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What to Plant in September — USDA Zone 5b

Here's everything you can start, transplant, sow, and harvest in September in USDA Zone 5b. This zone has an average last spring frost around April 18 and first fall frost around October 13, with a growing season of approximately 178 days.

There are 51 planting activities for September in Zone 5b.

Zone 5b Moderate season
178 days
Last Spring Frost April 18
178 growing days
First Fall Frost October 13

Where Is Zone 5b?

Harvest in September

Plant Type Date Range Days to Maturity
Alpine Strawberries Fruit 90–180 days
Amaranth Vegetable 90–120 days
Anise Herb 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
Calabash Vegetable 80–120 days
Celeriac Vegetable 100–120 days
Celery Vegetable 80–120 days
Chives Herb 60–90 days
Comfrey Herb 60–90 days
Crosne Vegetable 150–200 days
Cumin Herb 100–120 days
Echinacea Herb 120–180 days
Eggplant Vegetable 65–85 days
Feverfew Herb 90–120 days
Garlic Chives Herb 60–90 days
Ground Cherry Fruit 65–80 days
Honeydew Fruit 80–110 days
Horehound Herb 75–90 days
Horseradish Vegetable 120–180 days
Hot Peppers Vegetable 70–120 days
Hubbard Squash Vegetable 100–120 days
Hyssop Herb 70–90 days
Lavender Herb 90–200 days
Leeks Vegetable 90–150 days
Lemon Thyme Herb 70–90 days
Lovage Herb 70–90 days
Mint Herb 60–90 days
Onion Vegetable 90–120 days
Oregano Herb 60–90 days
Peppers Vegetable 60–90 days
Potatoes Vegetable 70–120 days
Pumpkin Vegetable 85–120 days
Rue Herb 70–90 days
Sage Herb 75–90 days
Shallot Vegetable 90–120 days
Soybeans Vegetable 80–120 days
Squash (Winter) Vegetable 80–120 days
Strawberries Fruit 90–365 days
Sunchoke Vegetable 110–150 days
Sweet Potatoes Vegetable 90–120 days
Tarragon Herb 60–90 days
Thyme Herb 70–90 days
Tomatillo Vegetable 60–85 days
Tomatoes Vegetable 60–85 days
Valerian Herb 120–180 days
Winter Melon Vegetable 90–120 days
Yarrow Herb 90–120 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.