🧅 Can I Plant Green Onion in Portland, OR?
Temperature conditions are suitable for Green Onion. Highs near 88°F are on the warm side — make sure plants have plenty of water. The season is running warmer than normal, which has opened this window earlier than usual.
Growing Green Onion in Portland
Portland's Zone 8b Willamette Valley climate is excellent for many crops, but the famously cloudy, cool summers challenge heat-loving plants. Tomatoes, peppers, and melons need the warmest microclimate in your yard. Cool-season crops — kale, chard, lettuce, brassicas — are where Portland gardens truly shine, often producing well into December.
In Portland (last frost around March 25), green onion can go out around February — approximately 4 weeks before the last expected frost, making it an early-season opportunity. Starting seeds indoors 8 weeks before the last frost date gives you a significant head start.
Green Onion thrives between 50°F and 80°F. It tolerates temperatures as low as 35°F, making it a candidate for early spring planting before the last frost date. Expect 60–80 days from transplant to first harvest. Easy and fast. Direct sow in early spring or fall. Harvest young.
Frequently Asked Questions
When can I plant green onion in Portland, OR?
In Portland (last frost around March 25), green onion can go out around February — approximately 4 weeks before the last expected frost, making it an early-season opportunity. For best results, start seeds indoors 8 weeks before that — giving you strong transplants ready to go out at the right time.
What is the USDA hardiness zone for Portland?
Portland, OR is in USDA Plant Hardiness Zone 8b. The last expected spring frost is around March 25, 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 green onion outside in Portland right now?
That depends on the current weather forecast. Green Onion needs temperatures above 35°F (ideally 50–80°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 green onion in Portland 2026?
Yes — Green Onion grows well in Portland, OR. With a Zone 8b climate and a growing season of ~235 days, Portland is well-suited for warm-season crops like green onion. As a frost-tolerant crop, green onion can even go out a few weeks before the last frost date.
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