When to plant potatoes in Seattle and Tacoma, WA

Plant seed potatoes in Seattle and Tacoma Mar 15 – Apr 26.

Easy Plant seed potatoes

Why these dates

Seattle and Tacoma's typical last spring frost is March 2. In the west-side valleys, the soil is usually ready for potatoes around March 15.

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: Easy
Sun: Full sun
Spacing: 12 inches apart in rows 30 inches apart
Planting depth: 4 inches deep in a trench
Frost: Handles light frost
First harvest: About 95 days after planting

Step by step

Prepare the bed: loosen the soil and mix in an inch or two of compost.
Plant seed potatoes Mar 15 – Apr 26, 4 inches deep in a trench, 12 inches apart in rows 30 inches apart. Cut large ones into pieces with at least two eyes each.
As plants grow, pile soil or straw around the stems so the potatoes stay covered.
Harvest: Dig new potatoes when the plants flower. For storage potatoes, wait two weeks after the tops die back.

Varieties that do well here

Yukon Gold
German Butterball
Red Norland

Watch out for

Wireworms in beds that were recently lawn. Grow potatoes in an established bed if you can.

Use certified seed potatoes. Hill soil around stems as they grow.

Common questions

When is the last frost in Seattle and Tacoma, WA?

Typically March 2. In 9 years out of 10, frost is over by March 23. These are 1991–2020 NOAA climate normals for Seattle-Tacoma International Airport.

Is it too late to plant potatoes in Seattle and Tacoma?

The spring planting window runs through April 26. Later plantings tend to struggle in summer heat.

How long until I can harvest potatoes?

About 95 days after planting. Dig new potatoes when the plants flower. For storage potatoes, wait two weeks after the tops die back.

Also plant in Seattle and Tacoma around the same time

Planting dates for potatoes in nearby areas

Portland, OR Mar 15 – Apr 26
Gresham, OR Mar 15 – Apr 26
Wilsonville and Canby, OR Mar 15 – Apr 26
Salem, OR Mar 15 – Apr 26
Eugene, OR Mar 15 – Apr 26
Roseburg, OR Mar 15 – Apr 26

Full planting calendar for Seattle and Tacoma · Potatoes in every city