What to Plant in September — Zone 4
Cold winters with a moderate growing season. Many popular vegetables thrive with proper timing.
Quick Answer
In zone 4 during September, early fall — cool-season crops return and the last warm-season crops are harvested. Your key tasks this month: harvest tomatoes, peppers, and winter squash, plant garlic cloves 4-6 weeks before hard freeze, and cover tender crops with row cover on frosty nights.
September Gardening Tasks for Zone 4
September is early fall — cool-season crops return and the last warm-season crops are harvested. Zone 4 has a frost-free window from May 20 – Sept 15, which shapes what you can plant and when. Here is your complete task list:
Plant Guides for This Month
These plants are mentioned in your September tasks. Read their full growing guides for detailed planting instructions:
Tomato
America's most popular garden vegetable, tomatoes come in thousands of varieties…
Garlic
Garlic is the gardener's most patient reward. Planted in autumn and harvested th…
Helpful Guides for September
These gardening guides are especially useful this time of year:
- Seed Starting Indoors — essential if you're starting transplants this month
- Companion Planting Guide — plan your layout for maximum yield
- Organic Pest Control — prepare defenses as the season progresses
- Building Better Soil — start any month to improve next season's harvests
- Pest & Disease Library — identify and solve common garden problems organically
- Browse All Plant Guides — detailed growing instructions for every crop
Frequently Asked Questions
What should I plant in September in zone 4?
In zone 4 during September, focus on: Harvest tomatoes, peppers, and winter squash. Plant garlic cloves 4-6 weeks before hard freeze. Cover tender crops with row cover on frosty nights. The frost-free period for zone 4 is May 20 – Sept 15.
Is it too late to plant in September in zone 4?
September is a productive month in zone 4. Cold winters with a moderate growing season. Many popular vegetables thrive with proper timing. Check each crop's days to maturity against your remaining frost-free window (May 20 – Sept 15).
What is USDA zone 4?
USDA Zone 4 has a frost-free growing season from approximately May 20 – Sept 15. Cold winters with a moderate growing season. Many popular vegetables thrive with proper timing.