How to Grow Redbor Kale

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Redbor Kale

Brassica oleracea var. acephala

vegetable

Redbor is a stunning ornamental and edible kale variety with deeply frilled, dark purple-red leaves that become more vibrant in cool weather. It's a cold-hardy brassica that adds both nutritional value and dramatic visual appeal to gardens and landscapes. The plant is prized for its nutrient density, beautiful foliage, and extended harvest season.

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Example Redbor Kale timeline · Pittsburgh, PA (Zone 6b)

Plant Redbor Kale
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
Harvest Redbor Kale
Around Jun 6

≈ 50 days after planting

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

Growing Conditions

☀️

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

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Water: Consistent moisture; 1-1.5 inches weekly. Keep soil evenly moist but not waterlogged. More frequent watering in hot weather.

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Spacing: 18 inches

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Days to maturity: 50-70 days from transplant; 70-90 days from seed

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Planting depth: 0.25-0.5 inches for seeds; transplant at same depth as nursery pot

Soil

Type: Well-draining, fertile loamy soil rich in organic matter

pH: 6.0-7.5

Amendments:

Compost aged manure nitrogen-rich fertilizer bonemeal for minerals

Growing Zones

Find your zone →

Thrives in zones 2-10; cold-hardy and improves in flavor after frost

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

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Growth Stages

Seedling

2-3 weeks

Tiny seed leaves emerge with true leaves following. Plant is delicate and small.

Keep soil consistently moist. Provide bright light and protect from damping off. Thin seedlings to prevent overcrowding.

Vegetative Growth

3-4 weeks

Plant develops rosette of deeply frilled leaves; stems thicken and foliage color deepens. Leaf texture becomes more pronounced.

Maintain consistent moisture and fertility. Begin fertilizing with balanced fertilizer every 2-3 weeks. Remove any yellow or damaged outer leaves.

Established Foliage

2-3 weeks

Plant reaches full size with mature frilly leaves displaying deep purple-red coloration. Color intensifies with cooler temperatures.

Begin light harvesting of outer leaves. Continue watering and fertilizing. Watch for pests. Color deepens after first frost.

Peak Production

4-8+ weeks

Mature plant at full harvest size; leaves are large, deeply textured, and richly colored. Can be harvested continuously.

Harvest outer leaves regularly to encourage new growth from center. Provide supplemental nitrogen for continued productivity. Remove any flowering stems.

Cold Season Enhancement

Ongoing through cold months

In fall/winter, color becomes even more vibrant and intense; texture becomes more tender. Flavor sweetens from starches converting to sugars.

Harvest cautiously in freezing temps when plants are thawed. Mulch to protect roots. Can produce through winter in mild zones.

Companion Planting

Plan your garden →

Plant with:

Beets Garlic Onions Potatoes Chamomile Dill Caraway Thyme Nasturtium Marigold

Avoid planting near:

Tomatoes Peppers Fennel Cabbage Broccoli Cauliflower Other brassicas (spacing issues and shared pests)

Common Pests

Use floating row covers before butterflies arrive. Hand-pick caterpillars. Apply Bacillus thuringiensis (Bt) or spinosad. Encourage parasitic wasps.
Hand-pick larger caterpillars. Apply Bt or spinosad spray. Plant trap crops like clover nearby. Use row covers.
Use row covers on seedlings. Dust with food-grade diatomaceous earth. Apply neem oil or insecticidal soap. Plant trap crops nearby.
Strong water spray to dislodge. Insecticidal soap or neem oil. Release beneficial insects like ladybugs. Reflective mulch deterrent.
Hand-pick and destroy (especially egg clusters). Crush eggs on leaf undersides. Remove plant debris. Use row covers.

Uses

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Raw Salads & Smoothies

Culinary

Tender young Redbor kale leaves are excellent in fresh salads, smoothies, and grain bowls. The mild flavor and tender texture (especially in younger leaves) make it more palatable raw than other kale varieties. [source]

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Cooked Dishes & Chips

Culinary

Mature leaves are ideal for sautéing, steaming, braising, and making crispy kale chips. The robust foliage holds up well to cooking and develops rich, complex flavors. [source]

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Nutritional Superfood

Medicinal

Redbor kale is exceptionally high in vitamins A, C, and K, plus calcium, iron, and antioxidants. The deep purple-red color indicates high levels of anthocyanins with potential anti-inflammatory properties. [source]

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Ornamental Landscaping

Household

With its dramatic purple-red frilly foliage, Redbor works beautifully as an ornamental edible in landscape beds, borders, and mixed plantings. The color deepens in cool weather, creating striking seasonal displays. [source]

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Beneficial Insect Support

Wildlife

Kale plants attract parasitic wasps and other beneficial insects that prey on garden pests. If allowed to flower, they provide pollen and nectar for pollinators. [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 plant is 6+ inches tall by snapping or cutting them at the base. Harvest in the morning after dew dries for best texture. Continue harvesting outer leaves to encourage new growth from center. Redbor improves significantly in flavor after first frost due to increased sugar content. Can be harvested continuously throughout growing season and into winter in cold climates. Cut entire plant at base if reaching end of season.

Fun Facts

🌱 Redbor kale's stunning purple-red color intensifies after exposure to frost, making it sweeter and more visually dramatic—some gardeners delay harvest until after the first hard freeze for peak flavor and appearance.
🌱 Kale is one of the oldest cultivated brassicas, and Redbor was developed more recently as a variety that combines ornamental beauty with excellent nutritional profile and cold hardiness.
🌱 A single mature Redbor plant can produce continuously for several months with proper harvesting technique, often outlasting other vegetables through fall and winter.

Gardening Terms

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

Damping Off Full Sun Mulch Partial Shade True Leaves

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