Rainline Garden

When to plant potatoes in Tri-Cities (Pasco, Kennewick, Richland), WA

Plant seed potatoes in Tri-Cities (Pasco, Kennewick, Richland) Apr 1 – May 13.

Easy Plant seed potatoes

Why these dates

Tri-Cities (Pasco, Kennewick, Richland)'s typical last spring frost is April 27. 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 April 1.

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
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

  1. Prepare the bed: loosen the soil and mix in an inch or two of compost.
  2. Plant seed potatoes Apr 1 – May 13, 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.
  3. As plants grow, pile soil or straw around the stems so the potatoes stay covered.
  4. 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 Tri-Cities (Pasco, Kennewick, Richland), WA?

Typically April 27. In 9 years out of 10, frost is over by May 10. These are 1991–2020 NOAA climate normals for Pasco Tri-Cities Airport.

Is it too late to plant potatoes in Tri-Cities (Pasco, Kennewick, Richland)?

The spring planting window runs through May 13. 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 Tri-Cities (Pasco, Kennewick, Richland) around the same time

Planting dates for potatoes in nearby areas

Full planting calendar for Tri-Cities (Pasco, Kennewick, Richland) · Potatoes in every city