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Zone 3b Planting Calendar

Zone 3b has an average minimum temperature range of -35°F to -30°F. The average last spring frost is around May 10 and the first fall frost is around September 22, giving you approximately 135 days in the growing season.

There are 124 plants in our database that grow well in Zone 3b.

Zone 3b Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22
Zone 3b Frost Countdown
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Last Frost: May 10 First Frost: Sep 22

States That Include Zone 3b

Many states span multiple zones. The states highlighted below contain areas classified as Zone 3b.

Growing Season Comparison

What to Plant Right Now in Zone 3b

Based on April 2026 planting windows.

See all April plantings →

All Planting Windows at a Glance

This chart shows when to start, transplant, sow, and harvest every plant in Zone 3b.

Vegetables for Zone 3b

Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Acorn Squash Mar 29 May 24 May 31 Aug 23 – Sep 27 80–100
Amaranth Mar 8 May 24 May 31 Aug 30 – Oct 4 90–120
Arugula Mar 29 May 3 May 10 Jun 14 – Aug 16 30–50
Asparagus May 24 730–1095
Beets May 3 Jun 28 – Jul 26 50–70
Belgian Endive Mar 29 May 3 May 10 Aug 30 – Sep 13 110–150
Black Beans May 24 Aug 23 – Sep 27 90–120
Bok Choy Mar 29 May 3 May 10 Jun 21 – Jul 26 40–60
Broccoli Mar 29 May 3 May 10 Jul 12 – Aug 23 60–90
Broccoli Rabe Mar 29 May 3 May 10 Jun 21 – Jul 26 40–60
Brussels Sprouts Mar 29 May 3 May 10 Aug 9 – Sep 13 90–130
Butternut Squash Mar 29 May 24 May 31 Aug 30 – Oct 4 85–110
Cabbage Mar 29 May 3 May 10 Jul 12 – Sep 6 60–100
Carrots May 3 Jul 5 – Aug 9 60–80
Cauliflower Mar 29 May 3 May 10 Jul 5 – Sep 6 55–100
Celeriac Mar 29 May 3 May 10 Aug 23 – Sep 13 100–120
Celery Mar 29 May 3 May 10 Aug 2 – Sep 13 80–120
Celtuce Mar 29 May 3 May 10 Jul 12 – Aug 23 60–90
Chard Mar 29 May 3 May 10 Jul 5 – Aug 23 50–60
Chickpeas Mar 29 May 3 May 10 Aug 2 – Sep 13 80–110
Chicory Mar 29 May 3 May 10 Jul 12 – Aug 23 60–85
Chinese Cabbage Mar 29 May 3 May 10 Jul 5 – Aug 2 50–70
Collard Greens Mar 29 May 3 May 10 Jul 5 – Sep 6 55–75
Corn May 24 Jul 26 – Sep 20 60–100
Cress Mar 29 May 3 May 10 May 24 – Jun 14 14–21
Crookneck Squash Mar 29 May 24 May 31 Jul 19 – Aug 16 45–60
Cucumber Mar 29 May 24 May 31 Jul 26 – Sep 20 50–70
Daikon May 3 Jun 28 – Jul 26 50–70
Delicata Squash Mar 29 May 24 May 31 Aug 23 – Sep 27 80–100
Edamame May 24 Aug 9 – Sep 20 75–100
Endive Mar 29 May 3 May 10 Jun 28 – Aug 2 45–65
Escarole Mar 29 May 3 May 10 Jul 5 – Aug 2 50–70
Fava Beans Mar 29 May 3 May 10 Jul 26 – Sep 6 75–100
Garlic 90–240
Green Beans May 24 Jul 19 – Sep 13 50–65
Horseradish May 24 Sep 27 120–180
Hubbard Squash Mar 29 May 24 May 31 Sep 13 – Oct 4 100–120
Kabocha Mar 29 May 24 May 31 Aug 30 – Sep 27 85–100
Kai Lan Mar 29 May 3 May 10 Jun 28 – Jul 26 45–60
Kale Mar 29 May 3 May 10 Jul 5 – Aug 30 50–70
Kidney Beans May 24 Aug 23 – Sep 27 85–110
Kohlrabi Mar 29 May 3 May 10 Jun 28 – Aug 2 45–65
Komatsuna Mar 29 May 3 May 10 Jun 14 – Jul 19 35–50
Leeks Mar 29 May 3 May 10 Aug 9 – Sep 13 90–150
Lentils Mar 29 May 3 May 10 Aug 2 – Sep 13 80–110
Lettuce Mar 29 May 3 May 10 Jun 14 – Aug 23 30–60
Lima Beans May 24 Jul 26 – Sep 6 60–90
Mache Mar 29 May 3 May 10 Jun 21 – Jul 26 40–60
Microgreens Mar 29 May 3 May 10 May 17 – Jun 14 7–21
Mizuna Mar 29 May 3 May 10 Jun 14 – Jul 12 30–45
Mustard Greens Mar 29 May 3 May 10 Jun 14 – Aug 16 30–50
Napa Cabbage Mar 29 May 3 May 10 Jul 5 – Aug 9 55–75
Onion Mar 29 May 3 May 10 Aug 9 – Sep 13 90–120
Pac Choi Mar 29 May 3 May 10 Jun 21 – Jul 19 40–55
Parsnip May 3 Aug 16 – Sep 6 100–130
Patty Pan Squash Mar 29 May 24 May 31 Jul 19 – Aug 16 45–60
Peas Mar 29 May 3 May 10 Jul 5 – Aug 30 55–70
Peppers Feb 22 May 24 May 31 Aug 2 – Oct 4 60–90
Pole Beans Mar 8 May 24 May 31 Jul 26 – Sep 20 55–70
Potatoes Mar 8 May 24 May 31 Aug 9 – Oct 4 70–120
Pumpkin Mar 29 May 24 May 31 Aug 30 – Oct 4 85–120
Purslane Mar 29 May 3 May 10 Jun 21 – Jul 26 40–60
Radish May 3 May 31 – Jun 21 22–35
Rhubarb Jun 7 365–730
Romanesco Mar 29 May 3 May 10 Jul 26 – Sep 6 75–100
Rutabaga May 3 Jul 26 – Aug 30 80–100
Salsify May 3 Aug 16 – Sep 6 100–130
Savoy Cabbage Mar 29 May 3 May 10 Jul 19 – Sep 13 70–110
Scallions Mar 29 May 3 May 10 Jul 5 – Aug 2 50–70
Scarlet Runner Beans Mar 8 May 24 May 31 Aug 2 – Sep 6 60–80
Shiso Mar 15 May 17 May 31 Jul 26 – Sep 20 50–70
Snap Peas Mar 8 May 24 May 31 Jul 26 – Sep 20 55–70
Snow Peas Mar 29 May 3 May 10 Jul 5 – Aug 30 50–65
Soybeans May 24 Aug 16 – Sep 27 80–120
Spaghetti Squash Mar 29 May 24 May 31 Aug 30 – Sep 27 85–100
Spinach Mar 29 May 3 May 10 Jun 14 – Aug 16 35–50
Squash (Summer) Mar 29 May 24 May 31 Jul 19 – Sep 20 45–65
Squash (Winter) Mar 29 May 24 May 31 Aug 23 – Oct 4 80–120
Sunchoke May 24 Sep 13 – Sep 27 110–150
Sunflower Mar 8 May 24 May 31 Aug 9 – Sep 27 70–100
Sweet Corn May 24 Jul 26 – Sep 6 60–90
Tatsoi Mar 29 May 3 May 10 Jun 14 – Jul 19 35–50
Tomatoes Mar 8 May 24 May 31 Aug 2 – Oct 4 60–85
Turnip May 3 Jun 14 – Jul 19 40–60
Watercress Mar 29 May 3 May 10 Jun 21 – Jul 26 40–60
Wax Beans May 24 Jul 19 – Sep 13 50–65
Zucchini Mar 29 May 24 May 31 Jul 19 – Sep 13 45–60

Fruits for Zone 3b

Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Alpine Strawberries Jun 7 Sep 6 – Oct 11 90–180
Aronia Jun 7 730–1095
Blueberries Jun 7 730–1095
Cranberries Jun 7 730–1095
Currants Jun 7 730–1095
Elderberries Jun 7 730–1095
Goji Berries Jun 7 730–1095
Gooseberries Jun 7 730–1095
Hardy Kiwi Jun 7 1095–1825
Haskaps Jun 7 730–1095
Jostaberry Jun 7 730–1095
Lingonberries Jun 7 730–1095
Raspberries Jun 7 365–730
Serviceberries Jun 7 730–1095
Strawberries Jun 7 Sep 6 – Oct 11 90–365

Herbs for Zone 3b

Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Angelica Mar 29 May 3 May 3 365–730
Bee Balm May 17 Aug 16 – Sep 20 90–120
Borage Mar 29 May 3 May 3 Jun 28 – Aug 16 50–60
Caraway Mar 29 May 3 May 3 365–450
Catnip May 17 Jul 19 – Sep 20 60–80
Chamomile Mar 29 May 3 May 3 Jul 5 – Sep 6 60–90
Chervil Mar 29 May 3 May 3 Jun 14 – Aug 16 40–60
Chives May 17 Jul 19 – Sep 20 60–90
Cilantro Mar 29 May 3 May 3 Jun 14 – Aug 16 40–60
Comfrey May 17 Jul 19 – Sep 20 60–90
Dill Mar 29 May 3 May 3 Jun 14 – Aug 16 40–60
Echinacea May 17 Sep 20 120–180
Garlic Chives May 17 Jul 19 – Sep 20 60–90
Horehound May 17 Aug 2 – Sep 20 75–90
Hyssop May 17 Jul 26 – Sep 20 70–90
Lemon Balm May 17 Jul 19 – Sep 6 60–70
Lovage May 17 Jul 26 – Sep 20 70–90
Mint May 17 Jul 19 – Sep 20 60–90
Parsley Mar 29 May 3 May 3 Jul 5 – Sep 6 60–80
Sorrel Mar 29 May 3 May 3 Jun 14 – Aug 16 40–60
Valerian May 17 Sep 20 120–180
Yarrow May 17 Aug 16 – Sep 20 90–120

Recommended for Your Garden

💡
LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

🔥
Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

🪡
Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

Frequently Asked Questions

What can I grow in Zone 3b?

Zone 3b supports 124 plants in our database including vegetables, herbs, fruits, and flowers. With a 135-day growing season (last frost ~May 10, first frost ~September 22), you can grow most common garden crops with proper timing.

What is Zone 3b?

USDA Zone 3b has an average annual minimum temperature of -35°F to -30°F.

When is the last frost in Zone 3b?

The average last spring frost in Zone 3b is approximately May 10. The first fall frost averages around September 22, giving a growing season of about 135 days. These dates are based on 50% probability — plan for some year-to-year variation.

Level Up Your Garden

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.