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How to Plant and Grow Brussels Sprouts

unharvested brussels sprouts on the stalk
Image Credit:
Pixabay
Botanical Name
Brassica oleracea
Grown as
USDA Zones
Toxicity
Sun Exposure
Water Needs
Height
Spread
Soil pH
Special Features
Resilience
Plant Type
Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

Brussels sprouts: those little green globes that get a bad rap—until you grow your own! When grown right, these cool-season veggies are sweet, tender, and packed with nutrition, and actually improve in flavor after a light frost. Whether you’re new to growing or ready to level up your fall harvesting game, here’s everything you need to know about cultivating Brussels sprouts and how to harvest the absolute best tasting sprouts around.

Brussels sprouts close up.

Planting

When to Plant Brussels Sprouts

Brussels sprouts are a slow-growing, long-season crop that grows best in cool weather and can turn bitter when temperstartures get too high.

Most varieties take between 80 to 100 days to reach a harvestable size when grown from transplants, which is the recommended growing method. I get the best results by planting nursery-grown transplants outdoors about 90 to 110 days before the first fall frost. 

If you’re a reasonably savvy gardener, you can also start plants indoors from seed by sowing the seeds about 6 to 8 weeks before your last spring frost date. However, this is a trickier process!

Where to Plant Brussels Sprouts

Choose a planting site that gets full sun or about 8 to 10 hours of direct light per day. Raised beds are especially good for cool-season vegetables — particularly in the spring and fall when temperatures are irregular.

Brussels sprouts crave lots of nutrients, so be sure to work several inches of aged manure or compost into the soil before planting.

How to Plant Brussels Sprouts

To plant, work compost into the soil and then plant transplants at the same depth they were growing in their nursery pots. Firm the soil around the base of the transplants, space multiple plants 18 to 24-inches apart in rows located about 24 to 30-inches from each other, and water well. Adding mulch around the base of your plants will keep weeds down.

If you’re growing sprouts from seed, plant 2 seeds 1/4-inch deep per pot or planting cell and thin the weakest seedling out with fingernail scissors once true leaves form. Remember to harden off indoor plants before transitioning them outside.

Growing

Watering

Inconsistent moisture can lead to subpar sprout development. To avoid this, provide Brussels sprouts with about 1 to 1 1/2-inches of water per week, and add mulch around the base of your plants too.

Fertilizing

Brussels sprouts are heavy feeding plants. For bigger sprouts, sidedress plants 2 to 4 weeks after planting or when the plants are 12-inches high using an organic, high-nitrogen fertilizer. Reapply the fertilizer every 3 to 4 weeks after that.

Pruning or Maintenance

As they grow, Brussels sprout stems can easily reach over 2 to 3-feet tall and may require staking. Removing the yellowing leaves at the bottom of the plant boosts light levels around the plant’s stalk and helps increase sprout size. When working around your sprouts, take care not to disturb their roots as they’re shallow and easily damaged.

Seasonal Care

Like other brassicas, Brussels sprouts are prone to pests like cabbage loppers — especially right after planting. Protecting young plants with row covers can help. You can also try out organic pest control measures like BT thuricide.

  • If you want to encourage sprouts to mature faster, cut off the top leaves 3 to 4 weeks before harvest.
  • If you intend to harvest sprouts into winter, leave the plant’s top leaves intact as they provide protection from snow. Then, cover plants with 10 to 12-inches of mulch.

Brussels sprout plants in a field

Harvesting

When to Harvest

Brussels sprouts are typically harvested from fall to early winter and taste sweeter after a light kiss of frost. Sprouts mature from the bottom of the stalk upwards and are ready to pick when they’re about 1-inch in diameter. Ripe sprouts should be firm, green, and have tightly closed leaves, while overripe sprouts will look yellow and open.

How to Harvest

Individual sprouts can be snapped off the plant’s stems with your fingers or cut free with a sharp knife. You can also pull the entire stalk of the plant up, roots and all.

Storage

Stalks of harvested Brussels sprouts can be stored in a root cellar or basement for about a month once you trim the roots free. Individual sprouts last about 1 to 2 weeks in the fridge when stored in a loose plastic bag, but they’ll keep even longer if you blanch and freeze them. For longer storage, don’t wash Brussels sprouts until just before use.

 

Brussels sprouts on the plant. Photo by audaxl/Getty Images.
Photo by audaxl/Getty Images

Pests and Problems

Common Problems

  • Undersized sprouts can be caused by heat stressed or low nutrient soil. It may also result from harvesting sprouts too early!
  • Bitter flavor can ruin sprouts that are planted too late in spring and subjected to hot weather. That’s why it’s best to plant Brussels sprouts for cool weather harvesting.

Common Pests

  • Aphid infestations can leave Brussels sprout leaves misshapen and yellow and cause distorted sprout growth. Growing companion plants can help to naturally deter these pests, while active infestations can be dispelled with your garden hose or treated with an organic insecticidal soap spray.
  • Cabbage loopers are small, green caterpillars that bore ragged holes through Brussels sprouts and their leaves. Using row covers or BT thuricide are the most reliable ways to prevent looper issues, but you can also deter loopers with companion planting and adding feeders near your garden to attract visiting birds.

Plant Diseases

  • Black rot is a fungal issue that causes plant leaves to turn yellow and develop v-shaped brown lesions that eventually collapse. Infected plants should be dstroyed, while future issues can be prevented by growing resistant cultivars and rotating crops seasonally.
  • Clubroot is also caused by a fungus and produces wilted and stunted plants, yellowing leaves, and distorted root growth. Keeping soil pH levels slightly alkaline can help to minimize risks of this disease; however, if clubroot has already made its way into your garden, you’ll want to destroy infected plants and potentially solarize the soil too.

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 or a total of about 62 volts.
  • Brussels sprouts were first cultivated in Brussels, Belgium in the 16th century — which is how these veggies got their name!
  • Like closely related cabbages, broccoli, kale, and cauliflower, Brussels sprouts are a cultivar of the wild cabbage, Brassica oleracea, which was carefully cultivated over generations to produce a wide variety of our favorite cool season vegetables. 

About The Author

Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann is the Executive Digital Editor of Almanac.com, the digital home of The Old Farmer’s Almanac. She leads digital editorial strategy and publishing across a wide range of Almanac sub...

Read more from Catherine Boeckmann