Brussels Sprouts.jpeg

Brussels Sprouts

When to Plant

To determine the optimum planting time, count backwards from your first fall frost date using the "days to maturity" listed on the seed packet. Generally, this means sowing Brussels sprout seeds about 4 months before your first fall frost date.

  • In regions with cold winters, where winter temperatures are often below freezing, start seeds in early to mid-summer. Plants will mature for a mid-fall or early winter harvest. 

  • In regions with mild or warm winters, where winter temperatures are occasionally or rarely below freezing, start seeds in mid- to late summer. Plants will mature for a mid- to late winter harvest.

Brussels sprouts may be started from seed indoors or sown directly into the garden. We recommend starting seeds indoors, as this gives seedlings a headstart and helps to protect them from summer heat and pests. Direct-sown seeds can take a few weeks longer to mature, so add 20 days to your planting date calculation if you plan to sow outdoors. (In other words, sow seeds outdoors about 20 days earlier than if you were starting them indoors.)

Choosing a Planting Site

  • Raised beds are especially recommended for cool-season vegetables, especially in the spring and fall, when temperatures are not consistent.

  • Work several inches of aged manure and/or compost into the soil a few days before sowing or transplanting.

  • Brussels sprout plants usually reach heights of 2 to 3 feet, so plan accordingly; they may require staking.

How to Plant

  • Sow seeds about ½ inch deep.

  • If direct sowing seeds outdoors, sow seeds about 2 to 3 inches apart. (Seedling should be thinned to 12 to 24 inches apart when they reach about 6 inches tall.)

  • Plant transplanted seedlings 12 to 24 inches apart.

  • Water well at time of transplanting.

How to Grow

  • Thin young plants to 12 to 24 inches apart when they reach 6 inches tall.

  • Fertilize with a nitrogen-rich product after thinning. Repeat every 3 to 4 weeks.

  • Mulch to retain moisture and keep the soil temperature cool through summer.

  • If growing during hot weather, be sure to keep the plants well watered. Inconsistent moisture can lead to subpar sprout development. Brussels sprouts should receive about 1 to 1½ inches of water per square foot per week.

  • Consider using row covers to protect young plants from pests. Brussels sprouts are usually planted outdoors right when pests are at their worst!

  • Do not disturb the soil around the plants; roots are shallow and susceptible to damage.

  • Remove yellowing leaves at the bottom of the plant to allow for more sunlight on the stalk and to focus plant energy on healthy growth.

  • To encourage plants to mature faster, cut off the top leaves 3 to 4 weeks before harvest.

  • Note: If you intend to harvest sprouts into winter, leave the top leaves of the plant intact; they provide protection from snow.

  • Cover plants with 10 to 12 inches of mulch if you plan to harvest into the winter.

Pests/Diseases

  • Aphids 

  • Black Rot

  • Cabbage Loopers

  • Cabbage Root Maggots 

  • Cabbage Worms

  • Clubroot

  • Downy Mildew

  • Flea Beetles

  • White Mold

How to Harvest

  • Sprouts mature from the bottom of the stalk upwards. Harvest sprouts from the bottom when they reach about 1 inch in diameter.

  • If desired, after a moderate frost, pull up the entire stalk, roots and all. (Remove leaves first.) Then hang stalk upside down in a cool, dry basement or garage or barn.

  • Store stalks (no roots) for about 1 month in a root cellar or basement.