Rainline Garden

When to plant melons in Walla Walla, WA

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

Tricky here Plant seeds or young plants

Why these dates

Walla Walla's typical last spring frost is March 27. Frost kills melons, 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
Tricky here
Sun
Full sun; the hottest spot you have
Spacing
24 to 36 inches apart
Planting depth
1 inch deep
Frost
Killed by frost
First harvest
About 85 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, 24 to 36 inches apart. 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: Cantaloupes are ripe when the stem slips off with a gentle push. Watermelons are ready when the curly tendril nearest the fruit turns brown and dry.

Varieties that do well here

  • Sugar Baby (watermelon)
  • Minnesota Midget (cantaloupe)
  • Halona (cantaloupe)

Watch out for

Cool soil and cool nights are the main obstacle west of the Cascades. Black plastic mulch and row cover until flowering make the difference.

The toughest heat lover for west-side gardens: choose short-season varieties and use black plastic and row cover. Eastern valleys grow them easily.

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 melons 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 melons 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 melons in nearby areas

Full planting calendar for Walla Walla · Melons in every city