Growing Guides

Brussel Sprouts

Long Island Improved is a classic heirloom Brussels sprouts variety that has been a garden favorite since the 1890s. These compact plants grow about 24 inches tall and produce heavy yields of tight, mild-flavored sprouts measuring 1-2 inches in diameter. Flavor improves significantly after light frosts, which bring out a sweeter, richer taste. This variety is especially well suited for northern gardens and fall to winter harvests thanks to its excellent cold tolerance.

Brussels sprouts originated near Brussels, Belgium - which is how they got their name - and this American heirloom has been widely grown since the early 1900s.

How to Grow Long Island Improved Brussels Sprouts from Seed

• Sowing:
  Start seeds outdoors in late May to early June for a fall harvest. Sow seeds 1/2 inch deep and keep the soil consistently moist. Seedlings typically emerge in 7-14 days under good conditions.
  When plants reach 6-8 inches tall, transplant them into the garden, spacing plants 12-18 inches apart. Firm the soil around the roots and water thoroughly after planting.
• Growing Tips:
  Apply mulch to retain moisture and suppress weeds. In windy locations, staking may help support the plants. Remove yellowing lower leaves as plants mature to direct energy into sprout development. Control aphids early by spraying plants with a strong stream of water.
• Soil Requirements:
  Brussels sprouts prefer fertile, well-drained soil kept evenly moist. Ideal soil pH is 6.5-7.5. Germination occurs best around 70°F (21°C), while growing plants thrive in cooler temperatures near 60°F (16°C).
• Light:
  Full sun.
• Harvest:
  Sprouts are ready to harvest in approximately 80-115 days, with most crops maturing around 90-100 days. Harvest when sprouts are firm and 1-2 inches in diameter, starting from the bottom of the stalk where the earliest sprouts form. Light frosts improve sweetness and overall flavor.
  For extended late-season harvests, entire plants can be pulled up and hung upside down in a cool location. Sprouts will continue to mature for several weeks.
• Seed Saving:
  This open-pollinated heirloom requires a cold period (vernalization) to produce seed. In colder climates, dig plants in fall and store them in moist sand at about 40°F over winter. Replant in spring, allowing plants to flower and set seed. Harvest seed pods once they turn brown and dry, then store seeds in a cool, dry place. Seeds remain viable for up to five years.

Fast Facts

• Common Name: Brussels Sprouts
• Latin Name: Brassica oleracea var. gemmifera
• Origin: Mediterranean region and southwestern Europe
• Type: Open-pollinated heirloom, cool-season crop
• Life Cycle: Annual (grown as such)
• USDA Zones: 3-12
• Seeds per Ounce: ~8,000
• Sunlight: Full sun
• Height: ~24 inches
• Color: Green
• Uses: Culinary