When to Plant Kohlrabi in Missouri (2026 Guide)
Kohlrabi is a unique brassica vegetable that offers a tasty and versatile addition to your garden. Known for its distinctive, swollen stem above the soil, kohlrabi embodies a crisp texture with a flavor reminiscent of a milder, sweeter broccoli stem. In Missouri, you can enjoy this nutritious vegetable by timing your planting right, especially in consideration of the key frost dates such as the last spring frost on April 10 in Zone 6b.
Understanding the specific growing conditions in your region is crucial for successfully cultivating kohlrabi. Missouri's climate varies significantly across different areas, with hardiness zones ranging from 6a to 6b. With the first fall frost arriving around October 22 in Zone 6b, gardeners can take advantage of Missouri's approximately 195-day frost-free growing season for optimum kohlrabi production.
Kohlrabi is generally low-maintenance and can be started indoors or directly sown in your garden. With a rapid growth cycle of just 45 to 60 days from transplant, it’s an excellent option for spring and fall planting. Whether you're in Kansas City, St. Louis, or Springfield, properly timing your sowing will ensure a robust harvest of this unusual but delicious vegetable.
Planting Schedule by USDA Zone in Missouri
| Zone | Indoor start | Transplant out | Direct sow | Harvest |
|---|---|---|---|---|
| Zone 6b | Start February 15 – March 1, ~6–8 weeks before April 10 | Transplant outdoors April 15 – April 30, after last frost | Direct sow April 20 – May 10, after soil has warmed | Harvest by June 15 – June 30, when bulbs reach 3 inches |
| Zone 6a | Start March 1 – March 15, ~6–8 weeks before April 19 | Transplant outdoors April 25 – May 5, after last frost | Direct sow May 1 – May 15, when soil warms | Harvest by July 1 – July 15, when bulbs reach 3 inches |
Kohlrabi Planting Windows in Missouri
- Indoor start: For Missouri gardens, start kohlrabi seeds indoors around February 15 – March 1.
- Transplant outdoors: Transplant kohlrabi outdoors from April 15 – April 30 in Missouri after the last frost date.
- Harvest: You can expect to harvest kohlrabi by June 15 – June 30 for the best flavor and texture.
Common Mistakes Growing Kohlrabi in Missouri
- Many Missouri gardeners underestimate the importance of the last frost date. Planting kohlrabi too early can lead to damage from unexpected late spring frosts, particularly in areas with microclimates.
- A frequent mistake is direct sowing kohlrabi too late into the summer. Given Missouri's humid summer, it's essential to plant by mid-May to avoid heat stress that could compromise bulb development.
- Some gardeners fail to consider the spacing required for kohlrabi. Overcrowding can lead to smaller and less flavorful bulbs, which is a common issue that many face in Missouri's rich soil.
- Ignoring the need for crop rotation can result in kohlrabi struggling with pests and diseases. It's essential to rotate with other crops every few years to keep the plants healthy and productive in Missouri's challenging climate.
- Not harvesting kohlrabi at the right time is another mistake. Waiting too long can lead to woody textures, a problem faced by many Missouri gardeners who either lack awareness or forget to check on their crops.
Frequently Asked Questions
What if I'm in a cold pocket of Missouri?
If you're in a colder region, consider starting your kohlrabi seeds indoors to extend your growing season. You can transplant them outdoors after the last frost date, ensuring they have a head start in your garden.
Can I still plant kohlrabi in May?
Yes, you can still plant kohlrabi in May if you direct sow it. Just ensure you’re doing so by May 10 to allow sufficient growth before summer heats up.
How often should I check my kohlrabi for harvesting?
It's best to check your kohlrabi plants every few days as they near maturity. Harvest at about 3 inches in diameter for the best taste and texture, ideally by late June.
What nutrients does kohlrabi need in Missouri's soil?
Kohlrabi thrives in well-drained soil rich in organic matter. Adding compost can provide necessary nutrients to support healthy growth, particularly as Missouri soil can vary in fertility.
Is kohlrabi frost-tolerant?
Yes, kohlrabi is frost-tolerant and can survive light frosts. This makes it an ideal crop for both spring and fall planting in Missouri's climate, ensuring good harvests even with some frost exposure.
Keep Learning
City guides in Missouri
Other crops in Missouri
Typical fall sowing window for Kohlrabi in Missouri: August 11 – September 1.