Zone 1b planting calendar
Subarctic; a very brief summer. Season extenders (cold frames, row cover) are essential.
Coldest temps-55 to -50°F
Avg. last spring frostJun 10
Avg. first fall frostAug 20
Open the interactive calendar for Zone 1b →
The growing season in Zone 1b
Zone 1b has a coldest-winter range of -55 to -50°F and an average frost-free growing season of roughly 71 days — from the last spring frost around Jun 10 to the first fall frost around Aug 20. 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 Jun 10, and the longer-season ones among them (melons, winter squash, full-size tomatoes) are the plants to watch against the 71-day window. Start those indoors on the schedule below so they have time to finish before fall frost returns.
What to plant in Zone 1b
Every crop below is timed to Zone 1b'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 22–May 6 Transplant outdoors Jun 17–Jun 24 |
| Pepper | Start seeds indoors Apr 8–Apr 22 Transplant outdoors Jun 24–Jul 1 |
| Lettuce | Direct sow outdoors May 13–Jun 10 Direct sow outdoors Jun 25–Jul 9 |
| Carrot | Direct sow outdoors May 20–Jun 24 Direct sow outdoors Jun 11–Jun 25 |
| Bush Bean | Direct sow outdoors Jun 10–Jul 8 |
| Cucumber | Start seeds indoors May 20–May 27 Transplant outdoors Jun 17–Jun 24 Direct sow outdoors Jun 17–Jul 1 |
| Zucchini | Direct sow outdoors Jun 10–Jul 1 |
| Spinach | Direct sow outdoors Apr 29–May 27 Direct sow outdoors Jun 25–Jul 16 |
| Kale | Start seeds indoors Apr 29–May 13 Transplant outdoors May 27–Jun 10 Direct sow outdoors May 27–Jun 24 Direct sow outdoors May 28–Jun 25 |
| Pea | Direct sow outdoors Apr 29–May 20 |
| Basil | Start seeds indoors Apr 29–May 13 Transplant outdoors Jun 17–Jul 1 |
| Cilantro | Direct sow outdoors May 20–Jun 17 Direct sow outdoors Jun 25–Jul 16 |
| Broccoli | Start seeds indoors Apr 22–May 6 Transplant outdoors May 27–Jun 10 Direct sow outdoors May 14–Jun 4 |
| Cabbage | Start seeds indoors Apr 15–Apr 29 Transplant outdoors May 27–Jun 10 |
| Cauliflower | Start seeds indoors Apr 22–May 6 Transplant outdoors May 27–Jun 10 |
| Brussels Sprouts | Start seeds indoors Apr 29–May 13 Transplant outdoors Jun 3–Jun 17 |
| Onion | Start seeds indoors Apr 1–Apr 15 Transplant outdoors May 13–May 27 |
| Garlic | Direct sow outdoors Jul 23–Aug 6 |
| Beet | Direct sow outdoors May 13–Jun 10 Direct sow outdoors Jun 11–Jun 25 |
| Radish | Direct sow outdoors May 13–Jun 24 Direct sow outdoors Jun 25–Jul 23 |
| Swiss Chard | Direct sow outdoors May 27–Jun 24 |
| Potato | Direct sow outdoors May 27–Jun 24 |
| Sweet Corn | Direct sow outdoors Jun 10–Jul 1 |
| Eggplant | Start seeds indoors Apr 15–Apr 29 Transplant outdoors Jun 24–Jul 1 |
| Pumpkin | Direct sow outdoors Jun 10–Jul 1 |
| Winter Squash | Direct sow outdoors Jun 10–Jul 1 |
| Arugula | Direct sow outdoors May 13–Jun 10 Direct sow outdoors Jun 25–Jul 23 |
| Leek | Start seeds indoors Apr 1–Apr 15 Transplant outdoors May 13–May 27 |
| Turnip | Direct sow outdoors May 13–Jun 10 Direct sow outdoors Jun 25–Jul 9 |
| Kohlrabi | Direct sow outdoors May 13–Jun 10 Direct sow outdoors Jun 25–Jul 9 |
| Okra | Start seeds indoors May 13–May 27 Direct sow outdoors Jun 17–Jul 1 |
| Celery | Start seeds indoors Apr 1–Apr 15 Transplant outdoors Jun 3–Jun 17 |
| Collard Greens | Start seeds indoors Apr 29–May 13 Transplant outdoors May 27–Jun 10 Direct sow outdoors May 28–Jun 25 |
| Mustard Greens | Direct sow outdoors May 13–Jun 10 Direct sow outdoors Jun 25–Jul 16 |
| Bok Choy | Direct sow outdoors May 20–Jun 10 Direct sow outdoors Jun 25–Jul 16 |
| Fennel | Direct sow outdoors May 27–Jun 24 Direct sow outdoors Jun 11–Jun 25 |
| Sweet Potato | Transplant outdoors Jun 24–Jul 8 |
| Parsnip | Direct sow outdoors May 27–Jun 24 |
| Asparagus | Transplant outdoors May 13–May 27 |
| Parsley | Start seeds indoors Apr 15–Apr 29 Transplant outdoors May 27–Jun 10 Direct sow outdoors May 27–Jun 24 |
| Dill | Direct sow outdoors May 27–Jun 24 Direct sow outdoors Jun 25–Jul 9 |
| Chives | Start seeds indoors Apr 15–Apr 29 Transplant outdoors May 27–Jun 10 |
| Thyme | Start seeds indoors Apr 15–Apr 29 Transplant outdoors Jun 10–Jun 24 |
| Oregano | Start seeds indoors Apr 15–Apr 29 Transplant outdoors Jun 10–Jun 24 |
| Sage | Start seeds indoors Apr 15–Apr 29 Transplant outdoors Jun 10–Jun 24 |
| Rosemary | Start seeds indoors Apr 1–Apr 15 Transplant outdoors Jun 24–Jul 8 |
| Mint | Transplant outdoors Jun 10–Jun 24 |
| Lavender | Start seeds indoors Apr 1–Apr 15 Transplant outdoors Jun 10–Jun 24 |
| Chamomile | Direct sow outdoors May 27–Jun 24 |
| Lemon Balm | Start seeds indoors Apr 15–Apr 29 Transplant outdoors Jun 10–Jun 24 |
| Tarragon | Transplant outdoors Jun 10–Jun 24 |
| Strawberry | Transplant outdoors May 13–May 27 |
| Watermelon | Start seeds indoors May 13–May 27 Transplant outdoors Jun 24–Jul 1 Direct sow outdoors Jun 17–Jul 1 |
| Cantaloupe | Start seeds indoors May 13–May 27 Transplant outdoors Jun 24–Jul 1 Direct sow outdoors Jun 17–Jul 1 |
| Ground Cherry | Start seeds indoors Apr 22–May 6 Transplant outdoors Jun 17–Jun 24 |
| Blueberry | Transplant outdoors May 13–May 27 |
| Raspberry | Transplant outdoors May 6–May 20 |
| Blackberry | Transplant outdoors May 6–May 20 |
| Rhubarb | Transplant outdoors May 6–May 20 |
| Currant | Transplant outdoors Apr 29–May 20 |
| Gooseberry | Transplant outdoors Apr 29–May 20 |
| Marigold | Start seeds indoors Apr 29–May 13 Transplant outdoors Jun 17–Jun 24 Direct sow outdoors Jun 10–Jun 24 |
| Zinnia | Start seeds indoors May 13–May 27 Transplant outdoors Jun 17–Jun 24 Direct sow outdoors Jun 10–Jun 24 |
| Sunflower | Direct sow outdoors Jun 10–Jul 1 |
| Cosmos | Direct sow outdoors Jun 10–Jun 24 |
| Nasturtium | Direct sow outdoors Jun 10–Jun 24 |
| Sweet Pea | Direct sow outdoors Apr 29–May 20 |
| Snapdragon | Start seeds indoors Apr 15–Apr 29 Transplant outdoors May 27–Jun 10 |
| Pansy | Start seeds indoors Apr 1–Apr 15 Transplant outdoors May 13–May 27 |
| Dahlia | Start seeds indoors May 13–May 27 Transplant outdoors Jun 17–Jun 24 |
| Calendula | Direct sow outdoors May 27–Jun 24 Direct sow outdoors Jun 25–Jul 9 |
| Poppy | Direct sow outdoors Apr 29–May 27 |
| Cornflower | Direct sow outdoors May 13–Jun 3 Direct sow outdoors Jun 25–Jul 9 |
| Aster | Start seeds indoors Apr 29–May 13 Transplant outdoors Jun 10–Jun 24 |
| Celosia | Start seeds indoors Apr 29–May 13 Transplant outdoors Jun 17–Jun 24 |
| Sweet Alyssum | Direct sow outdoors May 27–Jun 24 |
| Morning Glory | Direct sow outdoors Jun 10–Jun 24 |