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When to plant onion in Oregon

Oregon spans USDA zones 6b–9b, so the right time to plant onion shifts by weeks across the state. The window to transplant seedlings outdoors runs from about January 14 in Aloha to May 12 in Redmond — below are local dates for 69 cities, each computed from its own frost dates.

In Portlandthe onion transplant out window (January 28–February 11) has passed for this year.
CityZoneLast frostFirst frostTransplant out
Portland8bFebruary 25December 1January 28 – February 11
Eugene8bApril 11October 23March 14 – March 28
Salem8bApril 3November 1March 6 – March 20
Gresham9aMarch 16November 20February 16 – March 2
Hillsboro8bApril 16October 23March 19 – April 2
Bend6bJune 6September 20May 9 – May 23
Beaverton9aApril 1November 6March 4 – March 18
Medford8bApril 8October 29March 11 – March 25

Onion in Oregon: FAQ

When can I plant onion in Oregon?

Across Oregon, the time to transplant onion spans roughly January 14 in Aloha to May 12 in Redmond, each following that city's local frost dates.

Does the onion planting date vary across Oregon?

Yes. Oregon publishes 69 cities with their own frost dates, so the right onion planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.

How long does onion take to grow in Oregon?

Onion takes about 90–110 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.

Planting reminders

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An email when it’s time to start seeds, transplant, and sow — timed to your frost dates. Double opt-in, one-click unsubscribe, no spam.

Onion planting guide →All Oregon cities →Oregon planting calendar →
When to Plant Onion in Oregon — Frost-Based Dates by City — BlissGarden