When to Plant Kohlrabi in Oregon (2026 Guide)
Kohlrabi is a unique and versatile vegetable that can be an exciting addition to your garden in Oregon. Known for its swollen stem that resembles a bulb, kohlrabi offers a crisp texture and a mild, sweet flavor similar to broccoli. Whether enjoyed raw in salads or cooked, this low-maintenance crop thrives in the cool conditions favored by other brassicas, making it a perfect candidate for both spring and fall planting.
In Oregon, the timing for planting kohlrabi varies depending on your USDA hardiness zone. For instance, if you're in Zone 6b, you can expect the last spring frost around April 11, giving you a clear window for sowing seeds or transplanting seedlings. To achieve optimal growth and flavor, it's essential to understand the specific timings associated with each zone, especially since Oregon experiences diverse climates.
Most importantly, kohlrabi is frost-tolerant, allowing you to extend your growing season significantly. As you plan your garden, be aware that the first fall frost in Zone 6b is typically around October 31. Therefore, understanding your local conditions and frost dates will help you maximize your harvest and enjoy kohlrabi at its best.
Planting Schedule by USDA Zone in Oregon
| 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 – May 1 | Direct sow April 12 – May 1 | Harvest from June 1 – July 15 |
| Zone 6a | Start March 1 – March 15, ~6–8 weeks before April 22 | Transplant outdoors April 23 – May 10 | Direct sow April 23 – May 10 | Harvest from June 15 – August 1 |
| Zone 7a | Start February 15 – March 1, ~6–8 weeks before March 23 | Transplant outdoors March 24 – April 15 | Direct sow March 24 – April 15 | Harvest from May 15 – July 1 |
Kohlrabi Planting Windows in Oregon
- Indoor start: For Oregon gardeners, the indoor start window for kohlrabi is typically from February 15 through March 1.
- Transplant outdoors: You can transplant kohlrabi outdoors in Oregon from April 12 to May 1, depending on your hardiness zone.
- Harvest: The harvest window for kohlrabi in Oregon ranges from June 1 to August 1, optimizing your crop timing.
Common Mistakes Growing Kohlrabi in Oregon
- One common mistake in Oregon is planting kohlrabi too late in the season when summer heat can affect growth. Keep an eye on local weather patterns and be proactive in planting, especially in warmer regions.
- Many new gardeners in Oregon underestimate the importance of soil quality. Kohlrabi thrives in rich, well-draining soil, so proper soil amendments should be considered to ensure a successful crop.
- Another frequent error is neglecting to protect young kohlrabi plants from sudden spring frosts, particularly in the northern parts of Oregon. Use row covers if there’s a risk of colder temperatures.
- Some gardeners mistakenly water kohlrabi too frequently, leading to root rot. It's essential to balance moisture levels, especially in Oregon where heavy rainfall is common in spring.
- There's also a tendency to overlook kohlrabi's maturity timeline. Failing to harvest on time might lead to woody bulbs, lessening the vegetable's desirable texture and flavor.
Frequently Asked Questions
What if I'm in a cold pocket of Oregon?
If you’re in a colder area, consider starting your kohlrabi indoors earlier and transplanting after the last frost. Using row covers can also protect younger plants.
Can I still plant kohlrabi in May?
While it is optimal to plant kohlrabi earlier, you can still direct sow seeds in May in Oregon, especially in warmer areas. Keep in mind that growth might be affected by increasing temperatures.
How long does it take for kohlrabi to mature?
Kohlrabi typically matures in 45 to 60 days after transplanting. Keep an eye on the bulb's size for optimal harvest, ideally when they reach about 3 inches in diameter.
What types of kohlrabi are best in warm weather?
Purple varieties tend to be more heat-tolerant and stay tender when larger than their green counterparts. If you expect high temperatures, opt for purple kohlrabi.
How often should I water kohlrabi?
Water kohlrabi regularly to maintain consistent moisture but avoid overwatering. Ensure the soil drains well, especially in Oregon's spring rains.
Keep Learning
City guides in Oregon
Other crops in Oregon
Typical fall sowing window for Kohlrabi in Oregon: August 21 – September 11.