When to Plant Collard Greens in Washington (2026 Guide)
If you’re planning to grow collard greens in Washington, timing is crucial. Collards are incredibly hardy and can thrive in cooler conditions, making them an excellent choice for our variable climate. In many areas, the last spring frost can be as late as April 20, while temperatures could drop as late as October 26, giving you a long window for successful growth.
Collard greens are not only versatile in the kitchen but also resilient in the garden. These greens can be harvested throughout their growing season, which stretches approximately 200 days in southern Washington. Optimal planting times depend on your specific USDA hardiness zone, which will determine when to start your seeds indoors and when to transplant them.
Understanding your local growing conditions will significantly impact your success with collards. For instance, in Zone 6b, you’ll want to start seeds indoors around February 15 to ensure a healthy plant by the time you’re able to transplant outdoors after the last frost. Paying attention to seasonal changes in your area will enable you to enjoy a bountiful harvest.
Planting Schedule by USDA Zone in Washington
| Zone | Indoor start | Transplant out | Direct sow | Harvest |
|---|---|---|---|---|
| Zone 6b | Start February 15 – March 1, ~6–8 weeks before April 9 | Transplant outdoors after April 9, when the last frost has passed | Direct sow from April 20 to June 1 for a fall harvest | Harvest from June until frost, typically until October 26 |
| Zone 6a | Start February 20 – March 5, ~6–8 weeks before April 20 | Transplant outdoors after April 20, following the last frost | Direct sow from May 1 to June 10 for a late summer harvest | Harvest from June until frost, usually until October 19 |
| Zone 5b | Start March 1 – March 15, ~6–8 weeks before May 6 | Transplant outdoors after May 6, when the danger of frost has passed | Direct sow from May 15 to June 20 for an early fall harvest | Harvest begins in July and can last until the first fall frost, typically around October 3 |
Collard Greens Planting Windows in Washington
- Indoor start: For Washington collard greens, start your seeds indoors from February 15 to March 1.
- Transplant outdoors: Transplant your collard greens outdoors after the last frost date, which is around April 9 in warmer areas.
- Harvest: Expect to begin harvesting your collard greens from June until the first fall frost, which typically occurs around October 26.
Common Mistakes Growing Collard Greens in Washington
- One common error in Washington gardens is planting collards too late in the spring, especially in cooler regions. This can lead to underdeveloped plants before the hot summer months begin. Always check your local frost dates to plan accurately.
- Many gardeners in Washington ignore the risk of late frosts in April and early May. If collards are transplanted too soon, they can suffer damage and halt growth. Wait until after the final frost before planting outdoors to ensure a robust harvest.
- Overwatering is another mistake that can plague collard greens in Washington's wetter regions. Excess water leads to root rot, especially during the rainy seasons. Make sure the soil drains well and doesn't remain soggy during heavy rains.
- A lack of proper nutrition is a frequent pitfall for collard growers. Washington soil may be alkaline or clay-heavy, which can hinder nutrient absorption. Regularly amend the soil with organic matter to improve its structure and nutrient content.
- Failing to rotate crops is detrimental to collard greens, particularly in gardens with a history of brassica family crops. This can lead to soil-borne diseases. Ensure you follow a three-year rotation to maintain soil health and plant vigor.
Frequently Asked Questions
What if I'm in a cold pocket of Washington?
If you're in a colder area, be sure to choose hardy varieties of collard greens and consider starting seeds earlier indoors. You might even try using row covers to help retain heat during the cooler spring nights.
Can I still plant collard greens in May?
Yes, you can plant collards in May, particularly if you're in Zone 5b. Just make sure it’s after the last frost date of May 6 to allow the plants to establish properly for summer growth.
How often should I check for pests on collard greens?
Check your collard plants weekly for signs of aphids and other pests, especially in spring and fall when infestations are more common. A strong spray of water can help dislodge them before they become a serious problem.
Can I harvest collards throughout the summer?
Absolutely! Collards can be harvested continuously throughout the summer months. Just remember to harvest the outer leaves first while allowing the inner leaves to keep growing for a prolonged harvest.
What should I do if my collard greens are spindly?
Spindly collards often indicate insufficient light or overcrowding. Ensure your plants receive full sunlight and are spaced adequately to allow for air circulation, which promotes sturdy growth and reduces disease risk.
Keep Learning
City guides in Washington
Other crops in Washington
Typical fall sowing window for Collard Greens in Washington: August 12 – September 2.