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A pile of fresh Brussels sprouts

Oregon · Washington · Idaho

When to plant Brussels sprouts

Plant in the garden: Portland and Seattle Mar 15 – Apr 26; Spokane Apr 15 – May 27; Boise Apr 1 – May 13; Bend May 12 – Jun 23.

Brussels sprouts are a tall cabbage-family plant that grows small, cabbage-like buds all along its stem, ripening from the bottom up. Roasting brings out their nutty sweetness, and the leafy tops are edible like collards. Modern varieties are noticeably milder than the bitter sprouts many people remember.

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Puts Brussels sprouts on your free plan, with dates for your town and a spot in your beds.

Difficulty
Moderate
Sun
Full sun
Spacing
24 inches apart
Planting depth
Plant starts at the depth they grew in the pot
Frost
Handles light frost
First harvest
About 100 days after planting

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

Brussels sprout planting dates

TownsStart seeds indoorsPlant in the garden
Portland, OR, Seattle and Tacoma, WAJan 18 – Feb 1Mar 15 – Apr 26
Spokane, WAFeb 18 – Mar 4Apr 15 – May 27
Boise and Meridian, ID, Astoria, ORFeb 4–18Apr 1 – May 13
Bend and Redmond, ORMar 17–31May 12 – Jun 23

Dates for six main cities. For any of the other 80 towns, type it in the box at the top of the page or browse all towns.

Brussels sprout year at a glance

TaskJFMAMJJASOND
Start indoorsJanFeb
PlantMarApr
HarvestJanFebOctNovDec

Around Portland. Colder towns, especially east of the Cascades, run a few weeks later; the table above has your town's planting dates.

How to grow Brussels sprouts

  1. Start seeds indoors on your city's dates 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 on your city's dates, 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. Harvest: Pick sprouts from the bottom of the stalk up once they're firm and about an inch across. Frost improves the flavor.

Growing Brussels sprouts in your part of the Northwest

The same plant behaves differently on the wet west side, the foggy coast and the dry, colder east side.

West-side valleys

Willamette Valley, Puget Sound, southern Oregon

Brussels sprouts are well suited to the west side: plants set out in early summer stand through fall frosts, which sweeten the sprouts, and keep producing into winter. Aphids hide in the sprouts, so check early.

Coast

Oregon and Washington coast

The long, cool season suits Brussels sprouts, and harvest often runs well into winter.

East of the Cascades

Columbia Basin, Yakima, Boise, Spokane, north Idaho

Summer heat stresses young plants and brings aphids. Set out transplants in early summer so sprouts form during cooler fall weather.

High desert and mountain towns

Central Oregon, high eastern Oregon valleys, McCall, Salmon

The season can be too short for late varieties, so choose early ones. Plants handle hard frosts in fall.

More Brussels sprout varieties

More widely sold picks that do well somewhere in the Northwest. The tag says which part of the Northwest suits each one best.

Long Island Improved

Heirloom, open-pollinated · 90 days

The classic heirloom on compact plants about 2 feet tall. Yields are modest compared with hybrids, but it is hardy, inexpensive and sweetens nicely after frost.

Both sides

Diablo

Hybrid, late · 110 days

Tall, sturdy plants with heavy yields of large, smooth sprouts. A late variety that holds well in the garden for fall and early winter picking.

Both sides

Churchill

Hybrid, early · 90 days

Early and adaptable, with uniform, sweet, medium sprouts. A good pick where fall arrives quickly, and it handles a range of weather well.

Both sides

Jade Cross

Hybrid, compact · 90 days

An award-winning hybrid known for reliability and tolerance of summer heat. Compact plants produce plenty of blue-green sprouts. It is a solid choice for gardeners who want a dependable fall harvest.

Both sides

Falstaff

Red-purple sprouts · 100 days

Purple-red sprouts that keep much of their color when lightly cooked. The flavor is mild and nutty, and cold weather deepens the color.

Both sides

Red Rubine

Heirloom, red · 105 days

An old red variety with deep purple sprouts and leaves. Yields are lower than green hybrids, but the color and mild flavor make it a striking garden plant.

Both sides

How much to grow

How many to plant

For a family of four, 6 to 8 plants.

What to expect

About 1 to 2 pounds of sprouts per plant.

Storing the harvest

Sprouts on the stalk keep two to three weeks in a cold spot. Blanch and freeze extras.

What to plant after Brussels sprouts

Around Portland, the Brussels sprout harvest wraps up around February. These crops can still go into the same bed, and they come from a different plant family, which helps with rotation.

Portland dates. Pick your town at the top of the page for yours.

Key numbers

Top care tip: Water steadily through summer and pull off yellowing lower leaves as sprouts form up the stalk.

Growing notes

What makes the difference in Northwest gardens, in plain language.

Soil and long-season feeding

Brussels sprouts stand in the garden for months, so they need deep, rich soil with plenty of compost and a pH of about 6.0 to 7.5. Feed at planting and side-dress once or twice during summer, but don't overdo the nitrogen late in the season, since that can give loose sprouts. Plants grow tall and top-heavy, so firm the soil well around transplants and stake them in windy spots. Mulch to keep soil evenly moist through the dry Northwest summer.

Timing and topping

Sprouts taste best when they mature in cool fall weather, because frost converts starches into sugars. Plant starts in late spring or early summer so the main harvest comes in fall and winter. About a month before you want to pick, you can pinch out the growing tip at the top of the stalk. This "topping" stops the plant growing taller and sends energy into the sprouts, so they size up more evenly. West of the Cascades, plants keep producing into winter. East of the Cascades, harvest before the deepest cold, though plants handle hard frost well.

Aphids and harvest

Gray cabbage aphids are the main pest. They hide between the sprouts and in leaf folds in late summer, protected by a waxy coating. Spray them off with water every few days, and remove badly infested leaves. Beneficial insects often catch up by fall. Pick sprouts from the bottom up when they are firm and about an inch across, snapping off the yellowing leaves below them as you go. Sprouts keep a week or two in the fridge, or longer if you cut the whole stalk and keep it cool.

Good neighbors and crop rotation

Good neighbors

  • Lettuce. Grows under young plants in spring.
  • Onions. Fit around the base.

Keep apart

  • Other cabbage-family crops in the same bed every year. Shared pests and clubroot build up; rotate.

Cabbage family: Grow cabbage-family crops in a different bed each year and come back to the same spot only every three or four years. Clubroot, which swells and knots the roots, lives in the soil for many years once it arrives, and root maggot pupae wait in last year's bed.

Pests and problems

What most often goes wrong with Brussels sprouts in Northwest gardens, how to spot it and what to do.

Gray aphids

Signs: Waxy gray clusters on sprouts in late summer.

What to do: Hose them off every few days and pick off bad leaves.

Loose, open sprouts

Signs: Sprouts stay leafy and never firm up.

What to do: Firm soil at planting and steady water; wait for cool fall weather to firm them.

Cabbage worms

Signs: Holes in the leaves.

What to do: Insect netting from planting.

Common questions about growing Brussels sprouts

When should I plant Brussels sprouts in Oregon, Washington and Idaho?

Plant in the garden: Mar 15 – Apr 26 in Portland and Seattle, Apr 15 – May 27 in Spokane, Apr 1 – May 13 in Boise and May 12 – Jun 23 in Bend. Pick your town at the top of the page for your own dates.

Why are my Brussels sprouts loose and leafy?

Hot weather while sprouts form, too much late nitrogen, or uneven watering can all cause loose sprouts. Time planting so they mature in cool fall weather. Topping the plant a month before harvest also helps them firm up.

Should I cut the top off my Brussels sprouts?

You can. Pinching out the top growing tip about a month before harvest makes the sprouts mature more evenly. If you prefer a longer harvest over winter, leave the top on.

Do Brussels sprouts need frost?

They don't need it, but a few light frosts make them noticeably sweeter. That's why fall and winter harvests are the best. Mature plants tolerate hard frosts well.

More cabbage family

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