How to Grow Scotch Kale
Scotch Kale
Brassica oleracea var. acephala
vegetableScotch kale is a hardy, cold-tolerant leafy green with deeply frilled, blue-green leaves that form an open rosette rather than a tight head. It is highly nutritious, rich in vitamins A, C, and K, and becomes sweeter after frost exposure. One of the most cold-hardy brassicas, it can be grown year-round in many regions.
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Example Scotch Kale timeline · Pittsburgh, PA (Zone 6b)
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Plant Scotch Kale
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Scotch Kale
Around Jun 11≈ 55 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Scotch Kale dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 2-9; most productive in cooler zones 3-8
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Seedling
2-3 weeksTiny rounded cotyledons emerge, followed by wrinkled first true leaves. Plants are delicate and light green.
Keep soil consistently moist but not waterlogged. Provide bright light (grow lights 3-4 inches above seedlings) to prevent leggy growth. Maintain 65-70°F. Thin seedlings to prevent crowding.
Vegetative Growth
4-6 weeksPlants develop deeply frilled leaves on sturdy stems. The rosette structure becomes visible as leaves grow outward. Plants are blue-green and increasingly robust.
Maintain consistent moisture and 1-2 inches of water weekly. Apply balanced fertilizer every 3-4 weeks or use compost sidedressing. Thin to final spacing (18 inches) by 3-4 weeks. Monitor for cabbage worms and use row covers if needed.
Pre-Harvest Development
3-4 weeksOuter leaves reach full size and develop their characteristic deep blue-green color and frilly texture. Inner leaves continue to develop as outer ones are harvested.
Continue regular watering. Reduce nitrogen fertilizer to avoid excessive vegetative growth at expense of leaf quality. Begin harvesting outer leaves once they are 8+ inches long. Cold exposure (frost) enhances sweetness.
Continuous Harvest
8-12 weeks or until hard freezeMature plant produces new leaves continuously from the center. Outer leaves are large, deeply frilled, and dark green. Plant remains productive through cold months.
Harvest outer leaves regularly to encourage more growth. Plants can tolerate light frosts; flavor improves after light freeze. In mild climates, continue watering during dry spells. Remove any yellowed or damaged leaves.
Late-Season/Winter Production
Until hard freeze (below 10°F) or springIn cold climates, growth slows significantly but plant remains alive. Leaves become smaller and more densely packed; flavor is intensely sweet due to increased sugars.
Little to no watering needed if soil has adequate moisture from fall rains. Harvest sparingly to preserve plant energy. Mulch around base for insulation in zones below 5. Plant can produce through spring in mild zones.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Use fine mesh row covers before planting. Hand-pick caterpillars. Apply Bacillus thuringiensis (Bt) spray in early morning if infestation occurs. Encourage parasitic wasps.
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Hand-pick bugs and egg clusters (yellow/red striped eggs on leaf undersides). Use row covers. Plant trap crops like mustard nearby. Spray neem oil if needed.
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Use row covers for young plants. Dust with diatomaceous earth. Spray neem oil. Encourage beneficial insects. Mulch to discourage overwintering.
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Use yellow sticky traps. Spray with insecticidal soap or neem oil weekly if needed. Remove heavily infested leaves. Improve air circulation.
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Spray with strong water jet to dislodge. Use insecticidal soap or neem oil. Encourage ladybugs and lacewings. Remove heavily infested leaves.
Uses
Nutrient-dense green for salads and cooking
CulinaryScotch kale leaves are tender when young and excellent raw in salads or sautéed as a cooked green. The hearty texture holds up well to massaging for salads and roasting into chips. It pairs well with garlic, lemon, and olive oil. [source]
Smoothies and juices
CulinaryKale is a popular base for green smoothies and fresh vegetable juices, contributing vitamins and a mild flavor when blended with fruits and other ingredients. [source]
Antioxidant and anti-inflammatory properties
MedicinalScotch kale is exceptionally high in glucosinolates, sulfur compounds that may support detoxification and reduce inflammation. It is also rich in vitamins K, A, and C, supporting bone health, immune function, and antioxidant defense. [source]
Natural dye source
HouseholdKale leaves can be used to create natural dyes for fabrics and paper, producing yellow-green hues depending on mordant used. [source]
Beneficial insect and pollinator support
WildlifeKale flowers (if plants bolt in spring) attract beneficial insects, parasitic wasps, and pollinators, making them valuable in permaculture and integrated pest management systems. [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 once they reach 8-10 inches long, typically 55-75 days after transplanting. Pinch or cut leaves at the base of the stem, leaving the center intact to encourage continued growth. Harvest in the morning after dew dries for best texture. Young, tender leaves are milder; mature leaves are more robust and flavorful. Flavor sweetens significantly after light frosts (below 40°F). Continue harvesting outer leaves throughout the season—plants are more productive with regular harvesting. In cold climates, harvest can continue until hard freezes (below 10°F). In mild zones, winter and spring production is possible.
Fun Facts
- 🌱 Scotch kale becomes significantly sweeter after exposure to frost because the plant converts starches to sugars as a natural antifreeze mechanism to survive freezing temperatures.
- 🌱 Kale is one of the hardiest vegetables and can survive temperatures as low as 10-20°F, making it one of the last crops harvestable in fall and the first in spring.
- 🌱 Scotch kale was a staple crop in Scotland and Northern Europe for centuries before modern agriculture, earning it the name 'Scots kale' and representing a key winter food source before refrigeration.
Gardening Terms
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