🌸 Can I Plant Rhubarb in Seattle, WA?

2026 planting guide for Zone 8b · Last frost ~March 18 · Growing season ~242 days

✅ YES — Good temps, but watch for heat — highs near 86°F

Temperature conditions are suitable for Rhubarb. Highs near 86°F are on the warm side — make sure plants have plenty of water.

Planting window: Jul 16 – Jul 30
Good to plant now — rhubarb is a perennial, so expect first harvest in 2027.
Live result based on current forecast for Seattle, WA · Updates every 6 hours
USDA Zone
8b
Last Spring Frost
~March 18
First Fall Frost
November 15
Growing Season
~242 days
Ideal Temp for Rhubarb
40–75°F
Frost Risk
✅ Tolerant

Growing Rhubarb 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), rhubarb can go out around March — approximately 2 weeks before the last expected frost, making it an early-season opportunity.

Rhubarb thrives between 40°F and 75°F. It tolerates temperatures as low as 20°F, making it a candidate for early spring planting before the last frost date. Expect 365–730 days from transplant to first harvest. Do not harvest in the first year. Leaves are toxic — eat stalks only. Thrives with cold winters.

Frequently Asked Questions

When can I plant rhubarb in Seattle, WA?

In Seattle (last frost around March 18), rhubarb can go out around March — approximately 2 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 rhubarb outside in Seattle right now?

That depends on the current weather forecast. Rhubarb needs temperatures above 20°F (ideally 40–75°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 rhubarb in Seattle 2026?

Yes — Rhubarb 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 rhubarb. As a frost-tolerant crop, rhubarb can even go out a few weeks before the last frost date.

Grow Rhubarb in Other Cities

New York, NYLos Angeles, CAChicago, ILHouston, TXPhoenix, AZPhiladelphia, PASan Antonio, TXSan Diego, CA

Get a live answer for your exact address

Enter your ZIP code — CanIPlant checks your real 7-day forecast, frost alerts, and 30-year climate data to tell you whether to plant rhubarb right now.

Check My ZIP Code →