A polarizing vegetable, you either love or hate Brussel sprouts. However, fresh from the garden, they are sure to be able to turn even the most staunch Brussel-hater into a major cruciferous fan. Growing Brussel sprouts from seed doesn’t have to be daunting, and it can open your eyes to all the varieties available to grow in your backyard. Follow along to learn how to grow Brussel sprouts from seed, care tips throughout the growing season, and what problems you might encounter, along with their solutions.
What Are Brussel Sprouts Growing Stages?
Brussel sprouts rebel against the typical seed-seedling-flowering-harvest guide that most plants subscribe to, though they don’t necessarily stray too far. Brussel sprouts growing stages are straightforward but with a bit of a twist.
- Planting. Starting from seed, you will need to sow the seeds about three months before the first frost date if you’re starting your seeds outdoors. To start your sprouts in containers, this can be done indoors, with transplanting outdoors occurring in the early to late fall months.
- Early Growth. Taking care of the early growth sets you up for success when the stalks reach maturity. Fertilizing, mulching, and thinning out seedlings are all part of the early growth care checklist to ensure a bountiful and healthy harvest.
- Sprouting. The sprout formation occurs about 50 days after planting. During this stage, you will want to remove the apical (top) buds to encourage faster growth.
- Harvesting. The best part of this growing endeavor is harvesting. Depending on the variety, your sprouts are ready to harvest when they reach about 1-2 inches (3-5cm) in diameter; this is likely at around the 100-day mark. Freezing temperatures can bring out more flavor in a crop, but they will no longer grow after they’ve experienced a freeze.
How to Plant Brussel Sprout Seeds
How to plant Brussel sprout seeds does not differ too much from planting any other seeds. Some varieties with longer growing periods may need some planning, but overall, planting Brussel sprouts seeds, pruning Brussel sprouts, and harvesting the sprouts is all very similar to other crops that can be grown in the garden.
- Start your seeds outside 6-10 weeks before the first frost or 4 weeks before the last frost to start indoors. Plant the 2-3 seeds at about ½ inch (1cm) depth in your potting medium. Give them gentle water or mist after lightly covering up with soil.
- Temperatures between 70-75ºF (21-24˚C) are optimal for germination. Room temperatures indoors should be sufficient without using a heating pad to germinate, as these are cool-weather crops.
- Seedlings will emerge around 5-7 days after planting. After a couple of sets of true leaves have grown on your plant, seedlings can be transplanted to larger pots with fertile soil to continue their early growth. If you are starting your seeds outdoors, there is no need to transplant them.
- If transplanting seedlings outdoors, ensure you have either hardened off your young plants or relocate them outside on a cloudy, mild day to reduce transplant shock.
- Plant the seedlings about 1.5-2 feet (0.5-0.6m) apart to allow for airflow and room to reach full maturity. Choose an area in your garden that can get at least 6 hours of sunlight for optimal growth. Adding mulch or organic compost to your seedlings can help retain moisture and aid in growth, respectively. Prune any bottom sprouts or yellowing sprouts as they grow to keep them off the ground.
Keep the sprouts watered and fertilized, especially through the early growth stage, and your hard work and efforts will pay off early to mid-winter when you have a bountiful brussel sprout harvest. Pruning will occur while your plant is maturing, so remove any lateral branches that form to help re-focus your plant’s energy on growing the sprouts.
When to Plant Brussel Sprouts
When to plant Brussel sprouts depends on the climate and variety used. Generally, these are cold-weather plants that can be grown in colder weather as long as the full sun is available. The information on seed packets can be used to work backward to a starting date to start the seedlings. They can be started in the ground where you intend to grow them, or go ahead and sow the sprouts in pots to be later transplanted outdoors, especially if you have a variety that takes longer to grow.
How Long Do Brussel Sprouts Take to Grow?
The time it takes to grow Brussel sprouts from seed depends on the variety, though generally speaking, from seedling to harvest, it can take between 90-120 days. Brussel sprouts enjoy growing in cold weather and often benefit from a frost or freeze right before harvest to bring out a sweeter, more developed flavor.
Brussel Sprouts Varieties
Part of growing Brussel sprouts seeds is the perk of having many options to choose from. Brussel sprout varieties can have a different time to harvest but generally require similar care across the board.
- Churchill. Grows quickly and yields about 14 ounces (0,4kg) of sprouts per plant in about 90 days. This variety is great for those wanting quantity, quality, and speed, though this variety is more susceptible to disease, so take care to prune the lateral branches that form to keep air flowing around the plant.
- Diablo. At two feet (0.6m) tall, the Diablo variety of Brussel sprouts grow uniformly on a two-foot-tall “tree” with medium-sized sprouts. These take on the longer end to mature, about 110 days until harvest, but it is worth the extra time investment for their tasty, nutty flavor.
- Green Gems. Smaller sprouts that still pack a punch are grown in a short 85 days until harvest. This variety may need some help standing upright if the wind is a common issue in your area.
- Hestia. Giving the best of both worlds, this variety matures in about 95 days, has uniform growth, and is actually award-winning! They hold the All-American Selections award for vegetables. The best part is they don’t even need the freeze or frost to bring out their buttery, sweet flavor.
- Mighty. The Mighty Brussel sprout is exactly as its name would suggest – small but mighty in flavor. Growing around 1 inch (3cm) in diameter, these are perfect for roasting whole. Additionally, they are resistant to mildew and leaf spot.
- Redarling. A colorful take on the traditional sprout, Redarling is a purple variety with 1.5 inch (4cm) diameter sprouts. These sprouts hold their color when they’re heated, so it’s just as beautiful on the plate as it is in the garden. This variety is a slow grower, so planning is in order because they’re not ready to harvest until about 140 days.
Brussel Sprouts Companion Plants – Who Are They?
Companion plants are additional herbage that can be grown in conjunction with other crops that will mutually benefit each other either by enhancing growth or deterring pests, and sometimes both. Brussel sprouts companion plants can be other food crops, flowers, or even a “trap” crop.
For Brussel sprouts, which can be plagued by bugs such as aphids and cabbage moths, planting companions such as basil, garlic, and mustard. These strong scents repel certain pests, and the mustard is more of a decoy for pests that would normally eat the sprouts. Other good companions are marigold, nasturtiums, and mint, though mint can take over an area and is best left in containers.
Brussel Sprouts Growing Problems & Troubleshooting
When considering how to grow Brussel sprouts from seed, you also have to consider what issues you might run into along the way. Keeping a tidy area free of scraps and a well-maintained garden and monitoring your plants are a good way to stay in tune with the happenings in the garden, but is not a fool-proof way to ensure a bountiful and problem-free harvest.
The Brussel sprout plant stages most likely to cause grief are the plants in the early growth stage and the harvest stage, as these are when the plant seems to most appealing to pests and disease. Here are the most common Brussel sprouts growing problems and what steps you can take to mitigate them.
- Young plants not growing. An integral part of the early growth phases is fertilizing with a high phosphorus fertilizer diluted to ½ strength. This provides your plant with a strong root system to anchor itself in the ground.
- Tunnels in the sprouts. This is the work of a cabbage root fly. To prevent these flies, you might have to use companion planting or invest in caging off your plants.
- Leaf spot. Alternaria leaf spot causes little black dots to your Brussel, which eventually will spread and cover the whole plant. Some varieties, such as the Mighty variety, are naturally resistant to this, though you can peel off the affected leaves or spray with a fungicide to get rid of Alternaria.
- Black Rot. Much more deadly, this bacteria can take a whole plant out in no time. To prevent this, early treatment with copper fungicide is needed, as once it spreads, there is no cure.
How long do Brussel sprouts last?
It depends on how they are stored. Brussel sprouts on the stalk can be good for two weeks refrigerated and for a week on the counter. Loose sprouts can last about 1-2 weeks in the refrigerator. To extend their life, leave the bag they came in open to release built-up moisture.
When to harvest Brussel sprouts?
You’ll know when to harvest Brussel sprouts when they are about 1-2 inches (3-5cm) in diameter. If the sprouts have gone through a frost or even a freeze, they will have a better, more sweet taste to them, so if you’re anticipating a freeze, let the stalks hang out before you harvest for ultimate flavor.
How tall do Brussel sprouts grow?
Depending on the varietal, Brussel sprouts can grow up to 3 feet (1m). They appear like a mini trees in the garden but fortunately do not get tall like most real trees.
Are Brussel sprouts easy to grow from seed?
With some planning and forethought, Brussel sprouts are relatively easy to grow from seed. They don’t take up too much space since they grow vertically and can be harvested throughout the season, making them a worthwhile addition to the fall’s garden crops.
What month do you plant Brussel sprouts?
Brussels sprouts take a while to grow, so in climates where winters are cold, planting in early summer months like June will lead to your sprouts maturing around the end of fall or beginning of winter. In a milder climate, the middle or later summer months are acceptable for harvest around the middle or end of winter.