When to Plant Bok Choy in Washington (2026 Guide)
If you're excited about growing bok choy in Washington, you'll be pleased to know it's a fantastic cool-season crop that thrives in our climate. With its crisp white stalks and tender dark green leaves, bok choy is a versatile ingredient suitable for stir-fries, soups, and salads. Understanding your local frost dates is key: for instance, in Zone 6b, the last spring frost typically occurs around April 9, allowing ample time for a successful crop.
Washington's varied climate zones impact the best planting strategies for bok choy. In Zone 6b, you have about 200 frost-free days, while Zone 6a provides around 182 days. On the other hand, gardeners in Zone 5b have a shorter growing season with about 150 days due to a later last spring frost on May 6. This means timing your planting is crucial to avoid the pitfalls that can arise from late frosts or heat spikes.
As temperatures warm up in late spring, bok choy plants are at risk of bolting if sown too late. Ideally, you'll want to target planting in early spring for the best quality and flavor from your harvest. Planting in the fall can also yield a good harvest due to decreasing temperatures and shorter days, but you'll need to be mindful of the first fall frost date, which is October 26 for many cities in Washington.
Planting Schedule by USDA Zone in Washington
| Zone | Indoor start | Transplant out | Direct sow | Harvest |
|---|---|---|---|---|
| Zone 6b | Start March 1 – March 15, ~6–8 weeks before April 9 | Transplant outdoors April 10 – April 20 | Direct sow outdoors April 10 – April 25 | Harvest by June 1 – June 15 |
| Zone 6a | Start February 15 – March 1, ~6–8 weeks before April 20 | Transplant outdoors April 21 – May 1 | Direct sow outdoors April 21 – May 5 | Harvest by June 15 – June 30 |
| Zone 5b | Start March 15 – March 25, ~6–8 weeks before May 6 | Transplant outdoors May 7 – May 15 | Direct sow outdoors May 7 – May 20 | Harvest by June 30 – July 10 |
Bok Choy Planting Windows in Washington
- Indoor start: For Washington gardeners, the best time to start bok choy indoors is between March 1 and March 25, depending on your specific zone.
- Transplant outdoors: Transplanting outdoors in Washington should occur between April 10 and May 15, varying based on your growing zone.
- Harvest: You can expect to harvest your bok choy between June 1 and July 10, making timely transplanting and sowing essential.
Common Mistakes Growing Bok Choy in Washington
- One common mistake Washington gardeners make is planting bok choy too late. With frost dates varying by region, those in Zone 5b must be mindful of the May 6 last frost to ensure a successful crop. If planted after this date, particularly larger varieties may not mature in time before the summer heat.
- In high-humidity coastal areas of Washington, many novice gardeners neglect the importance of proper air circulation. Bok choy, like many brassicas, can be susceptible to downy mildew. Ensure adequate spacing between plants and consider using a fan to improve airflow, particularly in humid conditions.
- Another frequent oversight is failing to rotate crops properly between growing seasons. Washington’s wet spring conditions can encourage soil-borne diseases, especially in brassicas like bok choy. Ensure a three-year rotation away from related crops to minimize disease risk and maintain healthy soil ecosystems.
- Some Washington growers mistakenly overlook pest prevention. Aphids and cabbage worms pose significant threats to bok choy, especially in humid areas. Proactive measures, such as using floating row covers and routinely inspecting plants, can save your crops and ensure a bountiful harvest.
- Finally, keep an eye on local climate changes that can impact growth patterns. Washington experience unpredictable weather, including heat waves and late frosts. Always check local forecasts and modify your planting schedules accordingly to ensure successful bok choy growth.
Frequently Asked Questions
What if I'm in a cold pocket of Washington?
If you're in a colder area, such as parts of higher elevation, be cautious about frost dates. In some locations, it might be wise to adjust your indoor starts and outdoor transplant timings by a week or two to account for the last frost.
Can I still plant bok choy in May?
Planting bok choy in early May is possible, particularly in warmer zones like Zone 6b. However, be wary of heat spikes that can lead to bolting. Try focusing on baby varieties for a quick turnaround.
How can I prevent my bok choy from bolting?
To prevent bolting, focus on planting during cooler months in spring and early fall. Keeping consistent moisture levels and providing partial shade during hot weather can significantly help reduce stress and delay flowering.
What are the best companion plants for bok choy?
A few plants suggested for companion planting with bok choy include radishes and cilantro. These plants can help deter pests and promote better growth if paired correctly, though scientific evidence supporting these claims is limited.
What pests should I watch for when growing bok choy?
Aphids and cabbage worms are the most common pests affecting bok choy. Regularly inspect the undersides of leaves for aphid colonies, and employ row covers to minimize cabbage worm damage, ensuring a healthier crop.
Keep Learning
City guides in Washington
Other crops in Washington
Typical fall sowing window for Bok Choy in Washington: August 13 – September 3.