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A white cauliflower head forming in the middle of a leafy plant
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When to plant cauliflower in Tri-Cities (Pasco, Kennewick, Richland), WA

Start cauliflower from seed indoors Feb 11–25, then plant the young plants in the garden in Tri-Cities (Pasco, Kennewick, Richland) Apr 1–29. For a fall harvest, plant again Jul 12–26.

Tricky here Plant young plants (starts)

Why these dates

Tri-Cities (Pasco, Kennewick, Richland)'s typical last spring frost is April 27. As a cool-season crop that handles light frost, this crop doesn't need to wait for that date. In the Columbia Basin and low eastern valleys, though, the soil usually isn't ready to work until about April 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
Spacing
18 to 24 inches apart
Planting depth
Plant starts at the depth they grew in the pot
Frost
Handles light frost
First harvest
About 75 days after planting

Step by step

  1. Start seeds indoors Feb 11–25 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 Apr 1–29, 18 to 24 inches apart. Plant starts at the depth they grew in the pot.
  4. Water deeply once or twice a week rather than a little every day, and mulch once the soil is warm.
  5. Plant again Jul 12–26 for a fall harvest.
  6. Harvest: Cut the head while it's firm and tight, before the curds start to separate. Tie the outer leaves over young heads to keep them white.

Varieties that do well here

  • Snow Crown
  • Amazing
  • Graffiti (purple)

Watch out for

A cold snap or dry spell makes plants form tiny 'button' heads. Keep the soil evenly moist and don't rush spring planting.

Fussier than broccoli: a setback from a cold snap or dry soil makes tiny 'button' heads. Fall crops are often the most reliable here.

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 cauliflower in Tri-Cities (Pasco, Kennewick, Richland)?

The spring planting window runs through April 29. If you miss it, plant again for fall from July 12 to July 26.

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

February 11 to February 25, which is 7 to 5 weeks before the April 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 cauliflower in nearby areas

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