If you would like to learn how to grow Brussel sprouts (actually spelled Brussels) please keep reading! Growing Brussels sprouts was first popular in Belgium and the lower countries of Europe where the climate is cooler. Their long growing season (late spring to late fall) allows for light frosts to improve the flavour and increase the nutrients in each bud. Brussel sprouts are a hardy vegetable and high in vitamins and antioxidants. They taste sweetest if exposed to a couple frosts, and can be eaten raw, baked, roasted, or steamed and make a great side to any meal.
Growing Conditions for Brussels Sprouts
Growing Brussels sprouts is best accomplished in cooler weather in temperatures around 60-65°F/15.5-18°C. They are one of the last crops to harvest in the garden and can survive light to medium frosts. Similar to broccoli or cauliflower, Brussels sprouts prefer well-drained soil and do not require excessive nutrients in the soil. They need regular and generous watering at the root and also on the leaves.
How to Grow Brussels Sprouts
When to Plant - Seeding
Start seeds indoors in mid to late spring (end of May - early June). Seeds are normally grown for 5-6 weeks indoors before transplanting. (For further information on planting indoors, please see our section on planting, thinning, and potting.
Planting or Transplanting Brussels Sprouts in an Outdoor Garden
- Transplant your seedlings to an outdoor garden in mid-August (or when they have 6-8 true leaves) to take advantage of the cooler but mild climate. The transplants will need somewhere around 50-70 days in the garden before the first frost. While Brussels sprouts don't like the heat of summer, they are hardy enough to thrive in both summer as well as in cooler temperatures.
- Tranplants should be placed 18-24 inches apart in rows that are ~33 inches apart to allow proper growth.
- For direct sewing (planting the seeds directly into your vegetable garden), plant the seeds no later than 4 months before the first Fall frost. Plant the seeds 1/2 and inch deep and 2-3 inches apart. Thin out the smaller seedlings - the plants should be ~18 inches apart by the time the plants are 6 inches tall.
Watering Brussels Sprouts
An important part of learning how to grow brussel sprouts is watering. Water well at time of planting/transplanting at the root. Do not use a high pressure stream as the new leaves are delicate. Growing Brussels sprouts require constant watering during the growing season. Keep the soil damp, but avoid creating standing water in order to avoid disease.
Fertilizing Brussels Sprouts (at 3 weeks)
If you are planning to fertilize, you can add an organic fertilizer 3 weeks after transplanting. Although it is not essential to fertilize, Brussels sprouts grow well in cooler soil that is rich in nitrogen. For Brussels sprouts, it is best to use nitrogen-rich fertilizer such as blood meal, cottonseed meal, or composted manure. Be cautious - too much nitrogen in the soil will produce lots of leaves, but the sprouts will be fewer and small.
Brussels sprouts also need more boron than most other vegetables. Boron is a plant nutrient used in minute quantities by all plants; without it, Brussels sprouts develop hollow stems and small buds. If your plants have shown these symptoms, you can add boron to the soil by dissolving 1 level tablespoon of borax in 5 quarts of water and sprinkling it evenly over 50 square feet of bed.
Care and Maintenance - How to Grow Brussels Sprouts (from Planting to late October)
In June, you can add mulch to retain moisture and keep the soil temperature cool.
Do not cultivate the soil as the roots are shallow and susceptible to damage!
Throughout the season, if any of the lower leaves of the plant show any yellowing, strip them from the stalks. Some believe that the sprouts develop better if the lower 6-8 leaves are removed from the sides of the stalk as the sprouts develop. Two or three lower leaves can be removed each week, but several of the largest, healthiest, fully expanded upper leaves should always be left intact on top to continue feeding the plant.
Harvesting Brussels Sprouts (in late Fall)
The best part of learning how to grow brussel sprouts is harvest! Brussels sprouts are ready to harvest when the tiny heads are firm, green, and 1 to 2 inches in diameter. Remove sprouts by twisting them until they break away from the plant.
While removing the lower sprouts, you can also remove yellowing leaves; the plant continues to grow upward, producing more leaves and sprouts. The best-quality sprouts are produced during sunny days with light frosts at night.
Note: In colder climates, gardeners often bury Brussels sprouts plants up to their tops in hay or leaves in late fall. This will keep the plant longer.
Pests/Diseases - How to Grow Brussel Sprouts
- Cabbage Root Maggots
- Flea Beetles
- Downy Mildew
- White Mold
Wintering and Storing Brussels Sprouts
Brussels Sprouts can be over-wintered in the garden right on the stalk. They need to be mulched, or covered with a structure wrapped with burlap, before the hard freeze. Mulching helps to keep them at an even temperature and prevents the constant thaw/freeze which promotes rot. For mulch you can pile straw or hay in a mound around the plants, and/or cover with a cardboard box.
To store Brussels sprouts, keep them in the fridge for at least a few weeks. Do not wash them before you store them, simply bag them unwashed and rinse them only before use. Stored Brussels sprouts will be the most flavorful up to 5 days in the fridge, but will stay fresh up for cooking for up to a few weeks. In the freezer, they will keep for several months.
If you have great tips about how to grow brussels sprouts we'd love to hear them in the comment section below!