When to Plant Kohlrabi in North Dakota (2026 Guide)

Kohlrabi is a versatile and nutritious vegetable that thrives in North Dakota's unique climate. Given the median last spring frost date of May 12 for Zone 5b, gardeners in cities like Fargo, Bismarck, and Grand Forks can effectively schedule their planting to take advantage of the growing season. This guide will help you understand when to plant kohlrabi so you can enjoy fresh, homegrown produce.

In North Dakota, kohlrabi can be planted both in spring and fall due to its hardiness and quick growth, with optimal growing conditions available from the end of May leading into September. With a frost-free season of approximately 134 days in regions like Fargo, you have ample time to cultivate this tasty brassica. By following the correct planting and harvesting timelines, you can enjoy kohlrabi in various culinary delights.

Planting kohlrabi is straightforward and rewarding, especially for gardeners seeking to fill space early in the season or before fall crops. With a harvest window beginning in early July and running through September 23's first fall frost in Zone 5b, you can enjoy fresh kohlrabi bulbs, crisp and bursting with flavor. Prepare to learn the best practices for this unique crop!

Planting Schedule by USDA Zone in North Dakota

Zone	Indoor start	Transplant out	Direct sow	Harvest
Zone 5b	Start March 15 – March 30, ~6–8 weeks before May 12	Transplant outdoors May 12 – May 30, after the last frost	Direct sow May 12 – June 1, after the last frost	Harvest from July 1 – September 23, before the first fall frost
Zone 5a	Start March 20 – April 5, ~6–8 weeks before May 16	Transplant outdoors May 16 – June 1, after the last frost	Direct sow May 16 – June 1, after the last frost	Harvest from July 5 – September 19, before the first fall frost

Kohlrabi Planting Windows in North Dakota

Indoor start: Start seeds indoors from March 15 to April 5, depending on your specific zone.
Transplant outdoors: Transplant seedlings outdoors between May 12 and June 1 when the frost risk has passed.
Harvest: You can begin harvesting your kohlrabi from July 1 to September 19, ensuring they are picked before the first fall frost.

Common Mistakes Growing Kohlrabi in North Dakota

One common mistake in North Dakota is planting kohlrabi too late. With the last frost in mid-May, waiting until June is risky and can lead to a reduced harvest.
Another issue is not providing adequate water during the warming months. North Dakota can experience dry spells, so maintaining moisture is essential for the bulb's development.
Additionally, some gardeners in North Dakota overlook the effects of late spring frost on tender seedlings. Transplant at the right time to avoid stunted growth or complete crop loss.
Planting kohlrabi too close to heat-sensitive crops can also be problematic. Its quick growth rate can cause overcrowding if not properly managed alongside other brassicas.
Lastly, many mistakenly believe that the kohlrabi bulb is the only edible part. Remember, the leaves are nutritious and should not be discarded. Educate yourself on using them effectively in your recipes.

Frequently Asked Questions

What if I'm in a cold pocket of North Dakota?

If you're in a colder area, you may need to start your kohlrabi seeds indoors earlier or choose cold-tolerant varieties. Pay close attention to local frost dates to ensure successful growth.

Can I still plant kohlrabi in May?

Yes, you can plant kohlrabi in May, especially if you’re in Zone 5b. Just ensure you're planting after the last frost date of May 12 for optimal success in growth.

How do I know when to harvest my kohlrabi?

Harvest kohlrabi when the bulbs are about 3 inches in diameter for the best taste and texture. Typically, this will be around July through early September just before the first frost.

Is kohlrabi a good choice for interplanting?

Absolutely! Kohlrabi is an excellent interplanting option with slower-growing crops. It will be ready to harvest before your summer crops need the space, maximizing garden productivity.

Are the leaves of kohlrabi edible?

Yes, the leaves of kohlrabi are edible and nutritious, similar to kale. They can be cooked or added raw to salads for an extra crunch and nutrient boost.