State growing guide
Maine Planting Guide
USDA Zone 4b/5a · Last frost May 15 · First frost Sep 22 · 130 days
Zone-specific planting calendar, major city frost dates, top crops, and Duke's tips for growing food in Maine.
Frost Dates by City — Maine
Average frost dates for major Maine cities. Use these to calculate your indoor start dates and transplant windows.
| City | USDA Zone | Last Spring Frost | First Fall Frost | Tomato Transplant Window |
|---|---|---|---|---|
| Portland | 5a | May 10 | Sep 25 | ~2 wks after (May 10) |
| Augusta | 5a | May 10 | Sep 25 | ~2 wks after (May 10) |
| Bangor | 4b | May 20 | Sep 20 | ~2 wks after (May 20) |
| Bar Harbor | 5b | May 5 | Oct 5 | ~2 wks after (May 5) |
Average dates based on 30-year NOAA climate normals. Individual years may vary ±2 weeks. Use the Zone Lookup Tool for ZIP-specific dates.
Duke's Top Tips for Maine Gardeners
- Maine's short season demands short-season varieties (under 75 days)
- Start ALL warm-season crops indoors — no direct sowing of tomatoes or peppers
- Row covers extend the season by 2–4 weeks on both ends
- Maine soil tends to be acidic — lime every fall for vegetables
Common Challenges in Maine
- ⚠ Very short growing season (100–140 days depending on location)
- ⚠ Late June frosts possible in northern Maine
- ⚠ Potato blight is a historic problem — choose resistant varieties
Best Crops for Maine
Get exact dates for your ZIP code in Maine
City averages are a starting point. Your actual microclimate matters — enter your ZIP for precise frost dates.
Frequently Asked Questions — Maine Gardening
What zone is Maine?
Maine ranges from Zone 3b (far north) to Zone 6a (coastal York County). Portland is Zone 5a–5b, Bangor is Zone 4b, and the far north is Zone 3b.
When to plant tomatoes in Maine?
Start seeds indoors in early to mid-April. Transplant outside after June 1 in most of Maine (May 20 in coastal areas). Choose Early Girl, Juliet, or Stupice for reliable harvests in Maine.