When to Plant Turnip in Idaho (2026 Guide)
Growing turnips in Idaho offers a rewarding gardening experience thanks to their fast growth and cold-hardiness. With a frost-free season that varies from zone to zone, Idaho gardeners can plant turnips at the right time to ensure a bountiful harvest. For those in Boise, for example, the median last spring frost is May 6, providing ample opportunity for successful cultivation.
Turnips are ideally sown directly into the ground, as they are a taproot crop that does not transplant well. The key to a successful crop is to sow when the soil is cool but not cold, ideally planning for a summer and fall harvest. In Nampa, you can expect your last spring frost around May 6 to May 25, which helps you time your planting.
These versatile vegetables can be harvested as both roots and greens, making them an excellent choice for diverse culinary applications. For those in Idaho Falls, be mindful that the growing season is shorter, with a last spring frost around June 12, emphasizing the importance of early sowing in both spring and late summer for optimal results.
Planting Schedule by USDA Zone in Idaho
| Zone | Indoor start | Transplant out | Direct sow | Harvest |
|---|---|---|---|---|
| Zone 5b | Not recommended — direct sow only. | Not recommended — direct sow only. | Start March 15 – April 1, ~6–8 weeks after May 6. | Harvest June 15 – August 1. |
| Zone 5a | Not recommended — direct sow only. | Not recommended — direct sow only. | Start April 15 – May 1, ~6–8 weeks after May 25. | Harvest July 1 – August 15. |
| Zone 4b | Not recommended — direct sow only. | Not recommended — direct sow only. | Start June 1 – June 15, ~6–8 weeks before September 5. | Harvest August 15 – October 1. |
Turnip Planting Windows in Idaho
- Indoor start: Indoor starting for turnips is not recommended; they should be direct sown in the garden.
- Transplant outdoors: Outdoor transplanting for turnips is not recommended; they should be direct sown.
- Harvest: Turnips can be harvested from early summer to early fall, typically June 15 – October 1 depending on the planting date.
Common Mistakes Growing Turnip in Idaho
- One common mistake Idaho gardeners make is assuming that all turnips can be started indoors. Turnips are sensitive to transplanting, so they should always be direct sown to ensure proper root development.
- In Idaho's diverse climates, gardeners often overlook soil temperature. Planting turnips in soil that's too cold can result in poor germination and stunted growth, reducing harvest potential.
- Another mistake is planting turnips too late in Zone 4b. With a median last frost of June 12, there is limited time to grow a successful crop before fall frosts arrive.
- Some Idaho gardeners plant turnips too densely. It's vital to thin them after germination to avoid competition for nutrients, which leads to small, elongated roots instead of full-sized turnips.
- Idaho's humidity fluctuations can affect turnip growth. It’s important to ensure consistent moisture levels, particularly in early stages, to help seeds germinate and grow strong.
Frequently Asked Questions
What if I'm in a cold pocket of Idaho?
If you're in a colder area, consider starting your turnips a bit later but ensure to still plant them after the last frost date. Monitor soil conditions closely to ensure they are warm enough for germination.
Can I still plant turnip in May?
Yes, if you're in a warmer region like Boise, you can plant turnips in early May, but ensure to keep an eye on overnight temperatures to protect them from any late frosts.
Are turnip greens edible?
Absolutely! The greens are nutritious and can be harvested starting about 4–6 weeks after sowing. Use them in salads or cooked dishes where they provide a delicious mustard-like flavor.
When should I expect to harvest my turnips?
Depending on when you sow them, expect to harvest your turnips anywhere from June 15 to October 1. Harvesting at the right time ensures the best flavor and texture.
How should I store my turnips after harvest?
Turnips can be stored in a cool, dark place. They can also be left in the ground and covered with straw to protect them through the winter, which improves their sweetness.
Keep Learning
City guides in Idaho
Other crops in Idaho
Typical fall sowing window for Turnip in Idaho: August 3 – August 24.