Rainline Garden

When to plant cucumbers in Tri-Cities (Pasco, Kennewick, Richland), WA

Plant cucumbers in the garden in Tri-Cities (Pasco, Kennewick, Richland) May 1–29, either as seeds or as young plants started indoors Apr 3–10.

Moderate Plant seeds or young plants

Why these dates

Tri-Cities (Pasco, Kennewick, Richland)'s typical last spring frost is April 27. Frost kills cucumbers, so planting starts once frost risk drops, around May 1. Keep row cover or a frost blanket handy for the first couple of weeks, since a late frost is still possible.

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
12 inches apart on a trellis
Planting depth
1 inch deep
Frost
Killed by frost
First harvest
About 60 days after planting

Step by step

  1. Start seeds indoors Apr 3–10 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 May 1–29, 12 inches apart on a trellis. If you plant seeds instead, sow them 1 inch deep.
  4. Water deeply once or twice a week rather than a little every day, and mulch once the soil is warm.
  5. Harvest: Pick slicers at 6 to 8 inches, before they yellow. Check plants every day or two in midsummer.

Varieties that do well here

  • Marketmore 76
  • Lemon
  • Diva

Watch out for

Powdery mildew in late summer. Grow them up a trellis for airflow and water at the base.

Need warm soil and warm nights. Floating row cover helps in cool springs.

Common questions

When is the last frost in Tri-Cities (Pasco, Kennewick, Richland), WA?

Typically April 27. In 9 years out of 10, frost is over by May 10. These are 1991–2020 NOAA climate normals for Pasco Tri-Cities Airport.

Is it too late to plant cucumbers in Tri-Cities (Pasco, Kennewick, Richland)?

The spring planting window runs through May 29. Later plantings may not have time to produce before the first fall frost, which usually arrives around October 11.

When should I start cucumbers from seed indoors in Tri-Cities (Pasco, Kennewick, Richland)?

April 3 to April 10, which is 4 to 3 weeks before the May 1 planting date. Or buy young plants at a garden center instead.

Also plant in Tri-Cities (Pasco, Kennewick, Richland) around the same time

Planting dates for cucumbers in nearby areas

Full planting calendar for Tri-Cities (Pasco, Kennewick, Richland) · Cucumbers in every city