When to plant onions in Pendleton, OR

Plant onion sets in Pendleton Mar 20 – Apr 24.

Moderate Plant small onion bulbs (sets)

Why these dates

Pendleton's typical last spring frost is April 26. As a cool-season crop that handles light frost, this crop doesn't need to wait for that date. In the Columbia Basin and low eastern valleys, though, the soil usually isn't ready to work until about March 20.

Columbia Basin and low eastern valleys. Hot, dry summers and quick spring warm-up. Warm crops go in earlier than west of the Cascades, and irrigation matters more than rain.

Difficulty: Moderate
Sun: Full sun
Spacing: 4 inches apart
Planting depth: Sets 1 inch deep, tip just showing
Frost: Handles light frost
First harvest: About 110 days after planting

Step by step

Prepare the bed: loosen the soil and mix in an inch or two of compost.
Plant onion sets Mar 20 – Apr 24, 4 inches apart, sets 1 inch deep, tip just showing.
Water regularly and keep the bed weeded; onions don't compete well.
Harvest: When the tops flop over in late summer, pull the onions and let them dry in a shady, airy spot for two weeks.

Varieties that do well here

Walla Walla Sweet
Copra (stores well)
Redwing

Watch out for

Weeds outcompete onions' thin leaves. Keep the bed weeded and mulched.

Plant as soon as the soil is dry enough to work. Pick long-day varieties for the Northwest.

Common questions

When is the last frost in Pendleton, OR?

Typically April 26. In 9 years out of 10, frost is over by May 10. These are 1991–2020 NOAA climate normals for Pendleton Airport.

Is it too late to plant onions in Pendleton?

The spring planting window runs through April 24. Later plantings tend to struggle in summer heat.

How long until I can harvest onions?

About 110 days after planting. When the tops flop over in late summer, pull the onions and let them dry in a shady, airy spot for two weeks.

Also plant in Pendleton around the same time

Planting dates for onions in nearby areas

The Dalles, OR Mar 20 – Apr 24
Yakima, WA Mar 27 – May 1
Wenatchee, WA Mar 20 – Apr 24
Tri-Cities (Pasco, Kennewick, Richland), WA Mar 20 – Apr 24
Walla Walla, WA Mar 20 – Apr 24
Moses Lake, WA Mar 20 – Apr 24

Full planting calendar for Pendleton · Onions in every city