How to Grow Brussels Sprouts
Brussels sprouts have the unfortunate reputation of being a bad tasting vegetable. However, when freshly harvested and properly prepared, they can be a great addition to your diet and offer many health benefits. Brussels sprouts are cruciferous vegetables rich in antioxidants and a cultivated variety of the cabbage family that also includes cauliflower, broccoli, and kale. They contain ample amounts of vitamin A and C, and are high in fiber.
Brussels sprouts require a long growing season, reaching maturity 80 – 90 days after transplanting and 100 -110 after sowing seeds. Due to their long maturation period, they are an intermediate level plant that is more suited for advanced gardeners who have experience and patience growing crops. Below are a few varieties of Brussels sprouts to help you determine which type to plant.
- Green Gems: ½ inch in diameter, these tiny sprouts derive their name from their emerald color and glowing appearance under sunlight. When cut open, they show a vibrant yellow interior. Their prolific yield and earthly, buttery flavor make them popular for gourmet cooking. This variety is ideal for gardeners who usually do not like brussels sprouts, but want to give them another try.
- Dagan: This variety produces firm, medium sprouts that grow straight and won’t tip over, an occurrence known as lodging. It is a reliable hybrid variety that takes about 100 days to mature and is easy to harvest. These sprouts have a small attachment site, which easily snap off when harvesting.
- Diablo: This plant produces smooth, medium sized sprouts with a delicious sweet taste. It is a slower maturing variety, taking around 110 days, so it is better to plant it during the fall rather than the spring to avoid early heat, which they are averse to.
- Catskill: Catskill is an heirloom variety developed by Arthur White in 1941. It produces extra-large bulbs around 2 inches long on a 24 inch tall stalk. Despite its size, you do not need to worry much about it lodging due to its sturdy, thick stalk. Producing about 10 bulbs per stalk, it is ideal for those that do not want to spend a lot of time harvesting.
Conditions for Growing Brussels Sprouts
When: Brussels sprouts need to be planted 6 – 10 weeks before the first frost of your region. They will sprout when the temperature is between 45 – 80 °F. If you live in zones 9 – 10, plant them in the months of October through December. Gardeners in cooler areas can grow them during late spring or even early summer. If they are planted in hot, dry conditions, they can take on a bitter flavor and become reminiscent of the brussels sprouts many of us hated as children.
Where: Brussels sprouts can be grown in raised garden beds or any controlled garden space. Raised garden beds are recommended for growing cool-weather crops because they allow you to control the soil quality and maintain a consistent temperature during changing seasons and temperature fluctuations. You also don’t have to worry about soil-borne diseases such as clubroot. Brussels sprouts grow best in full sun, so make sure they are in a place that receives at least six hours of sunlight.
The ideal soil is loose and well-draining, with a pH of 6.5 – 7. Like all cabbage family plants, they require large amounts of nitrogen to grow well, so make sure your soil has the appropriate amount. Too much nitrogen will produce fewer and smaller plants; this delicate balance can be difficult to maintain and is another reason this is a more intermediate plant to grow.
Avoid planting related vegetables in the same spot for three years. In addition, Brussels sprouts should not be planted together with heavy feeders such as tomatoes and other nightshades, as they will compete for nutrients. To ensure adequate nutrients, mix your soil with several inches of compost and other organic matter before planting. If you have planted beans or peas before, you can follow with brussels sprouts since legumes enrich the soil with nitrogen.
How: If you want transplants, you can plant seedlings indoors in small containers 3 – 4 weeks before you plan to transplant them outside. When plants reach 5 – 7 inches, they are ready to be transplanted. To avoid transplant shock, pick a shady, cloudy day. If you plant directly into a bed or the ground, space seedlings a few inches apart, but be sure to thin them once they are about 6 inches tall. Transplants should be spaced about 12 – 24 inches apart to start with. Plant them in in-ground rows or raised beds around ¼ to ½ inches deep. If planting in a raised bed, plant the transplants in a zigzag pattern to give each transplant space to grow and still utilize the space. Before transplanting, water the garden bed and the plants to ensure a cool environment. Keep in mind that they can grow to be quite large, so make sure to give them ample space. You should absolutely mulch the area as well to retain moisture and keep the soil temperature cool. Watch Farmer Jim from Texas Eco Farms demonstrate this process: click here.
Care: If you planted the seeds directly, apply a nitrogen rich product to your plants just after you have thinned them. Otherwise, repeat this process every four weeks, or at least two times during the growing season. Since brussels sprouts have shallow roots, they may require staking, so just keep an eye on some of the larger plants for signs of instability. Remove unwanted plants by hand to avoid damaging the root system. Regularly water your plants with 1 – 1.5 inches of water per week. Gently remove any yellow leaves to prevent the chance of infection.
Brussels sprouts require more boron than other plants. Signs of boron deficiency include small plants or hollow stems, and can be confirmed by a soil test. To remedy this, mix 1 tablespoon of Borax with a gallon of water and evenly water your plants with this solution.
Like with all cabbage plants, Brussels sprouts are prone to cabbage worms. If you spot those pests, remove them by hand and drop them in a bucket of soapy water. Alternatively, you can cover crops with garden fabric or mesh to serve as a barrier. Companion plants such as garlic, marigolds, and mint can help deter pests like cabbage worms.
They are also susceptible to a fungal infection known as club root, which attacks the root structure of the plant, leading to gnarled roots and stunted plant growth. To prevent clubroot, make sure the transplants are healthy and disease free before planting, and compress the soil to eliminate air gaps that can lead to disease. It is important to keep the area free of clubroot, as treatment methods are expensive, difficult, and not very effective. You have more flexibility in a raised bed, but it is still not ideal. If the area is infected, raise the soil pH to 7.2 by adding dolomite lime to help fight it off.
How to Harvest Brussels Sprouts
Most brussels sprouts can be harvested after about 80 days after planting, with the precise time depending on the variety. Snip off the sprouts when they are 1 – 2 inches in diameter by twisting them from the stem, starting from the bottom of the plant. When you are removing the sprouts, make sure to also remove any yellow leaves that appear. You should harvest once the leaves start turning yellow to ensure tenderness and bold flavor. Store brussels sprouts in a plastic bag in a refrigerator, where they can last up to a week. Instead of washing immediately after harvesting, wash them when you are ready to prepare to preserve them even better in storage. Trust me, it has helped my cooking tremendously! If you have picked them attached to the stem, store them with a wet paper towel in the bag as well to keep the stalk hydrated.
Brussels sprouts are biennial, which means they will grow for two years before requiring replanting. They can survive some frost and snow. Frost can actually be beneficial to their flavor by triggering energy for sugar production. For improved flavor, harvest them just after a frost if possible.
If you are giving brussels sprouts another shot after years of hating on them, then I recommend making some honey glazed brussels sprouts. They are so delicious that even the pickiest of eaters may be surprised!