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When to plant winter squash and pumpkins in Walla Walla, WA

Plant winter squash and pumpkins in the garden in Walla Walla May 1–22, either as seeds or as young plants started indoors Apr 3–10.

Moderate Plant seeds or young plants

Why these dates

Walla Walla's typical last spring frost is March 27. 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 1.

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
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 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 1–22, 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 Walla Walla, WA?

Typically March 27. In 9 years out of 10, frost is over by April 22. These are 1991–2020 NOAA climate normals for Walla Walla Regional Airport.

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

The spring planting window runs through May 22. Later plantings may not have time to produce before the first fall frost, which usually arrives around October 31.

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

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 Walla Walla around the same time

Planting dates for winter squash and pumpkins in nearby areas

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