When to Plant Squash (Summer) in New Hampshire
Zucchini and yellow squash are the garden's most generous producers. You'll be sharing with neighbors by midsummer.
The Short Answer
New Hampshire Frost Dates
Your planting dates depend on which part of New Hampshire you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern New Hampshire | 3b, 4a, 4b | May 20 - Jun 5 | Sep 10 - Sep 25 |
| Southern New Hampshire | 5a, 5b, 6a | May 1 - May 20 | Sep 25 - Oct 10 |
Squash (Summer) Planting Schedule for New Hampshire
Northern New Hampshire (Zones 3b, 4a, 4b)
Average last frost: May 20 - Jun 5 · Average first frost: Sep 10 - Sep 25
Southern New Hampshire (Zones 5a, 5b, 6a)
Average last frost: May 1 - May 20 · Average first frost: Sep 25 - Oct 10
Growing Squash (Summer) in New Hampshire
Squash (Summer) in New Hampshire'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 New Hampshire
Rocky, acidic New England soils. Glacial deposits. Granite bedrock. Raised beds essential in many areas. Make sure soil has warmed to at least 60°F before planting squash (summer) outside.
New Hampshire Climate & Growing Season
Short growing season especially in north. Cold winters. Cool summers. Hardy varieties important. 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 New Hampshire: Northern New Hampshire (3b, 4a, 4b) has a last frost around May 20 - Jun 5, while Southern New Hampshire (5a, 5b, 6a) sees frost end around May 1 - May 20. 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