Quick Growing Facts

When & Where to Grow ‘Catskill’ Brussels Sprouts

Brussels sprouts need a long, cool growing season and are best when the sprouts mature in cool to cold weather. ‘Catskill’ is especially suited to fall and early winter harvests, but can also be grown for late-spring harvest in regions with cool summers.

• Fall crop (recommended): Start seeds indoors 14–16 weeks before your first expected hard frost. Transplant outdoors 10–12 weeks before that frost date so sprouts mature in cool weather.
• Spring / early summer crop (cool-summer areas): Start seeds indoors 4–6 weeks before last frost and transplant 1–2 weeks before last frost. Aim for heads to develop before sustained heat.
• Location: Full sun location with good air circulation. Raised beds or well-prepared garden beds are ideal.
• Climate note: In hot-summer climates, Brussels sprouts usually perform best as a fall/winter crop, not sown for midsummer maturity.

Soil Preparation

As a heavy-feeding brassica, Brussels sprouts benefit from deep, fertile soil that holds moisture but drains well. Good preparation supports tall, sturdy plants and tight sprouts.

• Loosen the top 12–14 in (30–35 cm) of soil and remove weeds, roots, and stones.
• Incorporate generous amounts of compost or well-rotted manure before planting.
• For poorer soils, add a balanced organic fertilizer according to label rates at bed preparation.
• Brassicas prefer slightly acidic to neutral soil; if soil is very acidic, add garden lime as needed ahead of planting.
• Ensure good drainage; standing water or very compacted soil can stunt plants and increase disease risk.

Starting ‘Catskill’ Indoors

Starting Brussels sprouts indoors lets you control early growth and time the harvest for cool weather. This is the most reliable method for most climates.

• Sow 1–2 seeds per cell or small pot filled with seed-starting mix, about 1/4 in (6 mm) deep.
• Maintain 65–75°F (18–24°C) until germination, then provide strong light (south-facing window or grow lights).
• Thin to one strong seedling per cell once true leaves appear.
• Keep the mix evenly moist but not soggy; avoid letting seedlings dry out or become waterlogged.
• Begin hardening off 7–10 days before transplanting by gradually exposing seedlings to outdoor conditions.

Transplanting & Spacing

Correct spacing and careful transplanting help ‘Catskill’ produce sturdy stalks loaded with evenly sized sprouts.

• Transplant when seedlings are 4–6 in (10–15 cm) tall with several true leaves and strong stems.
• Set plants 18–24 in (45–60 cm) apart in rows 24–30 in (60–75 cm) apart.
• Plant seedlings slightly deeper than they grew in trays, up to the first true leaves, to anchor plants firmly.
• Water well after transplanting to settle soil around roots.
• In windy areas, consider staking plants later in the season when stalks are heavy with sprouts.

Direct Sowing Outdoors (Optional)

Direct sowing Brussels sprouts is possible in regions with long, cool seasons, but indoor seed starting offers more control over timing. If you direct sow:

1. Sow seeds about 1/4–1/2 in (6–12 mm) deep in rows 24–30 in (60–75 cm) apart.
2. Sow 2–3 seeds every 12–18 in (30–45 cm), then thin to one strong plant per cluster.
3. Keep soil consistently moist for reliable germination.
4. Protect young seedlings from flea beetles and caterpillars with row covers if needed.

Watering & Feeding

Brussels sprouts take many weeks to mature and need steady moisture and nutrients throughout the season. Stress from drought or hunger can lead to loose, small, or bitter sprouts.

• Watering: Provide about 1–1.5 in (2.5–4 cm) of water per week, more in hot or sandy conditions. Water deeply at the soil level.
• Mulch: Add a layer of compost, straw, or leaf mold to conserve moisture, reduce weeds, and moderate soil temperature.
• Feeding: Side-dress with compost or a balanced organic fertilizer 3–4 weeks after transplanting, and again midway through the season. Extra nitrogen early helps strong leafy growth; later, balanced feeding supports sprout development.

Plant Care: Topping & Leaf Removal

Some gardeners “top” Brussels sprouts and remove lower leaves to encourage uniform sprout sizing and easier harvest.

• When sprouts have formed along most of the stalk and are starting to size up, pinch or cut out the growing tip (top) of the plant. This directs energy into enlarging existing sprouts.
• Remove yellowing or damaged lower leaves as the season progresses to improve airflow and access for harvesting.
• Avoid stripping too many healthy leaves at once, as the plant needs foliage to photosynthesize and feed the sprouts.

Pests & Diseases

Brussels sprouts share many pests and diseases with other brassicas like cabbage, kale, and broccoli. Prevention and regular monitoring are key.

• Cabbage worms & loopers: Green caterpillars that chew leaves and sprouts. Hand-pick or use organic Bt (Bacillus thuringiensis) as needed.
• Flea beetles: Tiny beetles that make many small holes in leaves. Use floating row covers and keep plants vigorous with water and nutrients.
• Aphids: Often cluster in sprout crevices and on new growth. Spray with a strong jet of water or use insecticidal soap.
• Slugs & snails: Can damage young plants and lower leaves. Use traps, barriers, and hand-picking, especially in damp weather.
• Clubroot & soil diseases: Rotate brassicas to new beds every 3–4 years, improve drainage, and maintain proper soil pH.

Harvesting ‘Catskill’ Brussels Sprouts

Sprouts mature from the bottom of the stalk upward. Harvest in stages as they reach usable size, leaving smaller sprouts higher on the plant to develop.

• Begin harvesting when sprouts are about 1–1.5 in (2.5–4 cm) in diameter, firm, and tightly closed.
• Start at the bottom of the stalk and work upward over time.
• Twist or snap sprouts off the stem with your fingers, or cut with a small knife.
• Sprouts become sweeter after one or more light frosts; flavor often improves significantly with cold.
• In some cases, the entire stalk can be cut and brought indoors once most sprouts are mature; store stalks cool and moist to extend freshness.

Storing & Using Brussels Sprouts

• Remove any loose or yellowing outer leaves and trim stems.
• Store loose sprouts in a breathable or lightly sealed bag in the refrigerator; use within 1–2 weeks for best quality.
• Whole stalks can be kept in a cool, humid place or refrigerator for several days; snap off sprouts as needed.
• Sprouts can be blanched briefly and frozen for long-term storage.
• Use roasted, sautéed, steamed, or shredded in salads and slaws; ‘Catskill’ sprouts are flavorful and hold texture well in cooking.

Saving Seed from Brussels Sprouts

Brussels sprouts are biennials and flower in their second year after cold exposure. They are insect-pollinated and can cross with other Brassica oleracea crops (cabbage, kale, broccoli, cauliflower, collards), so isolation is required for true-to-type ‘Catskill’ seed.

• In cold climates, dig selected healthy plants in fall and store roots in a cool, humid place; replant in spring. In mild climates, overwinter plants in the garden with mulch for protection.
• Allow replanted or overwintered plants to send up tall flower stalks in the second season.
• Plants produce yellow flowers followed by long, slender seed pods.
• When pods turn tan-brown and dry, cut stalks into a paper bag or over a tray before they shatter.
• Dry thoroughly, then thresh pods to release seeds and winnow out chaff.
• Store seeds in a labeled, airtight container in a cool, dark, dry place; under good conditions, seeds remain viable for several years.

Tips for Success

• Plan carefully so sprouts mature in cool weather, ideally with some frost, for best flavor and texture.
• Use row covers early in the season to protect young plants from cabbage worms and flea beetles.
• Keep plants evenly watered and well-fed throughout their long growing season.
• Remove yellowing leaves and harvest regularly from the bottom up to keep plants healthy and productive.
• Rotate brassicas to a different bed every year to reduce pest and disease buildup in the soil.

Note: Growing conditions and timing vary by region. Adjust sowing dates, watering, and frost/heat protection to match your local climate and weather patterns.