Long Island Improved Brussels Sprouts Seeds

Long Island Improved Brussels Sprouts — The 1890s Heirloom That Predates Catskill and Remains the Most Popular Variety

Originating around the 1890s, Long Island Improved (Brassica oleracea var. gemmifera) is the most popular Brussels sprouts variety ever developed — and still is today, even though it is sometimes mistaken for the Catskill strain developed by Arthur White of Arkport, NY in 1941. Long Island Improved is the older variety. Sturdy 30–36-inch stalks with 24–30-inch spread produce firm, light green sprouts 1–2 inches in diameter with a strong cruciferous cabbage flavor that sweetens beautifully after frost. Very tolerant of frost and cold climates. No staking required. Excellent for freezing. 80–100 days.

Why Grow Long Island Improved?

• The original — older than Catskill — 1890s heirloom, still the most popular Brussels sprouts variety
• Frost-tolerant and cold-hardy — thrives in zones 2–10; flavor sweetens after frost
• Sturdy 30–36 inch stalks — no staking required; robust and decorative in the garden
• Firm 1–2 inch sprouts — light green, tight, and prolific; strong cabbage flavor
• Bottom-up harvest — sprouts mature from the bottom of the stalk upward
• Force-ripen trick — cut the top of the plant 3 weeks before desired harvest to force all sprouts to mature simultaneously
• Excellent for freezing — firm texture holds well through blanching and freezing
• Open-pollinated heirloom — save seed year after year

Growing Notes

Direct sow or start indoors 6–8 weeks before last spring frost. Sow ½ inch deep, 4–6 inches apart; thin or transplant to 24–30 inches apart in rows 30 inches apart once true leaves establish. Germination takes 7–14 days. Prefers fertile, moist, well-drained soil with organic matter, pH 6.0–7.0. Full sun to partial shade. Water 1 inch per week; keep soil consistently moist — drought causes bitterness. Optimal growing temperature 45–75°F. Prune yellowing leaves and lower-half leaves as sprouts emerge for most robust production.

Harvest: Sprouts mature bottom-up — harvest firm 1–2 inch sprouts from the bottom of the stalk first. Twist or cut to detach. To harvest all sprouts at once, cut the top of the plant 3 weeks before your target harvest date to force simultaneous maturity. Entire stalk can be cut at the base when all sprouts are firm.

Watch for: Cabbage worms, flea beetles, thrips, slugs, and aphids. No serious diseases but monitor regularly.

Packed and shipped by Box Garden Seeds LLC — heirloom seeds grown without GMOs, selected for flavor, resilience, and your garden’s success.