How to Grow Brussels Sprouts: The Complete Guide

Photo Credit
Pixabay
Botanical Name
Brassica oleracea
Plant Type
Sun Exposure

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Planting, Growing, and Harvesting Brussels Sprouts

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Learn how to grow brussels sprouts, a cool-weather crop that is planted in early spring or mid- to late summer for a crop that matures in the fall. These nutritious vegetables taste even better after a few light frosts! Here’s how to plant, grow, and harvest brussels sprouts in your garden.

About Brussels Sprouts

Named for Brussels, Belgium, where they were first cultivated in the 16th century, brussels sprouts are a vegetable that is commonly seen in the grocery store, but not-as-commonly seen in the home garden. This is probably because they aren’t the easiest vegetable to grow! They require a fairly long growing season (80–100 days to harvest) and are a cool-season crop, meaning that they produce best when grown for a fall or early winter harvest. The sprouts improve in flavor after a light frost or two. 

As long as you plant them at the right time, keep them cool and well watered during the heat of summer, and protect them from pests, brussels sprouts are a rewarding vegetable crop to grow—an accomplishment!

Brussels sprouts are a cultivar (cultivated variety) of wild cabbage, Brassica oleracea, which is the same plant species that cabbage, broccoli, cauliflower, kale, kohlrabi, and a number of other popular food crops stem from. Over generations and generations, this versatile plant has been bred in different ways to highlight its different features—flowers, leaves, buds, stem, and root—to provide us with a wide variety of foods! Brussels sprouts form as buds along the main stem of the plant, just above each leaf axil. 

Brussels sprouts close up.

Planting

Choose a planting site that gets full sun (6 to 8 hours of direct sunlight per day). Raised beds are especially recommended for cool-season vegetables, especially in the spring and fall, when temperatures are not consistent.

Soil should be well-draining and moderately fertile. Work several inches of aged manure and/or compost into the soil to improve soil fertility and texture.

When to Plant Brussels Sprouts

Due to brussels sprouts’ need for a long growing season, we recommend planting them with a fall or winter harvest in mind. They do best when allowed to mature during the cool days of fall.

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.)

How to Plant Brussels Sprouts

  • Sow seeds about ½ inch deep.
  • If direct-sowing seeds outdoors, sow seeds about 2 to 3 inches apart. (Seedlings should be thinned to 12 to 24 inches apart when they reach about 6 inches tall.)
  • Plant seedlings 12 to 24 inches apart.
  • Water well at time of sowing/transplanting.

Growing

  • 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.
  • Brussels sprout plants usually reach heights of 2 to 3 feet, so plan accordingly; they may require staking.
  • 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 the sprouts 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. Also, cover plants with 10 to 12 inches of mulch.

Brussels sprout plants in a field

Harvesting

  • 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.

How to Store Brussels Sprouts

  • Do not wash the sprouts before storing them, only right before use.
  • Keep fresh-picked sprouts in a plastic bag for up to 5 days in the refrigerator.
Brussels sprouts on the plant. Photo by audaxl/Getty Images.
Photo by audaxl/Getty Images
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Wit and Wisdom

  • In 2013, a team of scientists and schoolchildren lit an 8-foot-tall Christmas tree in London with the energy from 1,000 brussels sprouts (a total of about 62 volts).

Pests/Diseases

Brussels Sprouts Pests and Diseases

Pest/DiseaseTypeSymptomsControl/Prevention
AphidsInsectMisshapen/yellow leaves; distorted flowers/fruit; sticky “honeydew” (excrement); sooty, black moldGrow companion plants; knock off with water spray; apply insecticidal soap; put banana or orange peels around plants; wipe leaves with a 1 to 2 percent solution of dish soap (no additives) and water every 2 to 3 days for 2 weeks; add native plants to invite beneficial insects
Black rotFungusYellow, V-shape areas on leaf edges that brown and progress toward leaf center; leaves eventually collapse; stem cross sections reveal blackened veinsDestroy infected plants; choose resistant varieties; provide good drainage; remove plant debris; rotate crops
Cabbage loopersInsectLarge, ragged holes in leaves from larval feeding; defoliation; stunted or bored heads; excrementHandpick; add native plants to invite beneficial insects; spray larvae with insecticidal soap or Bt; use row covers; remove plant debris
Cabbage root maggotsInsectWilted/stunted plants; off-color leaves; larvae feeding on rootsUse collars around seedling stems; monitor adults with yellow sticky traps; use row covers; destroy crop residue; till soil in fall; rotate crops
CabbagewormsInsectLeaves have large, ragged holes or are skeletonized; heads bored; dark green excrement; yellowish eggs laid singly on leaf undersidesHandpick; use row covers; add native plants to invite beneficial insects; grow companion plants (especially thyme); spray Bacillus thuringiensis (Bt)
ClubrootFungusWilted/stunted plants; yellow leaves; roots appear swollen/distortedDestroy infected plants; solarize soil; maintain soil pH of around 7.2; disinfect tools; rotate crops
Downy mildewFungusYellow, angular spots on upper leaf surfaces that turn brown; white/purple/gray cottony growth on leaf undersides only; distorted leaves; defoliationRemove plant debris; choose resistant varieties; ensure good air circulation; avoid overhead watering
Flea beetlesInsectNumerous tiny holes in leavesUse row covers; mulch heavily; add native plants to invite beneficial insects
StinkbugsInsectYellow/white blotches on leaves; scarred, dimpled, or distorted fruit/pods; shriveled seeds; eggs, often keg-shape, in clusters on leaf undersidesDestroy crop residue; handpick (bugs emit odor, wear gloves); destroy eggs; spray nymphs with insecticidal soap; use row covers; weed; till soil in fall
White moldFungusPale gray, “water-soaked” areas on stems, leaves, and other plant parts that enlarge and develop white, cottony growth, later with black particles; bleached areas; crowns/sprouts rot; plants wilt/collapseDestroy infected plants; ensure good air circulation; water in morning; weed; destroy crop residue; rotating crops on 5-year or longer cycle may help

Cooking Notes

We prefer roasting sprouts—they have a lovely carmelized flavor!

About The Author

Catherine Boeckmann

Catherine Boeckmann loves nature, stargazing, and gardening so it’s not surprising that she and The Old Farmer’s Almanac found each other. She leads digital content for the Almanac website, and is also a certified master gardener in the state of Indiana. Read More from Catherine Boeckmann