When to plant onions in Bellingham, WA

Plant onion sets in Bellingham Mar 1 – Apr 5.

Moderate Plant small onion bulbs (sets)

Why these dates

Bellingham's typical last spring frost is March 31. As a cool-season crop that handles light frost, this crop doesn't need to wait for that date. In the west-side valleys, though, the soil usually isn't ready to work until about March 1.

West-side valleys. The Willamette Valley, Puget Sound and southern Oregon valleys. Long frost-free seasons, but soil stays cold and wet into May, so warm crops wait for warm soil, not just the last frost.

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 1 – Apr 5, 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 Bellingham, WA?

Typically March 31. In 9 years out of 10, frost is over by April 18. These are 1991–2020 NOAA climate normals for Bellingham International Airport.

Is it too late to plant onions in Bellingham?

The spring planting window runs through April 5. 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 Bellingham around the same time

Planting dates for onions in nearby areas

Portland, OR Mar 1 – Apr 5
Gresham, OR Mar 1 – Apr 5
Wilsonville and Canby, OR Mar 1 – Apr 5
Salem, OR Mar 1 – Apr 5
Eugene, OR Mar 1 – Apr 5
Roseburg, OR Mar 1 – Apr 5

Full planting calendar for Bellingham · Onions in every city