When to plant sunflowers in Walla Walla, WA

Plant sunflowers from seed, directly in the garden in Walla Walla, Apr 25 – Jun 6.

Easy Plant seeds in the ground

Why these dates

Walla Walla's typical last spring frost is March 27. Frost kills sunflowers, 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: Easy
Sun: Full sun
Spacing: 6 inches (small types) to 24 inches (giants) apart
Planting depth: 1 inch deep
Frost: Killed by frost
Flowers: Blooms about 60 to 90 days after sowing

Step by step

Prepare the bed: loosen the soil and mix in an inch or two of compost.
Plant seeds Apr 25 – Jun 6, 1 inch deep, 6 inches (small types) to 24 inches (giants) apart.
Keep the soil evenly moist until sprouts appear, which can take one to three weeks in cool soil.
Harvest: Cut flowers when the petals are just opening. For seeds, let heads dry on the plant until the back turns brown, and cover them from birds.

Varieties that do well here

Mammoth Grey Stripe (giant)
ProCut (for cutting)
Teddy Bear (dwarf)

Watch out for

Birds and slugs eat seedlings. Cover the seedbed until plants are a few inches tall.

Sow them where they'll grow; they dislike transplanting. Tall varieties need a spot out of the wind.

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 sunflowers in Walla Walla?

The spring planting window runs through June 6. Later plantings may not have time to bloom well before the first fall frost, which usually arrives around October 31.

When do sunflowers bloom?

Blooms about 60 to 90 days after sowing. Cut flowers when the petals are just opening. For seeds, let heads dry on the plant until the back turns brown, and cover them from birds.

Also plant in Walla Walla around the same time

Planting dates for sunflowers in nearby areas

Pendleton, OR May 3 – Jun 14
The Dalles, OR Apr 25 – Jun 6
Yakima, WA May 15 – Jun 26
Wenatchee, WA Apr 25 – Jun 6
Tri-Cities (Pasco, Kennewick, Richland), WA May 4 – Jun 15
Moses Lake, WA May 4 – Jun 15

Full planting calendar for Walla Walla · Sunflowers in every city