Rainline Garden

When to plant dahlias in Klamath Falls, OR

Plant dahlia tubers in Klamath Falls Jun 9 – Jul 7.

Moderate Plant tubers

Why these dates

Klamath Falls's typical last spring frost is June 9. Frost kills dahlias, so planting starts once frost risk drops, around June 9. Keep row cover or a frost blanket handy for the first couple of weeks, since a late frost is still possible. The season is a little tight here, so an early variety is the safer choice.

High desert and mountains. Central and high eastern Oregon. Frost is possible almost any month. Use row covers, wall-o-water or cloches for warm crops, and choose short-season varieties.

Difficulty
Moderate
Sun
Full sun
Spacing
18 to 24 inches apart
Planting depth
4 to 6 inches deep, eye pointing up
Frost
Killed by frost
Flowers
Blooms from midsummer until the first frost

Step by step

  1. Pick a sunny spot with soil that drains well, and mix in an inch or two of compost.
  2. Plant dahlia tubers Jun 9 – Jul 7, 18 to 24 inches apart. 4 to 6 inches deep, eye pointing up.
  3. Don't water tubers until shoots appear, then water deeply once a week. Stake tall varieties when you plant so you don't spear the tuber later.
  4. Harvest: Cut flowers when they're almost fully open, early in the morning. The more you cut, the more they bloom.

Varieties that do well here

  • Café au Lait
  • Bishop of Llandaff
  • Cornel Brons

Watch out for

Slugs and earwigs chew young shoots and petals. Use iron phosphate slug bait early in the season.

Tubers rot in cold, wet soil, so wait until it warms. West of the Cascades many gardeners leave them in the ground over winter under thick mulch; east of the mountains, dig and store them after the first frost.

Common questions

When is the last frost in Klamath Falls, OR?

Typically June 9. In 9 years out of 10, frost is over by June 26. These are 1991–2020 NOAA climate normals for Klamath Falls Airport.

Is it too late to plant dahlias in Klamath Falls?

The spring planting window runs through July 7. Later plantings may not have time to bloom well before the first fall frost, which usually arrives around September 18.

When do dahlias bloom?

Blooms from midsummer until the first frost. Cut flowers when they're almost fully open, early in the morning. The more you cut, the more they bloom.

Also plant in Klamath Falls around the same time

Planting dates for dahlias in nearby areas

Full planting calendar for Klamath Falls · Dahlias in every city