When to plant sweet corn in Walla Walla, WA

Plant sweet corn from seed, directly in the garden in Walla Walla, Apr 25 – May 30.

Moderate Plant seeds in the ground

Why these dates

Walla Walla's typical last spring frost is March 27. Frost kills sweet corn, and warm-season crops also need warm soil. Soil here stays cold for weeks after the last frost, so planting waits until about April 25.

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: 10 inches apart in a block of short rows
Planting depth: 1 inch deep
Frost: Killed by frost
First harvest: About 80 days after planting

Step by step

Prepare the bed: loosen the soil and mix in an inch or two of compost.
Plant seeds Apr 25 – May 30, 1 inch deep, 10 inches apart in a block of short rows.
Keep the soil evenly moist until sprouts appear, which can take one to three weeks in cool soil.
Harvest: Ready about three weeks after the silks appear, when the silks are brown and the kernels squirt milky juice.

Varieties that do well here

Early Sunglow
Bodacious
Golden Bantam

Watch out for

Crows pull up sprouting seeds. Cover the bed with netting or row cover until plants are 4 inches tall.

Plant in blocks of at least four short rows, not one long row, for good pollination.

Common questions

When is the last frost in Walla Walla, WA?

Typically March 27. In 9 years out of 10, frost is over by April 22. These are 1991–2020 NOAA climate normals for Walla Walla Regional Airport.

Is it too late to plant sweet corn in Walla Walla?

The spring planting window runs through May 30. Later plantings may not have time to produce before the first fall frost, which usually arrives around October 31.

How long until I can harvest sweet corn?

About 80 days after planting. Ready about three weeks after the silks appear, when the silks are brown and the kernels squirt milky juice.

Also plant in Walla Walla around the same time

Planting dates for sweet corn in nearby areas

Pendleton, OR May 3 – Jun 7
The Dalles, OR Apr 25 – May 30
Yakima, WA May 15 – Jun 19
Wenatchee, WA Apr 25 – May 30
Tri-Cities (Pasco, Kennewick, Richland), WA May 4 – Jun 8
Moses Lake, WA May 4 – Jun 8

Full planting calendar for Walla Walla · Sweet corn in every city