How to Grow Brussels Sprouts

Time it for a cold finish

Brussels sprouts are a cool-season crop that rewards patience. Utah State Extension times them by planting in early summer — early June to late July — so the plants mature as fall temperatures cool, which is when the sprouts develop best. Variety length ranges from about 90 days (Long Island Improved) to 100 (Jade Cross) to 110 (Diablo).

The goal is to have sprouts sizing up in cool weather, not summer heat, so count back from your first-frost date and aim for the plant to be filling out around it. In practice that means setting transplants out well before fall, roughly three months ahead.

Space the plants 12 to 18 inches apart in the row with rows about 2 feet apart; they grow into tall, heavy stalks that may need staking on windy sites. This guide is the whole-crop overview — if your sprouts are forming but loose and leafy rather than tight, the loose-sprouts troubleshooter covers that specific problem.

Topping the plant

Topping is the trick that makes a home crop finish together. When the lower sprouts begin to form — usually mid-to-late August — remove the growing point at the very top of the plant. This stops upward growth and redirects energy into the sprouts, giving more uniform development along the whole stem.

Without topping, the plant keeps stretching taller and the upper sprouts stay tiny while the lower ones are ready, stringing the harvest out unevenly. Topping about three weeks before you want the main harvest concentrates it.

Keep the plants steadily watered and fed through summer; Brussels sprouts are heavy feeders, and stressed plants make loose, bitter sprouts.

Harvest from the bottom up, after frost

The sprouts nearest the base of the stalk mature first. Pick those when they are firm, compact, and about 1 inch in diameter, snapping or twisting them off, and as you clear the bottom the sprouts higher up the stem keep enlarging. A single plant is harvested in passes over several weeks.

Cold is the seasoning. Utah State notes Brussels sprouts taste better after exposure to a few frosts, which concentrate their sugars and improve sweetness — so this is a crop you deliberately leave standing into and past the first frosts.

Harvested sprouts store 2 to 6 months at 32°F and 95% relative humidity. You can also pull whole stalks late in the season and keep them cold with the sprouts attached. For per-plant spacing and planting dates, see the Brussels sprouts calculators.

Sources

Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.

• Utah State University Extension — How to Grow Brussels Sprouts in Your Garden — Plant Brussels sprouts in early summer (early June to late July) for fall maturity so they develop as temperatures cool; varieties run 90 (Long Island Improved) to 110 (Diablo) days; space 12-18 inches between plants in rows 2 feet apart; remove the growing point at the top of the plant when the lower sprouts begin to form (usually mid-late August) for more uniform sprout development; sprouts near the bottom develop first and are harvested at 1 inch diameter, firm and compact, as upper sprouts continue to enlarge; they taste better after a few frosts, which concentrate the sugars; store 2-6 months at 32°F and 95% relative humidity.
• Illinois Extension — Brussels Sprouts (Home Vegetable Gardening) — Brussels sprouts require a long, cool growing season of roughly 90 to 120 days and are grown for a fall harvest; cool weather and light frosts improve flavor by converting starches to sugars; the plant may be topped by removing the growing point to speed and even out sprout development on the lower stem.

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