Brussels sprouts are among the many "cole crops" grown in the home vegetable garden. Cole crops is a general term used to describe several vegetables in the mustard family, including broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, and kohlrabi. All cole crops are cultivated varieties of the species Brassica oleracea. Cole crops are cool-season vegetables that grow best at temperatures between 60° and 70°F and can withstand light frosts without injury.
Suggested Cultivars | Planting | Care | Potential Problems | Harvest & Storage | More Information
Suggested Cultivars for Iowa
- Diablo – tall plants; late maturing cultivar
- Franklin – early maturing cultivar
- Gustus – dark green sprouts
Hestia – medium-size sprouts; plants are shorter than other cultivars - Jade Cross – large, dark green sprouts
Planting
Brussels sprouts are best started by seed indoors, and transplants are planted in the garden in late spring for a fall harvest. Unlike other cole crops, there is not enough time to get both a spring and fall crop in one growing season. They perform best as a fall crop as they will come into maturity when temperatures are cool.
Schedule
Plant Brussels sprouts in the garden in early to mid-May in central Iowa. (Gardeners in southern Iowa can plant about one week earlier, while those in northern counties should wait one week later.) Sow seeds indoors 4 to 5 weeks before planting outdoors or purchase young, stocky transplants at a greenhouse or garden center. Harden or acclimate the transplants outdoors for several days before planting. Initially place plants in a shady, protected location and then gradually expose them to longer periods of sunlight. Depending on the cultivar, plants are ready to harvest 85-110 days after transplanting. This is typically late September to early November.
Site
Cole crops, like Brussels sprouts, perform best in fertile, moist, well-drained soils. An ideal soil pH is between 6 and 7. The planting site should also receive at least 6 hours of direct sun each day. To avoid disease problems, rotate the placement of cole crops in the garden. If possible, plant cole crops in a given area only once every 3 or 4 years.
Spacing
When planting cole crops in the garden, space plants 18 to 24 inches apart within the row. Rows should be approximately 24 to 30 inches apart.
Care
Watering
Most cole crops, such as Brussels sprouts, have shallow root systems and require weekly irrigation if rainfall doesn’t provide one inch of water per week. If possible use soaker hoses or drip irrigation systems to prevent wetting the foliage. Watering only the plant's root zone can also reduce the number of weeds that may germinate. Learn more about watering in this article: Watering Tips for the Garden, Lawn, and Landscape.
Fertilizing
If a soil test has not been done, apply 1-2 pounds of all-purpose garden fertilizer, such as 10-10-10, per 100 square feet, and incorporate it into the top 4-6 inches of soil before planting. Conduct a soil test to get more precise fertilizer recommendations based on your garden's fertility.
About 3-4 weeks after planting, broadcast a small amount of an all-purpose garden fertilizer in a band along one side of each row.
Mulching & Weeding
Control weeds to prevent competition for water, nutrients, and light. Shallow cultivation, hand pulling, and mulching are the best weed control options.
A 2-3 inch layer of mulch, such as straw, dry grass clippings, or shredded leaves, helps control weeds and conserves soil moisture. Learn more about weed control in this vegetable garden in this article: Weed Control in the Vegetable Garden.
Topping or Pinching
When the diameter of the lower sprouts is about 1/2 to 3/4 inches, remove the top growing point of the plant. This should be done less than 60 days before harvest (mid-September). This will promote the growth of the sprouts on the upper portion of the stalk and provide more uniform development, allowing you to harvest all of the sprouts on the plant at the same time.
Potential Problems
Cabbageworms
Cabbageworms are greenish caterpillars that eat large, irregular holes in the foliage of most cole crops. Treat when caterpillars are first noticed with products containing Bacillus thuringiensis (Bt). When consumed by cabbageworms, this bacterium produces toxins which destroy the insects. Synthetic and other organic pesticides also can be used.
Flea Beetles
Flea beetles eat small, round holes in the foliage, resulting in “shothole” damage. Adults are tiny, shiny, black beetles. They possess large hind legs that enable them to jump.
Minor flea beetle damage will have little effect on crop yields. If significant damage begins to appear, treat plants with an insecticide. As always, carefully read and follow label directions when using pesticides.
Aphids
Aphids can sometimes be seen among the small heads. Often, control can be done through a combination of natural enemies and a forceful spray of water.
Harvest & Storage
Brussels sprouts are typically ready to harvest 85-110 days after planting transplants in the garden, depending on the cultivar.
One or more light frosts improve the flavor of Brussels sprouts. Harvest individual sprouts or buds from the base of the plant as they become solid. Buds should be 1 to 1½ inches in diameter and tender and green. Remove buds higher up on the plant as they become firm. Do not strip the lower leaves from the plant, as they are necessary for further growth.
If plants were topped, the stalk should have more uniform development from top to bottom, allowing you to harvest the entire stalk at once when all of the buds are 1 to 1-1/2 inches in diameter.
Sprouts may be placed in a perforated plastic bag and stored in the refrigerator for up to 3 to 5 weeks.
With good management practices, the average yield per 10-foot row of Brussels sprouts is 7-10 pounds.
More Information
- Cole Crops (publication)
- Growing Broccoli in the Home Garden
- Growing Cauliflower in the Home Garden
- Growing Cabbage in the Home Garden
- Growing Kohlrabi in the Home Garden
- Vegetable Harvest Guide
- Vegetable Planting and Harvesting Times
- Planting and Harvesting Times for Garden Vegetables (publication)
- Fall Planting of Vegetables
- Crop Rotation in the Vegetable Garden
- Weed Control in the Vegetable Garden