When to plant Brussels sprouts in Astoria, OR

Start Brussels sprouts from seed indoors Feb 4–18, then plant the young plants in the garden in Astoria Apr 1 – May 13.

Moderate Plant young plants (starts)

Why these dates

Astoria's typical last spring frost is March 26. On the coast, the soil is usually ready for Brussels sprouts around April 1.

Coast. Mild winters but cool, foggy summers. Frost is rarely the problem; warmth is. Pick early, cool-tolerant varieties of tomatoes and squash.

Start seeds indoors Feb 4–18 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.
Harden off the young plants: about a week before planting, set them outside for a few hours a day, a little longer each day.
Plant them in the garden Apr 1 – May 13, 24 inches apart. Plant starts at the depth they grew in the pot.
Water deeply once or twice a week rather than a little every day, and mulch once the soil is warm.
Harvest: Pick sprouts from the bottom of the stalk up once they're firm and about an inch across. Frost improves the flavor.

Aphids cluster on the sprouts in late summer. Knock them off with a strong spray of water every few days.

A long-season crop picked in fall and winter, when frost sweetens the sprouts. West of the Cascades, plants keep producing well into winter.

When is the last frost in Astoria, OR?

Typically March 26. In 9 years out of 10, frost is over by April 18. These are 1991–2020 NOAA climate normals for Astoria Regional Airport.

Is it too late to plant Brussels sprouts in Astoria?

The spring planting window runs through May 13. Later plantings tend to struggle in summer heat.

When should I start Brussels sprouts from seed indoors in Astoria?

February 4 to February 18, which is 8 to 6 weeks before the April 1 planting date. Or buy young plants at a garden center instead.