When to Plant Kohlrabi in Maryland (2026 Guide)
Kohlrabi is a unique and versatile vegetable that’s making a comeback in many Maryland gardens. With its mild, sweet flavor and crisp texture, it makes a delightful addition to salads and slaws, or can be roasted to bring out its earthy tones. Understanding when to plant kohlrabi in Maryland is essential for a successful harvest, especially considering the area's varying last frost dates.
In Maryland, gardeners should pay close attention to important frost dates, such as the median last spring frost of April 11 in Zone 6b and April 18 in Zone 6a. These dates are crucial for determining the best time to sow seeds and transplant your kohlrabi outdoors. With proper planning, you can take advantage of the ~201-day frost-free season in the warmer zone, allowing ample time for this crop to grow and mature.
Kohlrabi thrives in cool conditions typical of spring and early fall, making it perfect for interplanting with warmer-season crops. With a growth period of just 45 to 60 days from transplant, it's easy to fit kohlrabi into your planting schedule. By taking advantage of Maryland's unique climate and soil conditions, you can enjoy a bountiful harvest of this nutritious brassica.
Planting Schedule by USDA Zone in Maryland
| Zone | Indoor start | Transplant out | Direct sow | Harvest |
|---|---|---|---|---|
| Zone 6b | Start February 15 – March 1, ~6–8 weeks before April 11 | Transplant outdoors April 12 – April 25, after last frost | Direct sow April 12 – May 1, after last frost | Harvest June 1 – June 15, when bulbs are 3 inches in diameter |
| Zone 6a | Start February 22 – March 8, ~6–8 weeks before April 18 | Transplant outdoors April 19 – May 2, after last frost | Direct sow April 19 – May 8, after last frost | Harvest June 11 – June 25, when bulbs are 3 inches in diameter |
| Zone 5b | Start March 22 – April 5, ~6–8 weeks before May 4 | Transplant outdoors May 5 – May 15, after last frost | Direct sow May 5 – May 20, after last frost | Harvest June 20 – July 5, when bulbs are 3 inches in diameter |
Kohlrabi Planting Windows in Maryland
- Indoor start: February 15 – March 8, depending on your specific Maryland zone.
- Transplant outdoors: April 12 – May 2, keeping a close eye on frost dates in your area.
- Harvest: June 1 – July 5, depending on planting dates and bulb size.
Common Mistakes Growing Kohlrabi in Maryland
- Many Maryland gardeners underestimate the impact of late frosts. It's vital to monitor local weather conditions closely to avoid losing young kohlrabi plants. Waiting until after the median last frost is crucial to ensure healthy seedlings and successful transplants.
- Planting kohlrabi too late can result in woody, fibrous bulbs due to the heat in Maryland's late summer. Monitor germination times carefully and aim to harvest before the temperatures rise significantly, especially if you’re in the warmer parts of the state.
- Not providing adequate spacing for kohlrabi can lead to overcrowding, which affects bulb development. Make sure to allow enough room between plants to enable proper growth, helping to maintain the quality of the crop and avoid competition for nutrients.
- Many gardeners forget to protect young kohlrabi from pests such as cabbage worms, particularly during humid Maryland summers. Regularly check for signs of infestation and consider organic methods or barriers for effective pest management to ensure your plants thrive.
- Assuming kohlrabi will thrive in all soil types can be a major mistake. Maryland's clay and alkaline soils may need amending to ensure adequate drainage and nutrient levels. Conducting a soil test can help inform your amendments for optimal growth.
Frequently Asked Questions
What if I'm in a cold pocket of Maryland?
If you're in a colder zone, consider starting kohlrabi seeds indoors earlier or waiting until the soil warms uniquely for your area. You can also cover your plants with row covers to protect against unexpected late frosts.
Can I still plant kohlrabi in May?
Yes, in Zone 6b and even Zone 6a, you can still direct sow kohlrabi in early May, but be cautious about the soil temperature and ensure protection from any late frosts and rising summer heat.
How do I know when to harvest kohlrabi?
Kohlrabi should be harvested when its bulbs reach about 3 inches in diameter for the best flavor and texture. Check frequently to avoid letting them grow too large, as they may become tough and unpalatable.
What should I do if my kohlrabi faces heat stress?
If you notice signs of heat stress, such as bolting or woody texture, consider shading your plants during the hottest part of the day. Keeping them adequately watered will help maintain their health and quality.
Is kohlrabi easy to grow in Maryland?
Yes, kohlrabi is considered one of the easier brassicas to grow in Maryland due to its quick growth and frost tolerance. Just pay attention to planting times and environmental conditions for optimal results.
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Other crops in Maryland
Typical fall sowing window for Kohlrabi in Maryland: August 15 – September 5.