Description

The American Achievement, Cold-Hardy Excellence and the Sprout of Perfect Abundance

Long Island Improved Brussels sprouts are the kind of harvest that arrives as the year turns.

When the garden air sharpens and the mornings taste like frost, this plant stands tall and unbothered. Its sturdy stalks and broad green leaves stand firm and tall, and along the stem, dozens of tight little cabbages form like beads on a rosary. There’s something deeply satisfying about Brussels sprouts grown the way they were meant to be grown: slowly, patiently, in cool weather, until the cold sweetens them.

Each sprout is a miniature crown: firm, deep green, and tightly wrapped. Roast them, and they turn sweet and nutty with crisp edges. Sauté them, and they become tender and rich. And because this variety is famously productive, you don’t just get a handful; you get a whole season’s worth of abundance climbing up a single stalk.

A whisper of history

Brussels sprouts were shaped into their distinctive form in the Low Countries (around modern Belgium and the Netherlands), where gardeners selected cabbage relatives to produce tight little heads along a tall stem.

Long Island Improved is a North American achievement. It was selected on Long Island, New York, for uniform sprouts, strong cold tolerance, and dependable yields, ideally suited to northern gardens where fall is long, and flavour deepens with every cold night.

What You’ll Grow

• Plant type: Cool-season annual brassica (grown for sprouts along a tall stalk)
• Growth habit: Upright, sturdy stalk with sprouts forming from bottom to top
• Plant height: typically 60–90 cm (24–36 in)
• Spread: typically 45–60 cm (18–24 in)
• Sprouts: typically 2.5–5 cm (1–2 in), tight and uniform
• Yield: often 50–100+ sprouts per plant in good conditions
• Colour: rich, deep green
• Flavour: sweet, nutty, and fuller after frost

Days to maturity: typically 90–110 days from transplant to first harvest; harvest continues for weeks.

Growing Instructions

Brussels sprouts ask for two things: time and steady care. Give them both, and they will reward you when everything else is fading.

When to Plant

• Start 6–8 weeks before the last spring frost indoors
• Transplant outdoors after the last spring frost once seedlings are sturdy
• For many Canadian gardens, a mid-summer sowing for fall harvest also works well (timing depends on your first frost)

Starting From Seed (Indoors)

• Sow 6 mm (1/4 in) deep
• Keep evenly moist
• Germination: typically 7–14 days
• Provide strong light and cooler conditions to prevent stretching

Hardening Off

• Harden off seedlings for 7–10 days before transplanting

Planting + Spacing

• Full sun is best (6–8+ hours)
• Space plants 45–60 cm (18–24 in) apart
• Rows: 75–90 cm (30–36 in) apart
• Plant into rich, well-drained soil; firm in well so roots settle quickly

Soil + Feeding

Brussels sprouts are heavy feeders.

• Target pH 6.0–7.0
• Work in compost or well-rotted manure before planting
• Side-dress with compost or balanced fertilizer during the season
• Avoid letting plants stall (stalled growth = smaller sprouts)

Watering

• Provide 2.5–5 cm (1–2 in) of water per week
• Keep moisture consistent for tender sprouts
• Mulch to conserve moisture and keep roots cool

Staking + Wind

• Plants can get tall and top-heavy. Stake if needed, especially in windy sites

Pest Notes (Brassica Reality)

• Watch for cabbage worms and aphids
• Row cover early helps prevent egg-laying
• Hand-pick caterpillars; rinse aphids off with water; treat as needed with approved organic methods

Sprout Quality Tip: Topping

• When lower sprouts are about 1–1.5 cm (1/2 in) wide, you can remove the growing tip (top rosette)
• This directs energy into sprout sizing and uniformity

Harvesting (The Long, Beautiful Pick)

Brussels sprouts ripen from the bottom up.

• Begin harvesting when sprouts are firm and 2.5–5 cm (1–2 in)
• Twist or cut sprouts from the stalk
• Keep harvesting upward as new sprouts tighten

Frost = Better Flavour

• Brussels sprouts become sweeter after frost because cold converts starches to sugars
• Long Island Improved is notably cold-hardy and can handle hard autumn weather

Preserving + Storage

• Fresh: store unwashed sprouts in the fridge
• Blanch + freeze: best for long-term storage
• Roast then freeze: a great meal-prep option (reheat in a hot oven)

Culinary Notes: Sweetness Earned by Cold

Long Island Improved is made for roasting. This is where its sweetness and nutty depth shine.

• Roast: 400–425°F until caramelized (25–35 minutes)
• Sauté: halved sprouts with garlic and butter/olive oil
• Braise: broth or cream for a rich, comforting dish
• Grill: halved sprouts, lightly charred
• Raw: finely shredded in salads for crunch

Prep Tip

• Remove any damaged outer leaves
• Halve larger sprouts for even cooking
• Don’t fear the crisp edges. Those are the best part

Canadian Climate Notes

This is a Brussels sprout for Canadian fall.

• Plan for a long season: start early enough to hit peak harvest in autumn
• Cool nights improve flavour; frost makes them sweeter
• Mulch and steady watering help plants stay unstressed through late summer

Growing zones: 2–10 (annual; cool-season crop).

Seed Saving

Brussels sprouts are typically grown as a biennial for seed.

How to Save Seed

1. Select your best plants (vigorous, uniform sprouts, strong flavour)
2. Overwinter plants where possible (or protect in cold frames in harsh climates)
3. In the following season, allow plants to bolt and flower (yellow blooms)
4. Let the seed pods mature and dry on the plant until brown
5. Harvest pods, finish drying indoors, then thresh to release the seed
6. Store seed cool, dark, and dry

Isolation & Cross-Pollination

• Brussels sprouts cross with other Brassica oleracea types (cabbage, kale, broccoli, cauliflower, Brussels sprouts, collards)
• For pure seed, isolate by distance (as practical) or only let one B. oleracea type flower

Seed viability: typically 4–5 years

Long Island Improved is the American sprout of abundance. It’s built for cold, bred for productivity, and at its best when the season turns quiet, and the garden starts tasting like sweetness earned.