Rainline Garden

When to plant kohlrabi in Wilsonville and Canby, OR

Plant kohlrabi in the garden in Wilsonville and Canby Mar 15 – Apr 26, either as seeds or as young plants started indoors Feb 1–15. For a fall harvest, plant again Aug 13–27.

Easy Plant seeds or young plants

Why these dates

Wilsonville and Canby's typical last spring frost is March 16. As a cool-season crop that handles light frost, this crop doesn't need to wait for that date. In the west-side valleys, though, the soil usually isn't ready to work until about March 15.

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
Thin to 6 inches apart
Planting depth
¼ to ½ inch deep
Frost
Handles light frost
First harvest
About 55 days after planting

Step by step

  1. Start seeds indoors Feb 1–15 in trays or small pots under a grow light or in your sunniest window. Or skip this step and buy young plants (starts) at a garden center.
  2. Harden off the young plants: about a week before planting, set them outside for a few hours a day, a little longer each day.
  3. Plant them in the garden Mar 15 – Apr 26, Thin to 6 inches apart. If you plant seeds instead, sow them ¼ to ½ inch deep.
  4. Water deeply once or twice a week rather than a little every day, and mulch once the soil is warm.
  5. Plant again Aug 13–27 for a fall harvest.
  6. Harvest: Cut bulbs at 2 to 3 inches across. Peel off the tough skin and eat raw or cooked.

Varieties that do well here

  • Kolibri (purple)
  • Winner
  • Kossak (large, stores well)

Watch out for

Cabbage worms chew the leaves. Insect netting keeps the white moths from laying eggs.

Pick when the bulb is about tennis-ball size; bigger ones turn woody.

Common questions

When is the last frost in Wilsonville and Canby, OR?

Typically March 16. In 9 years out of 10, frost is over by April 7. These are 1991–2020 NOAA climate normals for Aurora State Airport.

Is it too late to plant kohlrabi in Wilsonville and Canby?

The spring planting window runs through April 26. If you miss it, plant again for fall from August 13 to August 27.

When should I start kohlrabi from seed indoors in Wilsonville and Canby?

February 1 to February 15, which is 6 to 4 weeks before the March 15 planting date. Or buy young plants at a garden center instead.

Also plant in Wilsonville and Canby around the same time

Planting dates for kohlrabi in nearby areas

Full planting calendar for Wilsonville and Canby · Kohlrabi in every city