Rainline Garden

When to plant sunflowers in Roseburg, OR

Plant sunflowers from seed, directly in the garden in Roseburg, May 10 – Jun 21.

Easy Plant seeds in the ground

Why these dates

Roseburg's typical last spring frost is March 19. 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 May 10.

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
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

  1. Prepare the bed: loosen the soil and mix in an inch or two of compost.
  2. Plant seeds May 10 – Jun 21, 1 inch deep, 6 inches (small types) to 24 inches (giants) apart.
  3. Keep the soil evenly moist until sprouts appear, which can take one to three weeks in cool soil.
  4. 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 Roseburg, OR?

Typically March 19. In 9 years out of 10, frost is over by April 13. These are 1991–2020 NOAA climate normals for Roseburg Regional Airport.

Is it too late to plant sunflowers in Roseburg?

The spring planting window runs through June 21. Later plantings may not have time to bloom well before the first fall frost, which usually arrives around November 20.

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 Roseburg around the same time

Planting dates for sunflowers in nearby areas

Full planting calendar for Roseburg · Sunflowers in every city