How to Grow Kale Winterbor

Kale Winterbor

Brassica oleracea var. acephala

vegetable

Winterbor is a cold-hardy kale variety known for its deeply frilled, dark green leaves and exceptional frost tolerance. This vigorous grower produces tender, sweet leaves that improve in flavor after exposure to cold temperatures. It's an excellent choice for fall and winter harvests in most climates.

Growing Conditions

☀️

Sun: Full sun, 6-8 hours daily; tolerates partial shade in hot climates

💧

Water: Consistent moisture; 1-1.5 inches per week. Keep soil evenly moist but not waterlogged. More frequent watering during hot weather and establishment phase.

📏

Spacing: 18 inches

📅

Days to maturity: 50-60 days from transplant; 70-80 days from seed

🌱

Planting depth: 0.25 inches for seeds; transplants at soil line

Soil

Type: Well-draining loamy soil rich in organic matter

pH: 6.0-7.5

Amendments:

Compost aged manure nitrogen-rich fertilizer sulfur to lower pH if needed

Growing Zones

Find your zone →

Thrives in zones 2-10; exceptional cold hardiness makes it ideal for zones 2-8

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

Growth Stages

Seedling

2-3 weeks

Small plants with 2-4 true leaves emerge within 7-10 days. Cotyledons are round; true leaves show characteristic kale texture.

Maintain consistent moisture and 65-75°F soil temperature. Thin seedlings to prevent damping off. Provide bright light to prevent legginess.

Vegetative Growth

4-6 weeks

Rosette develops with increasingly frilled, dark green leaves. Plant grows 12-18 inches tall with a compact, sturdy base.

Water deeply and regularly. Apply balanced fertilizer every 3-4 weeks. Mulch around base to retain moisture and suppress weeds. Watch for pest pressure.

Pre-Harvest

2-4 weeks or ongoing

Plant reaches full maturity with dense foliage and deeply textured leaves. Flavor becomes sweeter after first frost (below 32°F).

Continue consistent watering and light fertilization. Allow frost exposure to enhance sweetness and tenderness. Remove any yellowed or damaged outer leaves.

Harvest

8-12 weeks of continuous harvesting

Outer leaves are ready to pick when 8-10 inches long. Plant can be harvested continuously or completely cut at soil level.

Harvest in morning after dew dries for best texture. Pick outer leaves first to encourage new growth from center. Use sharp knife or hand-pinch tender leaves.

Companion Planting

Plan your garden →

Plant with:

Beets Cabbage Cauliflower Celery Onions Potatoes Thyme Rosemary Dill Chamomile Garlic

Avoid planting near:

Tomatoes Peppers Eggplants Fennel Kohlrabi Strawberries Beans

Common Pests

Use row covers on young plants. Apply Bacillus thuringiensis (Bt) or spinosad. Hand-pick caterpillars. Remove damaged leaves promptly.
Use row covers early. Spray neem oil or spinosad. Increase nitrogen to speed plant establishment. Diatomaceous earth on foliage.
Spray with strong water spray. Apply insecticidal soap or neem oil. Introduce ladybugs or parasitic wasps. Avoid over-fertilizing with nitrogen.
Hand-pick bugs and egg clusters. Use row covers. Plant trap crops like mustard nearby. Spray neem oil if needed.
Bt spray is highly effective. Hand-pick larger caterpillars. Use row covers. Remove plant debris to reduce overwintering sites.

Uses

🍳

Fresh salads and raw snacks

Culinary

Winterbor's tender, deeply frilled leaves are excellent raw in salads when harvested young and tender. The sweet, mild flavor and attractive texture make it ideal for coleslaws, grain bowls, and crudités. [source]

🍳

Cooked vegetables and soups

Culinary

Larger leaves cook down beautifully in soups, stews, stir-fries, and sautés. The hearty texture withstands cooking while remaining tender. Popular in tuscan kale dishes and winter vegetable preparations. [source]

💊

Nutritional and immune support

Medicinal

Winterbor kale is exceptionally rich in vitamins K, C, and A, plus minerals like calcium, iron, and potassium. Contains glucosinolates and indoles, compounds studied for potential anti-inflammatory and disease-prevention properties. [source]

🏠

Ornamental garden display

Household

The deeply ruffled, dark green foliage is attractive enough for ornamental purposes. Winterbor adds textural interest to vegetable gardens and can be used in fall decorative plantings and holiday arrangements. [source]

🦋

Wildlife and pollinator support

Wildlife

If allowed to flower, kale produces yellow blooms that attract bees and other pollinators. The plant provides habitat for beneficial insects and can support biodiversity in the garden ecosystem. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Begin harvesting outer leaves when they reach 8-10 inches long, typically 50-60 days after transplanting. For best flavor, harvest after the first frost when sugars concentrate in leaves. Pick leaves in the morning. Use a sharp knife to cut leaves at the base, or pinch off tender leaves by hand. For maximum tenderness, harvest leaves before they become tough and fibrous (usually under 12 inches). The entire plant can be cut at the base near soil level, or harvest continuously from the outside in to extend productivity for 8-12+ weeks.

Fun Facts

🌱 Winterbor's flavor becomes noticeably sweeter after exposure to frost, as the plant converts starches to sugars as a natural antifreeze mechanism—a process called cryoprotection.
🌱 Kale is one of the most nutrient-dense vegetables available, with more vitamin C per calorie than oranges and more calcium per calorie than milk.
🌱 Winterbor can survive temperatures as low as 0°F to -10°F (and sometimes lower), making it one of the longest-season vegetables you can grow in cold climates.

Want personalized planting timelines?

Get started free