Botanical Classification
Redbor kale, scientifically classified as Brassica oleracea var. acephala, belongs to the Brassicaceae family, which includes cruciferous vegetables such as cabbage, broccoli, and Brussels sprouts. The acephala variety indicates non-heading brassicas, meaning it forms a loose rosette of leaves rather than a compact head.
Redbor is a specific hybrid cultivar of curly kale, bred for its striking color and ornamental appeal, sharing its genetic lineage with other kale varieties derived from wild Mediterranean cabbage. Its classification places it alongside other leafy greens selected for their edible and aesthetic qualities.
Origin and History
Kale has ancient roots in the eastern Mediterranean and Asia Minor, cultivated since around 2000 BCE by Greeks and Romans. Curly kale varieties, including Redbor’s predecessors, became staples in northern Europe during the Middle Ages for their cold tolerance. Redbor kale, a modern hybrid, was developed in Europe, likely in the Netherlands or Germany, in the late 20th century for its vibrant purple-red foliage, blending culinary and ornamental value.
Its name reflects its rich burgundy color. Popularized in the global health food movement, Redbor is now grown worldwide, including in Ecuador’s highlands, where cool climates and fertile volcanic soil support its cultivation for both local and export markets.
Identifying Characteristics
Redbor kale is a striking plant, known for its deeply curled, frilly leaves in vibrant shades of purple, burgundy, or magenta, which intensify with cooler temperatures. The leaves, similar to curly kale, grow in a loose rosette around a sturdy central stem, reaching heights of 2-5 feet, making it one of the tallest kale varieties. The foliage has a crinkled texture, and the stems are purple, edible when young but toughening with age.
Its vivid color and upright growth make Redbor a favorite for ornamental gardens, borders, and edible landscapes, distinguishing it from greener kale varieties.
Taste
Redbor kale has a robust, slightly bitter, and peppery flavor, akin to curly kale, with a mild cabbage-like undertone. Its texture is crisp and sturdy, though less fibrous than standard curly kale, especially when harvested young.
Cooking, such as steaming or sautéing, softens its bitterness, revealing a savory, earthy taste, while light frosts enhance sweetness by converting starches to sugars. Raw, it benefits from massaging with oil or acid to tenderize and mellow its flavor, making it suitable for bold, flavorful dishes.
Seasons/Availability
Redbor kale is a cool-season crop, thriving in spring and fall, with peak flavor after light frosts. It’s planted in early spring or late summer, maturing in 50-70 days. In Ecuador’s highland regions, like Cayambe, year-round cultivation is possible due to consistent cool temperatures (10-20°C) and fertile soil, ensuring steady supply for global markets.
In colder climates, it’s harvested from late summer through early winter, surviving light snow down to -7°C (20°F). Redbor is available year-round in grocery stores, fresh or as baby leaves, and occasionally frozen.
Culinary Uses
Redbor kale’s vibrant color and hearty texture make it a versatile ingredient in both culinary and decorative applications. Raw, its leaves are massaged for salads, pairing well with citrus dressings, nuts, or cheeses to balance its slight bitterness. It’s used in smoothies for a nutrient boost, retaining its vivid hue. Cooked, Redbor excels in soups, stews, or sautéed dishes with garlic and olive oil, holding its structure well.
It’s also baked into kale chips for a colorful, crispy snack. Young stems are edible, while mature ones can flavor broths, offering zero-waste potential in diverse cuisines.
Nutritional Value
Redbor kale is a nutritional powerhouse, low in calories (approximately 35 per cup raw) and rich in vitamins, minerals, and antioxidants. It’s an exceptional source of vitamins K, A, and C, providing over 100% of daily requirements per serving, supporting blood clotting, vision, and immune health.
It contains 2-3 grams of fiber per cup, promoting digestion, and is high in calcium, iron, and magnesium for bone and blood health. Its deep purple color indicates high levels of anthocyanins, antioxidants with anti-inflammatory and heart-protective properties, alongside quercetin and kaempferol. Redbor also offers folate and omega-3 fatty acids, making it a valuable addition to plant-based diets.
Cultivation of Redbor Kale
- Climate and Season: Redbor kale flourishes in cool weather, with optimal temperatures between 15-24°C (60-75°F). Plant in early spring or late summer for spring and fall harvests. In Ecuador’s highlands, year-round cultivation is possible due to consistent cool climates. Light frosts enhance color and sweetness, but protect from hard freezes below -7°C (20°F).
- Site Selection: Choose a site with full sun (6-8 hours daily) to promote vibrant leaf color and growth, though partial shade is tolerated in warmer areas. Ensure good air circulation to reduce fungal disease risk, especially in humid regions like parts of Ecuador.
- Soil Requirements: Redbor kale prefers fertile, well-drained, loamy soil with a pH of 6.0-7.5. Enrich with organic matter like compost or aged manure. In Ecuador, test volcanic soils for acidity and amend with lime if below 6.0 to optimize nutrient uptake.
- Soil Preparation: Loosen soil to 12 inches deep before planting, mixing in 2-3 inches of compost or organic matter. Remove rocks and debris to support root development. A soil test ensures proper pH and nutrient balance for robust, colorful foliage.
- Planting: Sow seeds ¼-½ inch deep, spacing 12-18 inches apart in rows 18-24 inches apart. Alternatively, transplant seedlings started indoors 6-8 weeks earlier for faster growth. In Ecuador, indoor seed starting protects against variable weather conditions.
- Watering: Maintain consistent soil moisture, providing 1-1.5 inches of water weekly, avoiding waterlogging. Use drip irrigation to keep leaves dry, reducing disease risk in humid climates. Mulch to retain moisture and regulate soil temperature.
- Fertilization: Apply a balanced fertilizer (e.g., 10-10-10) at planting, followed by a nitrogen-rich fertilizer (e.g., fish emulsion) every 4-6 weeks. Avoid excess nitrogen to prevent soft leaves that attract pests and maintain vibrant coloration.
- Mulching: Add a 2-3 inch layer of organic mulch, such as straw or bark, to conserve moisture, suppress weeds, and keep roots cool. This is particularly effective in Ecuador’s fluctuating climates to stabilize soil conditions and enhance plant health.
- Pest Management: Monitor for pests like aphids, cabbage worms, and flea beetles, which target kale leaves. Use row covers, neem oil, or introduce beneficial insects like ladybugs. Hand-pick caterpillars for organic control, especially in small gardens.
- Disease Control: Prevent fungal diseases like powdery mildew and black rot by ensuring good air circulation and avoiding overhead watering. Rotate crops every 2-3 years to minimize soil-borne pathogens, a critical practice in Ecuador’s intensive farming areas.
- Harvesting: Harvest outer leaves when 6-8 inches long, about 50-70 days after planting, cutting close to the stem. Leave the central bud intact to encourage regrowth. Regular harvesting promotes continuous leaf production and maintains plant vigor.
- Succession Planting: Sow seeds every 2-3 weeks in spring or fall for a steady supply. In Ecuador’s highlands, staggered planting ensures year-round harvests due to the mild climate, maximizing garden productivity for both culinary and ornamental use.
- Storage and Preservation: Store fresh Redbor kale in a refrigerator at 0-4°C (32-40°F) in a perforated plastic bag for up to 2-3 weeks. For long-term storage, blanch leaves for 2-3 minutes, cool in ice water, dry thoroughly, and freeze to preserve nutrients. Wash and dry before storing to maintain freshness.