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When to plant winter squash and pumpkins in Ellensburg, WA

Plant winter squash and pumpkins in the garden in Ellensburg May 20 – Jun 10, either as seeds or as young plants started indoors Apr 22–29.

Moderate Plant seeds or young plants

Why these dates

Ellensburg's typical last spring frost is April 28. Frost kills winter squash and pumpkins, and warm-season crops also need warm soil. Soil here stays cold for weeks after the last frost, so planting waits until about May 20.

Inland Northwest. Higher, colder interior valleys. Cold springs and an earlier fall mean a shorter season; quick-maturing varieties pay off.

Difficulty
Moderate
Sun
Full sun
Spacing
4 feet apart (vines spread)
Planting depth
1 inch deep
Frost
Killed by frost
First harvest
About 100 days after planting

Step by step

  1. Start seeds indoors Apr 22–29 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 20 – Jun 10, 4 feet apart (vines spread). 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: Cut when the rind resists a fingernail and the stem is dry, before a hard frost. Cure in a warm room for two weeks.

Varieties that do well here

  • Delicata
  • Sugar Pie pumpkin
  • Sweet Meat (an Oregon heirloom)

Watch out for

A short or cool season. Delicata and other fast varieties ripen far more reliably here than big pumpkins.

Long season. Harvest before hard frost and cure in a warm spot for storage.

Common questions

When is the last frost in Ellensburg, WA?

Typically April 28. In 9 years out of 10, frost is over by May 12. These are 1991–2020 NOAA climate normals for Ellensburg Bowers Field.

Is it too late to plant winter squash and pumpkins in Ellensburg?

The spring planting window runs through June 10. Later plantings may not have time to produce before the first fall frost, which usually arrives around October 7.

When should I start winter squash and pumpkins from seed indoors in Ellensburg?

April 22 to April 29, which is 4 to 3 weeks before the May 20 planting date. Or buy young plants at a garden center instead.

Also plant in Ellensburg around the same time

Planting dates for winter squash and pumpkins in nearby areas

Full planting calendar for Ellensburg · Winter squash and pumpkins in every city