When to Plant Spinach in Maine
Fast from seed to salad. Spinach bolts in heat, so plant early in spring and again in fall.
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 |
Spinach 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 Spinach in Maine
Spinach in Maine's Climate
Your cool climate extends the spinach season significantly compared to warmer zones. Direct sow as soon as soil thaws — spinach germinates in soil as cool as 35°F. Michigan and Minnesota gardeners may get 6-8 weeks of production before bolting versus 3-4 weeks in the South. Fall spinach from an August sowing is equally productive and often superior in quality.
Soil Considerations for Maine
Acidic, rocky soils. Blueberries thrive naturally. Raised beds common to deal with rocks. Amendment with lime needed for many vegetables.
Maine Climate & Growing Season
Short growing season but long summer days help. Maritime influence on coast. Season extension techniques very valuable. Spinach can handle frost well, which is an advantage in Maine's climate. You can push planting dates earlier in spring and extend into fall.
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 spinach — adjust your planting dates to match your specific region.
Growing Tips
Direct sow as soon as soil can be worked in spring. For fall, plant 6-8 weeks before first frost.
Companion Planting
Plant spinach alongside these companions for better growth:
The Bottom Line
Last reviewed: March 29, 2026