When to Plant Kohlrabi in Oklahoma (2026 Guide)
Kohlrabi is a unique vegetable that's gaining popularity among Oklahoma gardeners for its sweet, crunchy texture and versatility in the kitchen. This unusual brassica, which develops a swollen stem just above the soil line, thrives in the state's climate, particularly in cooler months. With Oklahoma's median last spring frost occurring as late as April 2 in Zone 6b, kohlrabi can be seamlessly integrated into both spring and fall gardening schedules.
In Oklahoma, kohlrabi is particularly well-suited for planting early in the season, as it takes just 45–60 days from transplant to harvest. The state's varied hardiness zones mean adaptations are necessary for specific locations, whether you're located in metropolitan areas like Oklahoma City and Tulsa or more rural spots. By understanding your zone, you can optimize your planting schedule for maximum yield.
For gardeners in Zone 6b, where winters are longer, you may want to focus on growing kohlrabi early in the season. This is where kohlrabi's frost tolerance becomes advantageous. When planning for kohlrabi, remember the median first fall frost is around October 30 — scheduling your planting to ensure a timely harvest is crucial for enjoying this nutritious vegetable.
Planting Schedule by USDA Zone in Oklahoma
| Zone | Indoor start | Transplant out | Direct sow | Harvest |
|---|---|---|---|---|
| Zone 6b | Start February 15 – March 1, ~6–8 weeks before April 2 | Transplant outdoors from March 15 – April 2, after the last frost | Direct sow from March 15 – April 15, ensuring optimal temperature | Harvest between May 30 – June 15 when bulbs are about 3 inches in diameter |
| Zone 7a | Start February 15 – March 1, ~6–8 weeks before March 30 | Transplant outdoors from March 1 – March 30, after the last spring frost | Direct sow from March 1 – April 15, when soil warms sufficiently | Harvest between May 15 – June 1, targeting ideal bulb size for flavor |
Kohlrabi Planting Windows in Oklahoma
- Indoor start: Start your kohlrabi seeds indoors from February 15 to March 1 to get a head start on the growing season.
- Transplant outdoors: Transplant kohlrabi seedlings outdoors between March 15 and April 2, ensuring they are past the last frost date.
- Harvest: Harvest kohlrabi between May 30 and June 15 to enjoy the best flavor and texture.
Common Mistakes Growing Kohlrabi in Oklahoma
- One common mistake for Oklahoma gardeners is to wait too long to transplant kohlrabi seedlings outdoors. Given the median last spring frost on April 2 in Zone 6b, it's easy to think it's safe to plant later. However, early transplanting will yield better results and avoid potential frost damage.
- Another frequent error is not taking into account Oklahoma's fluctuating temperatures. Sudden temperature drops, even in late spring, can stress plants. Make sure to monitor local weather forecasts and be prepared to protect your seedlings with row covers if needed.
- Planting kohlrabi in the wrong soil type can hinder growth. Oklahoma's clay soil can hold water, thus affecting root development. Preparing the soil by amending it with organic matter can significantly improve drainage and nutrient availability for healthier kohlrabi.
- Some gardeners mistakenly believe that kohlrabi can only be grown in cooler weather. While it thrives in cool conditions, kohlrabi can also endure warmer temperatures. In Oklahoma, choosing purple varieties may offer more heat tolerance for summer planting.
- Lastly, Oklahoma gardeners often undervalue the kohlrabi greens. Many discard them, thinking they're inedible. However, the leaves are nutritious and flavorful, ideal for cooking in various dishes, like stir-fries or soups, so don't waste them!
Frequently Asked Questions
What if I'm in a cold pocket of Oklahoma?
If you're gardening in a colder area of Oklahoma, consider starting your kohlrabi seeds indoors a few weeks earlier or using row covers to protect young plants from unexpected frosts. Monitoring local weather conditions can help.
Can I still plant kohlrabi in May?
While you can plant kohlrabi in May, it's important to acknowledge that the later you plant, the more likely you'll experience higher temperatures, which may affect growth and flavor, particularly for green varieties.
How often should I water kohlrabi?
Kohlrabi prefers consistent moisture, so aim to keep the soil evenly moist, especially during dry spells. Regular watering, approximately 1 inch per week, ensures optimal growth and bulb formation.
Can I use kohlrabi leaves in recipes?
Absolutely! Kohlrabi leaves are not only edible but also nutritious. You can cook them just like kale or collard greens in various dishes like salads, stir-fries, or soups to gain additional flavor and health benefits.
Should I worry about pests when growing kohlrabi?
While kohlrabi is relatively resilient, it's still susceptible to pests like aphids and cabbage worms. Regularly inspect your plants and consider using organic pest controls if you notice any infestations to maintain a healthy crop.
Keep Learning
City guides in Oklahoma
Other crops in Oklahoma
Typical fall sowing window for Kohlrabi in Oklahoma: August 25 – September 15.