When to Plant Marigolds in Minnesota
The ultimate companion plant. Marigolds repel pests, attract pollinators, and add cheerful color all season long.
The Short Answer
Minnesota Frost Dates
Your planting dates depend on which part of Minnesota you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern Minnesota | 3a, 3b | May 15 - Jun 1 | Sep 5 - Sep 20 |
| Central Minnesota | 3b, 4a | May 5 - May 20 | Sep 15 - Oct 1 |
| Southern Minnesota | 4a, 4b | Apr 25 - May 10 | Sep 25 - Oct 10 |
Marigolds Planting Schedule for Minnesota
Northern Minnesota (Zones 3a, 3b)
Average last frost: May 15 - Jun 1 · Average first frost: Sep 5 - Sep 20
Central Minnesota (Zones 3b, 4a)
Average last frost: May 5 - May 20 · Average first frost: Sep 15 - Oct 1
Southern Minnesota (Zones 4a, 4b)
Average last frost: Apr 25 - May 10 · Average first frost: Sep 25 - Oct 10
Growing Marigolds in Minnesota
Marigolds in Minnesota's Climate
Marigolds are surprisingly effective in cold climates despite their frost sensitivity. Start indoors or buy transplants — they grow fast once summer warmth arrives. Plant among vegetables for pest deterrence. French marigolds suppress root-knot nematodes through root chemicals, though nematodes are less common in cold soils.
Soil Considerations for Minnesota
Rich prairie soils in south and west. Rocky and thin soils in north. Generally excellent for gardening in southern half. Make sure soil has warmed to at least 60°F before planting marigolds outside.
Minnesota Climate & Growing Season
Long, cold winters. Warm summers. Short but productive growing season with long summer days. Hardy varieties essential. Marigolds 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 Minnesota: Northern Minnesota (3a, 3b) has a last frost around May 15 - Jun 1, while Southern Minnesota (4a, 4b) sees frost end around Apr 25 - May 10. This difference matters for marigolds — transplant timing shifts by several weeks across the state.
Growing Tips
French marigolds are best for pest control in vegetable gardens. Deadhead spent flowers to keep them blooming until frost.
Companion Planting
Plant marigolds alongside these companions for better growth:
The Bottom Line
Last reviewed: March 29, 2026