An Easy Guide to Growing Brussels Sprouts

Brussels sprouts have gained popularity thanks to their rich flavor and high nutritional value. Homegrown Brussels sprouts are fun to grow and taste delicious when roasted, steamed, or sautéed. Let’s dig into growing Brussels sprouts from seed so you’ll enjoy a bountiful harvest of these unique veggies in the spring and fall.

Growing Brussels sprouts from seed isn’t as challenging as it might first appear. These cabbage-like cole crops grow best in cool weather, which makes them ideal spring and fall vegetables.

However, the plants have a relatively long growing season compared to other leafy brassicas like cabbage, collard greens, and kale. Most types of Brussels sprouts take at least 100 days to reach maturity. Many gardeners opt for growing Brussels sprout seeds indoors in late winter or early spring to beat the heat. That way, the sprouts are ready before the weather warms up.

When deciding how to plant Brussel sprout seeds, the most influential factor is your growing climate. In this article, you’ll how to plant Brussel sprouts from seed and keep them thriving until harvest time.

How To Grow Brussels Sprouts from Seed

As long as they’re growing in the right conditions, Brussels sprout plants don’t require much extra care once they become established. They grow best when planted in full sun with six or more hours of direct sunlight throughout the day. However, they also tolerate partial shade and need protection from the afternoon sun in warmer climates.

The optimal temperature for growing Brussels sprouts is 45-80℉. Hot weather often triggers bolting, a stress response where the plant flowers prematurely. For the best results, plant Brussel sprouts seeds in late winter or early spring for harvesting in early summer. Sow seeds six to ten weeks before the expected first frost date for a fall crop. In some climates, growing Brussel sprouts is possible through the winter.

Brussels sprouts, or Brassica oleracea var. gemmifera, are members of the cabbage family along with broccoli, cabbage, cauliflower, collards, kale, radishes, and turnips. The sprouts form on tall stalks and resemble small cabbage heads when they mature.

Although they’re typically cultivated as annuals, Brussels sprouts are actually biennial plants. They have a two-year life cycle, developing leaves and roots in the first year and then flowers and seeds in their second year.

One of the best aspects of a home garden is trying unusual vegetable varieties that aren’t usually found at most grocery stores or farmers’ markets. It’s also beneficial to choose cultivars that are well-suited to your USDA planting zone and available garden space. Here are some of the best types of Brussels sprouts for growing at home.

Top Brussel Sprout Varieties

• Catskill (heirloom, 1-2 inch sprouts, strong stems that don’t require staking, rich flavor, 20-24 inches tall, 90-110 days to harvest)
• Diablo (hybrid, 1-2 inch sprouts, exceptional frost tolerance, 24-30 inches tall, 80-90 days to harvest)
• Green Gems (hybrid, 1-2 inch sprouts, stalks may require staking, 30-36 inches tall, 85-95 days to harvest)
• Hestia (hybrid, ½-1 inch sprouts, disease-resistant, sweet flavor, 24-30 inches tall, 90-100 days to harvest)
• Jade Cross (hybrid, ¼-1 inch sprouts, disease-resistant, 24-30 inches tall, 90-100 days to harvest)
• Octia (hybrid, ½-1 inch heads, early-maturing, insect resistant, rich flavor, 30-36 inches tall, 75-80 days to harvest)
• Long Island Improved (heirloom, 1-2 inch sprouts, disease-resistant, 20-24 inches tall, 85-110 days to harvest)
• Redarling (hybrid, 1-1 ½ inch sprouts, purple leaves, holds color when cooked, mildly sweet flavor, 30-40 inches tall, 130-145 days to harvest)

How to Plant Brussel Sprout Seeds

The best approach for growing Brussel sprout seeds depends on your USDA zone. If your region typically has mild spring weather, direct-sow the seeds two or three weeks before the usual last spring frost date or when your garden soil temperature is consistently above 40℉.

Start your Brussel sprout seeds indoors about four weeks before your average last frost date if you tend to have a short spring growing season. Plant seeds again in late summer for a fall or early winter harvest, so they mature in cooler weather.

For sprouting Brussels sprouts indoors, begin by filling a seedling tray, peat pots, or an egg carton with seed-starting potting soil. Pre-moisten your soil to avoid disturbing the seeds after planting. Sow the seeds a quarter-inch deep, then cover them with soil.

Maintain consistently moist soil while the seeds germinate, and the seedlings develop. The optimal temperature for germinating Brussels sprout seeds is 65-75℉. On average, the seedlings emerge in seven to ten days. Cold soil may cause slower germination.

Once your seedlings emerge, place the tray on a south-facing windowsill where they get at least six hours of bright light daily. If you don’t have a sunny place for them, use grow lights to prevent them from becoming elongated or “leggy.”

When to Plant Brussel Sprout Seedlings

Brussels sprouts are cold-hardy plants and can withstand temperatures down to 10℉ once mature. However, young seedlings are more delicate and should get transplanted outdoors after the last danger of frost passes in the spring. A week or two before planting your Brussels sprout seeds, cover your planting area with dark-colored mulch, organic compost, or a black tarp to warm the soil.

Transplant Brussels sprout seedlings once they’re four to six inches tall and have several sets of true leaves. Protect the tender young plants from insect and frost damage for the first several weeks with a cold frame or floating row covers.

Spacing between Brussels sprout plants is usually 18-24 inches, depending on which type you planted. Refer to the information printed on the seed packet or plant label for variety-specific instructions.

Ideal Growing Conditions for Brussels Sprout Plants

Brussels sprouts grow best in fertile soil that’s rich in organic matter and drains well. It’s beneficial to add organic compost or well-rotted manure to your garden soil in late fall or early spring.

Brussels sprouts need neutral to slightly acidic soil with a pH level between 6.5 and 7.0. Coffee grounds, pine sawdust, and sphagnum peat moss are excellent soil amendments that gradually lower the pH level and provide vital nutrients like calcium, manganese, magnesium, nitrogen, phosphorus, and potassium.

Brussels sprouts grow best in partial shade to full sun, where they get five or more hours of direct sunlight each day. The plants also need consistent moisture levels. Give your Brussels sprout plants one to two inches of water per week and a bit extra during especially dry or hot weather.

Brussels sprouts have shallow root systems and suffer when competing with weeds for water, nutrients, and space. Use organic material like bark mulch, leaves, grass clippings, or pine needles to insulate the soil, minimize weed growth, and retain moisture.

Tall varieties of Brussels sprouts sometimes become top-heavy and bend over once the sprouts begin maturing. In that case, stake it and loosely tie the stalk to the support.

Choosing the Best Fertilizer

Brussels sprout plants tend to be heavy feeders and benefit from regular fertilizing as they develop. Plant fertilizer contains three primary macronutrients: nitrogen (N), phosphorus (P), and potassium (K). Nitrogen encourages leaf growth, phosphorus promotes robust root systems, and potassium supports fruiting and flowering processes.

When transplanting Brussels sprout seedlings, add one tablespoon of nitrogen-rich, organic fertilizer to the bottom of the planting hole. Throughout the growing season, fertilize the growing plants every four to six weeks according to the directions listed on the label.

Growing Brussels Sprouts from Seed in Pots

If you don’t have a veggie garden or raised beds at home, don’t worry. Growing Brussels sprouts from seed is also possible in a container garden. It’s best to choose semi-dwarf varieties that stay relatively compact. The method for growing Brussels sprouts seeds is the same.

Find a container at least 12 inches deep, and allow 12-24 inches of pot width per plant. Avoid overcrowding your Brussels sprouts. This makes them more vulnerable to bacterial or fungal diseases and leads to stunted growth and a poor harvest.

Use a container with drainage holes to reduce the risk of root rot and other plant diseases. The risk of problems with pests and diseases is considerably lower for container gardens. However, it’s still essential to monitor your plants for signs of distress.

Harvesting and Storing Homegrown Brussels Sprouts

Brussels sprouts ripen from the bottom up around a central stalk. Pick the sprouts when the small heads feel dense and firm, and the leaves are still tightly wrapped.

Pick your Brussels sprouts when they’re about an inch or two in diameter for the best taste and texture. If they stay on the plant for too long, the buds may split open and turn bitter.

The sprouts are more accessible for harvesting if you trim away the leaf underneath first. Some gardeners prefer to pick Brussels sprouts by hand by gently twisting the bud. Others opt for using a clean, sharp pair of pruners to collect the sprouts without risking accidental damage to the plant’s main stem.

If the weather allows, a second, smaller crop of Brussels sprouts usually grows after your first harvest. These sprouts are typically smaller and less dense than the first ones. To encourage faster development, remove all the leaves from the lower two-thirds of the stalk.

For your fall Brussels sprouts harvest, it’s beneficial to wait until after the first autumn frost before harvesting. Exposure to a light frost reportedly gives Brussels sprouts and other brassicas a sweeter flavor and a more tender texture.

Brussels sprout leaves are also edible and highly nutritious. Prepare them similarly to other leafy greens like cabbage, Swiss chard, and kale. They’re delicious sautéed or steamed as a healthy side dish or raw in salads and sandwiches.

It’s best not to wash homegrown Brussels sprouts before storage. Place them in a perforated plastic bag in the crisper drawer of your refrigerator for up to a week. Freezing significantly extends the shelf life of fresh Brussels sprouts. Blanch them before freezing, and use frozen sprouts within a year.

Solutions for Common Pest and Disease Problems

Although Brussels sprouts are generally low-maintenance, there are still a few common pests and plant diseases to watch out for. The most effective defense against insects and plant disease is keeping your Brussels sprout plants healthy by providing sufficient light, nutrients, and water.

Some of the most frequent insects found feeding on Brussels sprouts include aphids, cabbage loopers, cabbage root maggots, cabbage worms, and cutworms. Protect tender seedlings with floating row covers to prevent insects from laying eggs on them. Keep cutworms away by placing a cardboard or aluminum foil collar an inch deep in the soil around the base of each plant. At the first sign of an insect infestation, spray all parts of the plant with an organic insecticide like horticultural oil, neem oil, or insecticidal soap.

Fungal diseases like powdery mildew and rust thrive in damp conditions and easily spread through splashing water droplets. Water using drip irrigation or a soaker hose to keep the leaves dry and provide adequate air circulation between plants. Treat affected plants with an organic copper or sulfur fungicide.

Clubroot is a soil-borne fungal disease that devastates brassica crops. It usually gets introduced to the garden on contaminated transplants. The disease causes the plants’ roots to grow stunted and misshapen. Unfortunately, no known effective treatment for clubroot exists. Acidic soil with a pH level between 6.5 and 6.8 helps eradicate clubroot spores.

If you’ve been wondering how to grow Brussels sprouts from seed, rest assured that it’s an easy and rewarding DIY project. They’re cool-weather crops that are ideal for a spring and fall harvest. Brussels sprouts flourish in fertile soil with plenty of water and sunshine. In the spring, harvest your Brussels sprouts before the weather gets warmer than 80℉. In the autumn, wait until after the first frost before picking those tender, sweet sprouts.

Do you have any questions or comments about growing Brussels sprouts from seed? Please share them in the comments! If you enjoyed this guide to growing Brussels sprouts from seed, please share it with your fellow gardening friends.