🥒 Can I Plant Cucumber in Seattle, WA?
Cucumber needs nights consistently above 55°F to thrive. Current forecast lows of ~51°F are below that threshold. Wait for warmer overnight temperatures.
Growing Cucumber 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), aim to direct sow or transplant cucumber outside around April — approximately 2 weeks after your last expected frost. Starting seeds indoors 3 weeks before the last frost date gives you a significant head start.
Cucumber thrives between 65°F and 95°F. It is frost-sensitive, meaning a single freeze at 32°F will damage or kill it — always wait until frost danger has fully passed. Expect 50–70 days from transplant to first harvest. Warm soil required. Direct sow preferred.
Frequently Asked Questions
When can I plant cucumber in Seattle, WA?
In Seattle (last frost around March 18), aim to direct sow or transplant cucumber outside around April — approximately 2 weeks after your last expected frost. For best results, start seeds indoors 3 weeks before that — giving you strong transplants ready to go out at the right time.
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 cucumber outside in Seattle right now?
That depends on the current weather forecast. Cucumber needs temperatures above 55°F (ideally 65–95°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 cucumber in Seattle 2026?
Yes — Cucumber grows well in Seattle, WA. With a Zone 8b climate and a growing season of ~242 days, Seattle is well-suited for warm-season crops like cucumber. Just wait until after the last frost (around March 18) before moving plants outside.
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