When to Plant Squash (Summer) in Maine
Zucchini and yellow squash are the garden's most generous producers. You'll be sharing with neighbors by midsummer.
The Short Answer
Maine Frost Dates
Your planting dates depend on which part of Maine you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern Maine | 3b, 4a, 4b | May 20 - Jun 5 | Sep 10 - Sep 25 |
| Central Maine | 4b, 5a | May 10 - May 25 | Sep 20 - Oct 5 |
| Southern/Coastal Maine | 5a, 5b, 6a | May 1 - May 15 | Sep 25 - Oct 15 |
Squash (Summer) Planting Schedule for Maine
Northern Maine (Zones 3b, 4a, 4b)
Average last frost: May 20 - Jun 5 · Average first frost: Sep 10 - Sep 25
Central Maine (Zones 4b, 5a)
Average last frost: May 10 - May 25 · Average first frost: Sep 20 - Oct 5
Southern/Coastal Maine (Zones 5a, 5b, 6a)
Average last frost: May 1 - May 15 · Average first frost: Sep 25 - Oct 15
Growing Squash (Summer) in Maine
Squash (Summer) in Maine's Climate
Summer squash (zucchini, yellow squash) is one of the most productive crops for short-season gardens — 45-60 day maturity means even 100-day seasons produce abundant harvests. Direct sow after soil reaches 60°F. Two or three plants produce more squash than most families can eat. Squash vine borer is less prevalent in cold zones, reducing the most frustrating squash pest.
Soil Considerations for Maine
Acidic, rocky soils. Blueberries thrive naturally. Raised beds common to deal with rocks. Amendment with lime needed for many vegetables. Make sure soil has warmed to at least 60°F before planting squash (summer) outside.
Maine Climate & Growing Season
Short growing season but long summer days help. Maritime influence on coast. Season extension techniques very valuable. Squash (Summer) cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
Growing season length varies across Maine: Northern Maine (3b, 4a, 4b) has a last frost around May 20 - Jun 5, while Southern/Coastal Maine (5a, 5b, 6a) sees frost end around May 1 - May 15. This difference matters for squash (summer) — transplant timing shifts by several weeks across the state.
Growing Tips
Harvest when fruits are 6-8 inches long for best flavor. Larger squash become seedy and tough.
Companion Planting
Plant squash (summer) alongside these companions for better growth:
Keep squash (summer) away from:
The Bottom Line
Last reviewed: March 29, 2026