← Plant Guides

How to Grow Ornamental Kale 'Winterbor'

Wikimedia Commons

Ornamental Kale 'Winterbor'

Brassica oleracea var. acephala

vegetable

Winterbor is a cold-hardy ornamental kale variety prized for its deeply frilled, blue-green leaves that intensify in color after frost exposure. This non-heading kale reaches 18-24 inches tall and is grown primarily for decorative garden appeal and visual interest during autumn and winter months. Despite its ornamental designation, the tender leaves are edible and can be harvested for culinary use.

When should you plant Ornamental Kale 'Winterbor' in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Ornamental Kale 'Winterbor' timeline →

Example Ornamental Kale 'Winterbor' timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Ornamental Kale 'Winterbor'

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Ornamental Kale 'Winterbor'

    Around Jun 11

    ≈ 55 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Ornamental Kale 'Winterbor' dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily (partial shade tolerated in hot climates)
💧
Water: Consistent moisture, 1-1.5 inches weekly. Water at soil level to prevent leaf diseases. More drought-tolerant once established.
📏
Spacing: 18 inches
📅
Days to maturity: 55-90 days (ornamental color peaks 30-50 days after planting, intensifies with frost)
🌱
Planting depth: 0.25-0.5 inches for seeds; transplants at soil line

Soil

Type: Well-draining loamy soil with good organic matter
pH: 6.0-7.5
Amendments:
Compost Aged manure Peat moss or coconut coir Balanced slow-release fertilizer

Growing Zones

Find your zone →

Thrives in zones 3-9; color intensifies dramatically after first frost

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

Sign up free to see if Ornamental Kale 'Winterbor' grows in your zone — and get a personalized planting timeline.

Get my Ornamental Kale 'Winterbor' timeline →

Growth Stages

1

Seedling

2-3 weeks

Tiny green cotyledons emerge, followed by first true leaves with slight frilling

Keep soil consistently moist but not waterlogged. Provide bright light and protect from extreme temperature fluctuations. Thin seedlings to prevent leggy growth.

2

Vegetative Growth

4-6 weeks

Plant develops characteristic deeply frilled leaves; height increases to 6-12 inches with full leaf structure emerging

Water regularly and maintain consistent moisture. Fertilize every 3 weeks with balanced fertilizer or side-dress with compost. Remove any yellowed lower leaves.

3

Color Development

3-4 weeks

Blue-green coloring becomes more pronounced; leaves expand to full size with intricate ruffled edges. Plant reaches mature height of 18-24 inches.

Continue regular watering and feeding. As temperatures cool (below 50°F), color intensifies significantly. This is peak ornamental stage.

4

Peak Ornamental Stage

4-8 weeks (extends through winter in cold climates)

Leaves display vivid blue-green color with purple or red highlights after frost exposure. Ruffling is pronounced and striking.

Minimal care needed. Enjoy the visual display. Light harvesting of outer leaves won't diminish appearance. Protect from heavy ice/snow damage if desired.

5

Late Season/Spring Regrowth

Variable, 4+ weeks

In mild climates, plant may regrow or persist. In harsh winters, foliage quality declines after sustained freezing.

Remove dead or severely damaged leaves. In spring, may produce tender new growth. Eventually plants bolt and flower if temperatures warm.

Companion Planting

Plan your garden →

Plant with:

Ornamental Cabbage Autumn Mums Ornamental Grasses Pansies Violas Sedum Heuchera Dusty Miller

Avoid planting near:

Tomatoes Fennel Dill Cabbage family members (to prevent pest concentration) Strawberries

Common Pests

  • Use floating row covers during spring/summer. Bacillus thuringiensis (Bt) spray effective. Handpick larger worms. Remove affected leaves.

  • Bt spray most effective. Row covers prevent initial infestation. Encourage natural predators like parasitic wasps.

  • Row covers for young plants. Neem oil or insecticidal soap. Diatomaceous earth on foliage. Improve air circulation.

  • Handpick adults and egg clusters. Row covers. Kaolin clay spray. Remove plant debris where they overwinter.

  • Ensure good air circulation. Avoid overhead watering. Sulfur dust or baking soda spray. Remove severely affected leaves.

Uses

🍳

Edible Greens & Cooking

Culinary

Despite ornamental designation, Winterbor kale leaves are entirely edible and tender, particularly after frost which converts starches to sugars. Use in salads, soups, stir-fries, or sautéed as a winter green. [source]

🏠

Cut Flower & Floral Arrangements

Household

Winterbor's frilled foliage makes striking additions to cut flower arrangements, wreaths, and fall/winter table décor. Lasts 1-2 weeks in water and adds texture and color to bouquets. [source]

🎨

Autumn & Winter Garden Display

Craft

The primary purpose—Winterbor creates dramatic visual interest in garden beds and containers during cool seasons when many plants have faded. Color intensification after frost makes it a valuable seasonal landscaping plant. [source]

💊

Nutritional & Health Benefits

Medicinal

High in vitamins A, C, K, and antioxidants. Contains glucosinolates with potential anti-inflammatory and cancer-preventive properties. A superfood green when used culinarily. [source]

🦋

Pollinator Garden Support

Wildlife

If allowed to bolt in spring, Winterbor produces small yellow flowers attractive to early-season pollinators. The plant structure also provides shelter for beneficial insects. [source]

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

Harvest Tips

Winterbor is primarily grown for ornamental display and reaches peak visual beauty in autumn/winter. For culinary use, harvest outer leaves individually once plant is 8-10 inches tall—tender young leaves are most flavorful. Harvest in early morning for best texture. Leaves become sweeter and more tender after frost exposure. Avoid harvesting more than 1/3 of foliage to maintain plant structure and appearance. Plant retains ornamental quality even with light harvesting.

Fun Facts

  • 🌱 Winterbor's color deepens significantly in response to cold temperatures—some growers specifically time planting for fall harvest to maximize the dramatic blue-green and purple-red hues after frost.
  • 🌱 Unlike traditional heading kales and cabbages, Winterbor is a non-heading variety that maintains its open, bushy structure, making it naturally suited for ornamental display alongside standard landscape plants.
  • 🌱 The name 'Winterbor' reflects its exceptional cold tolerance; it can survive temperatures well below freezing and actually improves in flavor and tenderness after exposure to frost, making it one of the latest-harvest cool-season crops.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Bolt Compost Full Sun Partial Shade True Leaves
Shop Ornamental Kale 'Winterbor' plants and related plants at Plant Addicts →

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Ornamental Kale 'Winterbor' planting timeline

Tell us your zip code and we'll calculate exactly when to start Ornamental Kale 'Winterbor' seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Ornamental Kale 'Winterbor' timeline →