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What to Plant in September — USDA Zone 3b

Here's everything you can start, transplant, sow, and harvest in September in USDA Zone 3b. This zone has an average last spring frost around May 10 and first fall frost around September 22, with a growing season of approximately 135 days.

There are 64 planting activities for September in Zone 3b.

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

Where Is Zone 3b?

Harvest in September

Plant Type Date Range Days to Maturity
Acorn Squash Vegetable 80–100 days
Alpine Strawberries Fruit 90–180 days
Amaranth Vegetable 90–120 days
Bee Balm Herb 90–120 days
Belgian Endive Vegetable 110–150 days
Black Beans Vegetable 90–120 days
Brussels Sprouts Vegetable 90–130 days
Butternut Squash Vegetable 85–110 days
Cabbage Vegetable 60–100 days
Catnip Herb 60–80 days
Cauliflower Vegetable 55–100 days
Celeriac Vegetable 100–120 days
Celery Vegetable 80–120 days
Chamomile Herb 60–90 days
Chickpeas Vegetable 80–110 days
Chives Herb 60–90 days
Collard Greens Vegetable 55–75 days
Comfrey Herb 60–90 days
Corn Vegetable 60–100 days
Cucumber Vegetable 50–70 days
Delicata Squash Vegetable 80–100 days
Echinacea Herb 120–180 days
Edamame Vegetable 75–100 days
Fava Beans Vegetable 75–100 days
Garlic Chives Herb 60–90 days
Green Beans Vegetable 50–65 days
Horehound Herb 75–90 days
Horseradish Vegetable 120–180 days
Hubbard Squash Vegetable 100–120 days
Hyssop Herb 70–90 days
Kabocha Vegetable 85–100 days
Kidney Beans Vegetable 85–110 days
Leeks Vegetable 90–150 days
Lemon Balm Herb 60–70 days
Lentils Vegetable 80–110 days
Lima Beans Vegetable 60–90 days
Lovage Herb 70–90 days
Mint Herb 60–90 days
Onion Vegetable 90–120 days
Parsley Herb 60–80 days
Parsnip Vegetable 100–130 days
Peppers Vegetable 60–90 days
Pole Beans Vegetable 55–70 days
Potatoes Vegetable 70–120 days
Pumpkin Vegetable 85–120 days
Romanesco Vegetable 75–100 days
Salsify Vegetable 100–130 days
Savoy Cabbage Vegetable 70–110 days
Scarlet Runner Beans Vegetable 60–80 days
Shiso Vegetable 50–70 days
Snap Peas Vegetable 55–70 days
Soybeans Vegetable 80–120 days
Spaghetti Squash Vegetable 85–100 days
Squash (Summer) Vegetable 45–65 days
Squash (Winter) Vegetable 80–120 days
Strawberries Fruit 90–365 days
Sunchoke Vegetable 110–150 days
Sunflower Vegetable 70–100 days
Sweet Corn Vegetable 60–90 days
Tomatoes Vegetable 60–85 days
Valerian Herb 120–180 days
Wax Beans Vegetable 50–65 days
Yarrow Herb 90–120 days
Zucchini Vegetable 45–60 days

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.