Days to germination: 5 to 10 days
Days to harvest: 60 to 90 days
Light requirements: Full sun
Water requirements: Regular watering
Soil: Well-drained, low nitrogen
Brussels sprouts can be a bit of a challenge to grow, but they will produce a great harvest for your efforts. The plants grown in thick stalks, and produce “sprouts” that look like miniature cabbages along the length of the stalk. They are in the same family as cabbage and broccoli, and the sprouts have that same strong flavor when cooked.
You wouldn’t know it to look at them, but Brussels Sprouts are just packed with vitamin C. They are also good sources of vitamin K and A, folate and fiber.
Starting from Seed
You can seed right into the garden, but starting them indoors for transplanting is the usual routine. Plant your seeds in 3-inch pots about 6 or 7 weeks before your local date for first frost. Seeds should be about 1/4 inch below the surface, in loose potting soil.
Their roots are actually pretty shallow for the size of the plant, so you don’t necessarily need to grow your seedlings in very deep containers
After the last frost date, you can think about planting your seedlings out. The weather will still be quite cool, so you should “harden” your plants before transplanting them. About 4 days before you intend to transplant them, set them in a sunny spot outside during the day. Bring them in for the night. This will acclimatize the plants and help them adjust to the change.
Space the seedlings around 10 inches apart on all sides, and add some extra compost or organic material to the soil while you are planting. Dig the holes for your seedlings a little deeper than necessary, so that the soil level is right up to the bottom leaves once they are in the garden. It will help them get strongly anchored as they grow.
If you prefer, you can seed Brussels sprouts right out in the garden very early in the season. As soon as the ground has thawed and warmed enough to dig, you can put out the seeds even if it means planting several weeks before the final frost date. Because the ground is quite cold, not all seeds will sprout. Make sure to plant more than you need and thin them out later if necessary.
Because Brussels sprouts have such shallow roots, you should never hoe or cultivate around the plants to get rid of weeds. A heavy layer of mulch can help keep the weeds under control instead. This also means they are more dependent on you for watering. Keep them well watered, but don’t soak them.
While the plants are growing, avoid using any nitrogen-rich fertilizer on your Brussels sprouts particularly after the middle of the summer. It can brown the inside of the growing sprouts.
Brussels sprouts do not like hot weather, but unlike cool crops like lettuce, you have to let them grow all through the summer in order to get a full harvest from the plant. If your weather frequently is more than 75 to 80 F, the sprouts may start to open up and change their taste. For plants that got a good early start, you might still get a decent number of sprouts before that happens. You could also try a later planting, though your plants won’t likely reach full maturity before winter hits.
About 4 months after planting, you can pinch out the top of the plant. This will help the upper sprouts to develop a bit faster so you can get as much out of your plant before the winter sets in.
If you’ve harvested the bottom sprouts, the upper one can make the plant oddly top-heavy. Stakes can help them stay upright if necessary.
You can grow Brussels sprouts in large containers (at least 5 gallons each), with one plant per pot. Container gardening has one benefit with Brussels sprouts, that you can move them out of the direct sun during the hottest part of the season which may extend your harvest time.
Like in the garden, only use non-nitrogen fertilizer to keep your sprouts developing properly.
Pests and Diseases
The typical slugs and snails are a frequent problem with Brussels sprouts. A light layer of diatomaceous earth on the soil around the plants will kill any slugs, but its harmless to people and animals. You can buy it at any garden center. Slugs can be picked off in the early morning by hand, if you are so inclined to do so.
Cabbage aphids can be a problem on the leaves, but you can wash them off with regular water when you find them. Just keep checking so they don’t get out of hand. Ladybugs feed on aphids, and you can even buy live ladybugs to release in your garden to help control the pests.
Brussels sprouts can also develop club root, which is a fungus infection that swells up the roots. There is no real treatment for it, but adding lime to the soil can help prevent it if you discover it to be a problem in your garden. If your plants wilt and die for no apparent reason, dig them up and check for bulbous roots. Dispose of the plant immediately and hope it hasn’t spread.
Harvest and Storage
You twist of the mature sprouts when they are firm. Most plants will start to have ripe sprouts 2 to 3 months after you put out your seeds, with the ones at the bottom maturing first.
A healthy plant should yield around a pound of sprouts by the time frost arrives. You don’t need to rush and get the last of them off before your frost date though. They will be fine with a light freeze or two, and your sprouts will be noticeably sweeter for it.
Sprouts that have been picked off the plant will last in the refrigerator for about a week. You can store them longer if you leave them on the plant, and cut the entire stalk off. Hang the stalk somewhere dry, cool and dark. You will be able to pick the remaining sprouts from it for up to 3 more weeks.
They can be frozen and stored that way for several months, provided you blanch them in boiling water for 3 or 4 minutes before freezing.