Although Brussel sprouts date back to ancient Rome, they're named for the city of Brussels, Belgium, where they have been enjoyed since the 14th century. Part of the cabbage family, Brussels sprouts can be grown in just about any home vegetable garden as long as you have patience—they are slow-growing plants that require a long growing season.
If you seen Brussels sprouts only in the grocery store, you will delight in the striking appearance of their plant form: The numerous mini cabbage heads form along thick, 30-inch-tall stalks, along with bold, jutting stems and broad, cabbage-like leaves. The leaves are also edible and can be prepared like other hardy greens.
Like other vegetables in the Brassicaceae family, Brussels sprouts taste best after they have been subjected to cool weather. Usually, that means harvesting after a light frost or a snow. In cooler climates, they are best planted in early summer for a fall harvest. In warmer climates, they should be planted in late summer for a late fall or winter harvest.
|Botanical Name||Brassica oleracea (Gemmifera group)|
|Common Name||Brussels sprouts|
|Plant Type||Annual vegetable|
|Mature Size||30 in. tall, 8 to 12 in. wide|
|Sun Exposure||Full sun|
|Soil pH||Neutral (6.5 to 7)|
|Hardiness Zones||2 to 9|
How to Plant Brussels Sprouts
Brussels sprouts require a long growing season of 80 days or more, and they improve in flavor after being subjected to a light frost. In colder climates, you can start brussels sprouts seeds indoors around early May, and transplant the seedlings to the garden in mid-June, or about four months before the first fall frost. Plant only after the last spring frost. Be sure to allow the full time outdoors for required days to harvest. In warmer climates, fall planting is preferred. You should be able to direct seed in mid-summer for a late fall or early winter harvest.
Brussels Sprouts Care
The plants will grow and sprout best in full sun and need at least 6 hours of sun daily. Too much shade will slow the sprouts' maturity.
Brussels sprouts like a slightly acidic to neutral soil that is fertile, well-drained and moist, with plenty of organic matter. The soil pH should be between 6.5 and 7. A good amount of organic matter will help maintain the moisture they need for their intense growth.
Brussels sprouts like the soil around them to be firm, but not compacted. Pat it down lightly.
Keep the sprouts' soil moist but not soaked, giving it between 1 and 1.5 inches of water per week.
Temperature and Humidity
Brussels sprouts prefer temperatures between 45 and 75 degrees Fahrenheit. They'll tolerate a couple of days below freezing, and even improve their flavor with a bit of light frost. This is not a warm-weather crop—sprouts that mature during hot or dry weather will be bitter and flimsy.
Fertilize Brussels sprout plants twice a season with a nitrogen fertilizer—once when the plants are about 12 inches high and again four weeks later.
Varieties of Brussels Sprouts
- 'Bubbles' F1 (85 to 90 days to maturity): This variety tolerates heat and drought, and grows 2-inch sprouts that are resistant to powdery mildew and rust.
- 'Jade Cross' F1 and "Jade Cross E" F1 (90 days): Jade Cross was a 1959 All-America Selections Winner. Both are compact plants that are good for windy locations. The sprouts are slightly larger on 'Jade Cross E.' Good disease-resistance.
- 'Long Island Improved' OP (90 days): This variety is another small but high-yield plant that stands up to wind and tolerates freezing.
- 'Oliver' F1 (85 days): An early producer, the 1-inch sprouts are easy to pick and the compact plant is disease-resistant.
- 'Royal Marvel' F1 (85 days): ''Royal Marvel' is an early and productive plant that is resistant to bottom rot and tip burn.
- 'Rubine' (85 to 95 days): These heirloom purple plants are late-maturing and lower-yield than green varieties but have good flavor.
Brussels sprouts take about three to four months from transplant before you can begin harvesting. They grow tall first and don't start producing sprouts until they reach almost full height. Each sprout grows in the leaf axil or joint. They begin maturing from the bottom of the plant upward. Start harvesting when the lower sprouts reach the size of large marbles. Pick the sprouts before they get too large and start cracking and turning bitter.
Pulling off the sprouts is easier if you remove the leaf below the sprout first, then twist and pull the sprout. Some people prefer to cut, rather than pull the sprouts. Each plant yields approximately a quart of sprouts total.
After harvesting, a second crop of Brussels sprouts may begin to grow at the base of the stem. These will not be as tight as the first buds, but they are still edible. The leafy tops are also edible and can be cooked as greens. Cutting the tops is a good way to speed up the development of the remaining sprouts, at the end of the season.
To extend your Brussels sprouts harvest in cold seasons, mulch plants with straw and/or cover with a row cover for protection. Whole plants can be pulled, potted and stored in a root cellar. Bare root plants stored in a cool cellar will give you an additional two to three weeks of harvest.
How to Grow Brussels Sprouts From Seed
If you live in an area with cold winters, start your seeds indoors about two to three weeks before the last spring frost. For areas with mild winters, start the seeds outdoors in the early to mid-summer for a mid-fall or early winter harvest. If you live in a region with warm winters—where temperatures are rarely below freezing—start seeds outdoors in the late summer for a mid- to late-winter harvest. Cover the seeds with 1/4 to 1/2 inch of soil, and keep the soil moist.
Space seeds for outdoor plants about 2 feet apart with 3 feet between rows, or stagger plants 2 feet apart in each direction, for a grid layout. When the plants are about 6 inches tall, thin them as needed to a spacing of 12 to 24 inches.
Transplant indoor seedlings to the garden when they are about 3 inches tall. It is very important that you do not allow the seedlings to become root bound or the plants will remain stunted when transplanted.
Common Pests and Diseases
Brussels sprouts are prone to the same problems as cabbage and broccoli. The most common pests are cabbage looper, imported cabbage worm, cabbage root maggot, aphids, and Harlequin bug. Because this is a late-season crop, you have time to monitor for problems before the sprouts start forming.
Diseases include blackleg, black rot, and clubroot. Disease control is best achieved by rotating the crop each year. Clubroot is diminished when you raise the soil pH to about 7.0.