How surprised were you as an adult the first time you tried a Brussels Sprout again and realized you actually liked it? Sweet and mild, they are vitamin-packed and so versatile they can be eaten raw in a slaw, steamed, roasted, and even fried. Growing your own is so satisfying, and the plants are really cool looking too!
The best way to grow Brussels Sprouts depends to some extent, on where you live. These plants need a long growing season and thrive in cool temperatures.
In most areas, sow seeds indoors in spring for fall crops. Move seedling transplants to the garden in mid-spring to early summer 60-80 days before the first fall frost date.
In areas with cool, long summers, sow seeds in the garden in midsummer for a fall crop.
In the South (zones 8-11), start transplants in late summer or sow seeds directly outdoors in fall, and grow the plants as a winter to spring crop.
Wherever you grow these long-season plants, be sure to provide them with rich, deeply prepped soil. Mulch and consistent watering will help them survive hot weather. Both are especially important when temps exceed 80 degrees.
Planting and Aftercare:
For spring planting, count back about 100-120 days from last frost-free date to determine when to start your seeds. Spring plantings will require you to start your seeds early, and set them out under cover to ensure enough cool days to form florets. Beginners may do best starting with fall plantings. For fall planting, count back 90-110 days from the first fall frost to determine your sowing date. Fall plantings can be started inside and planted out at no more than 8 weeks old, or direct sown in the garden under a shade cloth.
Sow three seeds per pot, ¼” deep and water well. When seedlings have four leaves, thin to one per pot and keep your grow lights close to the tops of your plants, moving them up as they grow. When your plants are 4-8 weeks old, harden them off to the outside weather in preparation for planting in your garden.
Brassicas like Brussels Sprouts benefit from a long, slow, hardening off period. Beginning about four weeks before you would like to plant outside in your garden beds, start setting your plants out in a protected spot during the day and bringing them in at night. Start with just an hour on the first day, gradually increasing until the plant babies spend all day outside. During the last week, the week before you are to transplant outside, keep your plants outside at night too. Make sure to keep them under frost cover, even an old sheet will do, as your plants are especially vulnerable when still in their small starter pots.
In your chosen planting area, spread 2-3” of compost and fork your soil to aerate it. Plant your seedlings out at 18-24” apart. Covering plants with floating row covers will greatly help with deterring insects during your plants vulnerable young stage.
Feed monthly with your favorite natural, balanced fertilizer during the active growing season of summer or early fall depending on your planting. Water weekly as needed.
When you are ready to start harvesting, twist sprouts from the stalk starting at the bottom. Sprouts will continue to mature from the bottom, up. Frost improves the flavor greatly, so I like to wait until after the first frost hits to begin harvesting.
Tips for Success:
Do not pick Brussels Sprout leaves in the fall, those leaves will protect the sprouts from freezing.
Choose a planting site that gets at least 8 hours of direct sun per day, with rich, well-drained soil. A few inches of mulch will help keep the soil cool for summer temperature regulation.
You can harvest Sprouts as you need them from the bottom up, or pull the whole plant at once, cutting off the leave and roots and storing them at 40 degrees F. To encourage all sprouts to mature at once, pinch top growing tip when the lowest sprouts are ½ - ¾” wide.
Trouble to Watch For:
Diamondback moths flutter around Brussels Sprout plants and lay eggs that hatch into slow-moving, green-yellow, 1/3” long caterpillars. These larvae chew small, ragged holes in leaves and growing leaf tips.
Cabbage Loopers, also known simply as Cabbage Worms, are thin, green caterpillars that chew large, ragged holes in leaves. Cover plants with floating row covers, handpick caterpillars, or dust plants with Bt to control all kinds of worms on your brassicas .As with any pesticide, even the organic ones, make sure to follow the directions on the packaging!
Cutworms are fat, green, 1 ½” long, fantastically camouflaged, pests. They chew on the area at the top of the cabbage’s roots and on leaves. Place a collar (a cat food can with both ends removed works well) around seedlings to protect them. Remove the collar once the plants are established.
Handpicking is an option too, and good news, your chickens will LOVE the worms you picked for them! Or you can just squish them.
Growing Zone and Special Conditions:
Brussels Sprouts can be grown in all areas of the United States. Their long time to maturity and sensitivity to nutrient imbalances have given them a reputation for being difficult. With well worked, fertile soil, regular feedings and well-timed plantings, you can grow the most delicious Sprouts you’ve ever had! Brussels Sprouts are biennial, meaning they won’t send out a flower until second year of growth, often triggered into flowering by the end of a winter season.
In areas with mild winters, it is possible to over-winter Brussels Sprouts in the garden under frost protection.
Written by Sow True Seed's Education Director, Angie Lavezzo.