Growing Brussels Sprout: Everything You Need To Know

What family are Brussels Sprouts related to and what are their appearance?

Brussels Sprouts belong to the Brassica oleracea (Cole crop) family, which includes cauliflower, broccoli, collards, kale, cabbage and kohlrabi. Brussels sprouts form from buds on the trunk of the plant which grow between the stems and large green leaves.

When to plant Brussels Sprouts:

The best time to plant your Brussels Sprouts is when it is cool. Ideal growing temperatures are between 45 degrees and 75 degrees Fahrenheit. They can grow in nearly any part of the country, but require cooler weather. Ideally, they should be planted in early Spring or even mid to late summer for a crop that will be ready in the fall. They have small heads whose ideal growing condition is cool and even a cool that produces a light frost. Brussels Sprouts that are grown in weather that is hot and/or dry will be bitter and flimsy.

How to plant/Conditions needed for growth:

You'll need to be patient when growing Brussels sprouts as they are a slow-growing vegetable. Like most vegetables, Brussels sprouts need a minimum of 6 hours of sunlight every day in order to grow. If it's possible for them to get more, great, if not 6 hours is the minimum goal for the best crop. Try to plant them in soil with plenty of organic matter; they flourish best in soil that is moist and drained with a soil pH that is on the high end for vegetables. For optimum growth, the ideal soil pH should be around 6.8, but you should be ok anywhere between 6.5 and 7.5. You can purchase a soil testing kit at any full-service garden center.

Seedlings should be planted a 1/4 inch to a 1/2 inch deep. Apply lime and fertilizer to your soil according to the results of the soil test. If you did not do a soil test, be sure to add nitrogen-rich amendments to your soil. These include composted manure, blood meal or cottonseed meal. As an alternative, you could also use a timed-release vegetable fertilizer, but be sure to work it thoroughly into the soil before planting. Brussels sprouts also require more of the plant nutrient boron than other vegetables. Without boron, which is used in small quantities by all plants, the Brussels sprouts will end up developing small buds and hollow stems. If you have an existing crop planted that is showing these conditions, you can still add boron to the soil. To do this, use one tablespoon of borax in 5 quarts of water and then sprinkle it evenly over 50 square feet of bed space. If you did not add boron when you started and your plants are not showing these signs, you should leave them alone.

When planting, leave about 18 to 24 inches apart in a row or bed as they grow quite large. If you are going to plant them in rows, you allow space of at least 30 inches apart from each other to allow yourself room to walk. Don't get seedlings until you are ready to plant them as they should not be left out or they will dry out. If you purchased seedlings and are not ready to plant, they can be kept in the refrigerator for 3-4 weeks and can also be frozen for around 4 months after blanching. After you plant the seedlings, you should water them well to encourage healthy growth. You should not attempt to transplant Brussels sprouts seeds as they may never fully mature.

Size of Brussels Sprouts when grown/length of time to grow

If given enough space when planted, a healthy Brussels sprout plant will grow up to 2 1/2 feet tall. It will take approximately 100-110 days for your plants to mature after planting.

Care during growth:

In order to attempt to get all of the sprouts on a plant to come to harvest at the same time, you should pinch off the top terminal bud when the plant is around 15 to 20 inches tall or about 4 weeks before harvest time. Lower leaves can be removed from the sides of the stalks as the sprouts develop while leaving the top leaves intact. You should keep them well-watered by starting at the base of the plant. As the crop nears maturity, the amount of watering should decrease.

Common pests/diseases:

Brussels sprouts can be attacked by cutworms, cabbage loopers and imported cabbage worms. In order to control these pests, hand pick them off the plant or spray with bacillus thuringiensis.

Brussels sprouts are prone to diseases such as club root, downy mildew or yellows. To try and prevent these diseases, you can plant disease-resistant varieties, rotate your crops every year, and keep the garden clean. If you do end up with a diseased plant, remove it  immediately to prevent further spread of disease to the other plants.

Harvest time:

If you have pinched the growing tip of the plant 4 weeks prior to harvest, all of your Brussels sprouts should come to harvest at the same time. Your Brussels sprouts will taste best when the buds are small and tight with a diameter of around 1 to 1½ inches. If the tips have not been pinched, the sprouts mature from the bottom of the stem upwards . In addition to the Brussels sprouts themselves, the tender leaves can also be eaten as greens or cooked like collards. The cooler the growing condition, the sweeter the buds will be.

For more information or any other questions regarding planting Brussels sprouts or other plant, or any other gardening questions, contact us today!