🥬 Can I Plant Mustard Greens in Seattle, WA?
Mustard Greens thrives in cool weather and can be planted now for a fall harvest. Sow seeds soon — they'll be ready around Aug 24–Sep 13, well before the average first frost around Nov 10.
Growing Mustard Greens in Seattle
Seattle's Zone 8b maritime climate is notoriously cool and cloudy, which means warm-season crops like tomatoes and peppers need all the help they can get. A south-facing wall or greenhouse extension is almost essential for tomatoes. On the plus side, cool-season crops like kale, lettuce, and peas absolutely thrive in Seattle's mild, moist conditions.
In Seattle (last frost around March 18), mustard greens can go out around February — approximately 6 weeks before the last expected frost, making it an early-season opportunity.
Mustard Greens thrives between 40°F and 65°F. It tolerates temperatures as low as 25°F, making it a candidate for early spring planting before the last frost date. Expect 25–45 days from transplant to first harvest. Fast-growing cool-season green. Bolts in heat.
Frequently Asked Questions
When can I plant mustard greens in Seattle, WA?
In Seattle (last frost around March 18), mustard greens can go out around February — approximately 6 weeks before the last expected frost, making it an early-season opportunity.
What is the USDA hardiness zone for Seattle?
Seattle, WA is in USDA Plant Hardiness Zone 8b. The last expected spring frost is around March 18, and the first fall frost arrives around November 15. This zone classification helps you understand which perennials survive winter and when annual vegetables can safely go outdoors.
Is it safe to plant mustard greens outside in Seattle right now?
That depends on the current weather forecast. Mustard Greens needs temperatures above 25°F (ideally 40–65°F) to thrive. CanIPlant checks your real 7-day forecast and any active frost alerts to give you a live YES, NO, or WAIT answer — just enter your ZIP code.
Can I grow mustard greens in Seattle 2026?
Yes — Mustard Greens grows well in Seattle, WA. With a Zone 8b climate and a growing season of ~242 days, Seattle is well-suited for cool-season crops like mustard greens. As a frost-tolerant crop, mustard greens can even go out a few weeks before the last frost date.
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