potato | Transplant outdoors Jun 8–Jun 22 |
| Parsnip | Direct sow outdoors May 11–Jun 8 |
| Asparagus | Transplant outdoors Apr 27–May 11 |
| Parsley | Start seeds indoors Mar 30–Apr 13 Transplant outdoors May 11–May 25 Direct sow outdoors May 11–Jun 8 |
| Dill | Direct sow outdoors May 11–Jun 8 Direct sow outdoors Jul 14–Jul 28 |
| Chives | Start seeds indoors Mar 30–Apr 13 Transplant outdoors May 11–May 25 |
| Thyme | Start seeds indoors Mar 30–Apr 13 Transplant outdoors May 25–Jun 8 |
| Oregano | Start seeds indoors Mar 30–Apr 13 Transplant outdoors May 25–Jun 8 |
| Sage | Start seeds indoors Mar 30–Apr 13 Transplant outdoors May 25–Jun 8 |
| Rosemary | Start seeds indoors Mar 16–Mar 30 Transplant outdoors Jun 8–Jun 22 |
| Mint | Transplant outdoors May 25–Jun 8 |
| Lavender | Start seeds indoors Mar 16–Mar 30 Transplant outdoors May 25–Jun 8 |
| Chamomile | Direct sow outdoors May 11–Jun 8 |
| Lemon Balm | Start seeds indoors Mar 30–Apr 13 Transplant outdoors May 25–Jun 8 |
| Tarragon | Transplant outdoors May 25–Jun 8 |
| Strawberry | Transplant outdoors Apr 27–May 11 |
| Watermelon | Start seeds indoors Apr 27–May 11 Transplant outdoors Jun 8–Jun 15 Direct sow outdoors Jun 1–Jun 15 |
| Cantaloupe | Start seeds indoors Apr 27–May 11 Transplant outdoors Jun 8–Jun 15 Direct sow outdoors Jun 1–Jun 15 |
| Ground Cherry | Start seeds indoors Apr 6–Apr 20 Transplant outdoors Jun 1–Jun 8 |
| Blueberry | Transplant outdoors Apr 27–May 11 |
| Raspberry | Transplant outdoors Apr 20–May 4 |
| Blackberry | Transplant outdoors Apr 20–May 4 |
| Rhubarb | Transplant outdoors Apr 20–May 4 |
| Currant | Transplant outdoors Apr 13–May 4 |
| Gooseberry | Transplant outdoors Apr 13–May 4 |
| Marigold | Start seeds indoors Apr 13–Apr 27 Transplant outdoors Jun 1–Jun 8 Direct sow outdoors May 25–Jun 8 |
| Zinnia | Start seeds indoors Apr 27–May 11 Transplant outdoors Jun 1–Jun 8 Direct sow outdoors May 25–Jun 8 |
| Sunflower | Direct sow outdoors May 25–Jun 15 |
| Cosmos | Direct sow outdoors May 25–Jun 8 |
| Nasturtium | Direct sow outdoors May 25–Jun 8 |
| Sweet Pea | Direct sow outdoors Apr 13–May 4 |
| Snapdragon | Start seeds indoors Mar 30–Apr 13 Transplant outdoors May 11–May 25 |
| Pansy | Start seeds indoors Mar 16–Mar 30 Transplant outdoors Apr 27–May 11 |
| Dahlia | Start seeds indoors Apr 27–May 11 Transplant outdoors Jun 1–Jun 8 |
| Calendula | Direct sow outdoors May 11–Jun 8 Direct sow outdoors Jul 14–Jul 28 |
| Poppy | Direct sow outdoors Apr 13–May 11 |
| Cornflower | Direct sow outdoors Apr 27–May 18 Direct sow outdoors Jul 14–Jul 28 |
| Aster | Start seeds indoors Apr 13–Apr 27 Transplant outdoors May 25–Jun 8 |
| Celosia | Start seeds indoors Apr 13–Apr 27 Transplant outdoors Jun 1–Jun 8 |
| Sweet Alyssum | Direct sow outdoors May 11–Jun 8 |
| Morning Glory | Direct sow outdoors May 25–Jun 8 |