When to Plant Turnips in Montana
A fast-growing, cold-hardy root crop that's underappreciated. Both the root and the greens are delicious.
The Short Answer
Montana Frost Dates
Your planting dates depend on which part of Montana you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Western Montana | 4b, 5a, 5b | May 10 - May 30 | Sep 10 - Sep 30 |
| Central Montana | 3b, 4a, 4b | May 15 - Jun 5 | Sep 5 - Sep 20 |
| Eastern Montana | 3a, 3b, 4a | May 10 - Jun 1 | Sep 10 - Sep 25 |
Turnips Planting Schedule for Montana
Western Montana (Zones 4b, 5a, 5b)
Average last frost: May 10 - May 30 · Average first frost: Sep 10 - Sep 30
Central Montana (Zones 3b, 4a, 4b)
Average last frost: May 15 - Jun 5 · Average first frost: Sep 5 - Sep 20
Eastern Montana (Zones 3a, 3b, 4a)
Average last frost: May 10 - Jun 1 · Average first frost: Sep 10 - Sep 25
Growing Turnips in Montana
Turnips in Montana's Climate
Turnips are a fast, cold-hardy root crop perfect for extending your short season. Direct sow 3 weeks before last frost and again in late August for frost-sweetened fall harvest. Both roots and greens are edible, doubling the crop's value. Hakurei Japanese salad turnips are especially quick — ready in 30-35 days.
Soil Considerations for Montana
Alkaline soils common. Thin, dry soils in east. Better soils in valleys. Wind erosion challenges. Loose, well-drained soil is especially important for turnips since the edible portion grows underground. If your soil is heavy clay, consider raised beds.
Montana Climate & Growing Season
Short, intense growing season. Low humidity. Wide day-night temperature swings. Wind protection valuable. Turnips can handle frost well, which is an advantage in Montana's climate. You can push planting dates earlier in spring and extend into fall.
Growing season length varies across Montana: Western Montana (4b, 5a, 5b) has a last frost around May 10 - May 30, while Eastern Montana (3a, 3b, 4a) sees frost end around May 10 - Jun 1. This difference matters for turnips — but turnips handle frost well, so the timing difference is less critical.
Growing Tips
Great for spring and fall planting. Harvest small for tender roots. Fall-planted turnips taste sweeter after a frost.
Companion Planting
Plant turnips alongside these companions for better growth:
The Bottom Line
Last reviewed: March 29, 2026