When to Plant Kohlrabi in New Jersey (2026 Guide)
Kohlrabi is a unique and delicious vegetable that many gardeners in New Jersey are discovering. Known for its bulbous stem that sits just above soil level, it offers a sweet, mild flavor reminiscent of broccoli stems. This vegetable is not only easy to grow but also thrives in the cool temperatures of early spring and early fall, making it a versatile addition to your garden plots.
In New Jersey, this cool-season crop can be successfully planted a few weeks before the last frost, especially as it tolerates frost quite well. If you're in Zone 6a, expect your last spring frost around April 22. For gardeners operating in Zone 7a, you'll want to have your plants ready by April 1 to ensure the best conditions for growth.
Harvesting kohlrabi is straightforward and rewarding, with bulbs reaching peak flavor at around 3 inches in diameter. Given the impressive frost-free season in New Jersey—around 181 to 228 days depending on your zone—there's ample opportunity to cultivate this nutritious vegetable.
Planting Schedule by USDA Zone in New Jersey
| Zone | Indoor start | Transplant out | Direct sow | Harvest |
|---|---|---|---|---|
| Zone 6a | Start February 15 – March 1, ~6–8 weeks before April 22 | Transplant outdoors April 22 – May 10, after the last frost | Direct sow indoors or outdoors April 22 – May 10 | Harvest from June 7 – July 7, about 45–60 days after transplanting |
| Zone 7a | Start February 1 – February 15, ~6–8 weeks before April 1 | Transplant outdoors April 1 – April 15, after the last frost | Direct sow indoors or outdoors April 1 – April 15 | Harvest from May 15 – June 15, about 45–60 days after transplanting |
| Zone 6b | Start February 25 – March 10, ~6–8 weeks before April 11 | Transplant outdoors April 11 – April 25, after the last frost | Direct sow indoors or outdoors April 11 – April 25 | Harvest from May 25 – June 25, about 45–60 days after transplanting |
Kohlrabi Planting Windows in New Jersey
- Indoor start: For New Jersey, the ideal indoor start window for kohlrabi is from February 1 to March 10, depending on your zone.
- Transplant outdoors: Transplanting kohlrabi outdoors should occur between April 1 and April 25, based on your specific frost-free date.
- Harvest: Kohlrabi in New Jersey is generally ready for harvest between May 15 and June 25, approximately 45–60 days after transplanting.
Common Mistakes Growing Kohlrabi in New Jersey
- One common mistake in New Jersey is planting kohlrabi too late in the spring, especially with the potential for late frosts. Those in Zone 6a should take note of April 22 to avoid losing their crop.
- New Jersey's soil types can vary widely. Gardeners often fail to amend their soil, which can lead to a poor kohlrabi harvest. Testing soil pH is essential, as kohlrabi prefers slightly acidic to neutral soil.
- Overcrowding kohlrabi plants is a frequent error. With New Jersey's humid climate, allowing proper air circulation is vital for preventing diseases like downy mildew, which can severely impact kohlrabi.
- Neglecting the leaves of kohlrabi is a mistake many make. New Jersey gardeners should utilize these nutritious greens similarly to how they would use kale or collard greens due to their flavorful contribution to dishes.
- Many New Jersey gardeners may overlook the importance of rotating crops. Since kohlrabi is a brassica, it's crucial to rotate with other plants to reduce the risk of soil-borne diseases affecting subsequent crops.
Frequently Asked Questions
What if I'm in a cold pocket of New Jersey?
If you're in a colder part of New Jersey, you may want to adjust your planting dates slightly later. Kohlrabi is frost-tolerant, but you still need to ensure it has the right conditions to thrive.
Can I still plant kohlrabi in May?
While you can still plant kohlrabi in May, it's best done in earlier May for optimal growth. Be mindful of the heat as it can stress the plant and affect bulb quality.
How long does it take for kohlrabi to mature?
Kohlrabi typically matures within 45 to 60 days from transplanting, making it a relatively quick crop. Be sure to harvest at the right time for the best taste and texture.
Should I worry about pests when growing kohlrabi?
Yes, kohlrabi can attract pests like aphids and cabbage worms. Regular monitoring is essential, and you can use organic methods such as neem oil or insecticidal soap to control infestations.
What are the common diseases affecting kohlrabi?
Kohlrabi can be susceptible to diseases like downy mildew and black rot. To manage these, ensure good air circulation, avoid overhead watering, and practice crop rotation each season.
Keep Learning
City guides in New Jersey
Other crops in New Jersey
Typical fall sowing window for Kohlrabi in New Jersey: August 14 – September 4.