Peren 06 Sea Kale
layout: base.njk title: "Sea Kale" plantName: "Crambe maritima" category: "Perennials" description: "Growing guide for Sea Kale in West Virginia Zone 6b/7a" tags: planting-guide
Type: Perennial
Family: Brassicaceae (Mustard/Cabbage family)
Sun: Full sun
Water: Low to moderate (drought-tolerant once established)
Soil pH: 7.0-8.5 (prefers alkaline)
Hardiness: Zones 3-9
📅 Planting Calendar (WV Zone 6b/7a)
| Method | Timing | Notes |
|---|---|---|
| Direct sow seeds | March 15 - April 30 | ½" deep, thin to 18-24" |
| Start seeds indoors | February 1 - March 1 | Transplant after frost, 8-10 weeks before |
| Plant root cuttings | March 15 - April 30 | 3-4" root sections, planted horizontally |
| Divide established | Every 5-7 years | Spring, when plants are dormant |
| First harvest | Year 2 | Blanch shoots in spring (see below) |
🌱 Expected Yield
- Per plant: 1-2 lbs blanched shoots per season
- Per patch (10'x10'): 8-12 lbs (6-8 plants)
- Lifespan: 15-20+ years in same location
🌿 Growing Conditions
- Soil: Sandy, well-drained, alkaline soil. Native to seacoasts—tolerates salt, poor soil, wind. Does NOT like heavy clay or wet feet.
- Fertilizer: Very light feeder. Excess fertilizer reduces flavor. Light compost or seaweed meal in spring.
- Mulching: Gravel or shell mulch mimics natural habitat. Helps drainage. Avoid thick organic mulch (retains too much moisture).
- Companions: Asparagus, sage, rosemary (all prefer similar conditions)
- Avoid: Moisture-loving plants, acid-lovers (blueberries, potatoes)
- Pests: Generally pest-free. Cabbage loopers occasionally—hand-pick. Deer resistant.
- Diseases: Root rot if soil stays wet. Ensure excellent drainage. Virtually disease-free in proper conditions.
- Containment: Not invasive. Forms large clumps (2-3' diameter). Plant where it can spread. Deep taproot makes relocation difficult.
Critical Note: Traditional harvest method involves BLANCHING. In early spring (March), cover crowns with 6-8" of sand, soil, or special forcing pots. Harvest pale shoots after 4-6 weeks. Unblanched leaves are edible but bitter. Blanching produces tender, sweet, asparagus-like shoots.
🏺 Heirloom Varieties
Note: Sea kale has virtually no named varieties—it's grown as wild-type or landrace selections.
'Lillywhite' Sea Kale
- Source: UK seed exchanges, rare collections
- Notes: 1800s English selection. Large, thick leaves. Very winter-hardy. Traditional variety.
Common Sea Kale
- Source: Baker Creek (rare), European seed networks
- Notes: Wild-type. Blue-green wavy leaves. White flower clouds in summer. Extremely hardy. Salt-tolerant.
Selected Horticultural Type
- Source: Johnny's Selected Seeds (occasionally), rare seed savers
- Notes: Selected for larger shoots, better blanching quality. More vigorous than wild type.
📜 Cultural History & Domestication
Domesticated: 1700s England, from wild coastal plants
Archaeological Evidence: Native to seacoasts of western Europe, from Baltic to Mediterranean. Archaeological evidence of foraging from Mesolithic coastal settlements (6000+ years ago).
Historical Record: - Wild sea kale foraged by coastal Europeans for millennia - First cultivated in England 1700s by aristocratic gardeners - William Curtis (botanist) described sea kale culture in Flora Londinensis (1775-1798) - Thomas Jefferson grew sea kale at Monticello (1809-1812), imported seed from France - Victorian England (1837-1901): Sea kale became fashionable vegetable, grown in royal gardens - Special sea kale forcing pots invented—terracotta pots with drainage holes, placed over crowns - By 1850s, sea kale common in upper-class English gardens - Declined after WWI (labor-intensive, asparagus became preferred) - Preserved by heritage gardeners and seed savers - Modern rediscovery: Permaculture values its perennial nature and low maintenance
Cultural Significance: - Symbol of English coastal gardening tradition - Victorian gardeners prized sea kale as status vegetable (labor-intensive to blanch properly) - Traditional British cuisine: Blanched shoots served with butter, like asparagus - Coastal foraging tradition: Wild sea kale still harvested from British beaches - Featured in 1800s cookbooks: Mrs. Beeton's Book of Household Management (1861) includes sea kale recipes - Ornamental value: Beautiful blue-green foliage, clouds of white flowers (honey plant) - Salt tolerance made it valuable for coastal gardens
🌾 Seed Saving / Propagation
- Seed method: Plants produce dramatic clouds of white flowers (June-July). Seeds form in small pods. Harvest when brown and dry. Seeds are round, dark brown.
- Isolation: 2+ miles between varieties (insect-pollinated, crosses with other Crambe species)
- Viability: 4-6 years when stored cool and dry
- Division: Every 5-7 years in spring. Difficult due to large taproot. Use sharp spade, divide crown into sections with roots and buds.
- Root cuttings: BEST propagation method. In late winter/early spring, dig 3-4" sections of thick roots. Plant horizontally 2-3" deep. Each section produces new plant.
- Special notes: Germination slow and erratic (21-35 days). Seeds benefit from cold stratification (32-40°F for 2-4 weeks). Scarification (nick seed coat) helps. Plants bolt to flower in summer—remove flower stalks if focusing on leaf/shot production. Blanching is traditional but optional; unblanched shoots can be used in cooked dishes.
📖 Sources Consulted
- Royal Horticultural Society. "Crambe maritima (Sea Kale)." RHS Plant Database, 2024.
- Monticello/Digital Archaeological Archive of Thomas Jefferson. "Sea Kale." Thomas Jefferson Foundation, 2023.
- Toxopeus, H., et al. "Sea Kale (Crambe maritima L.): A Forgotten Vegetable Crop." Genetic Resources and Crop Evolution, vol. 53, 2006, pp. 669-683.
- Ashworth, Suzanne. Seed to Seed: Seed Saving and Growing Techniques for Vegetable Gardeners. 2nd ed., Seed Savers Exchange, 2002.
- Wright, Jason. "Sea Kale: The Victorian Vegetable Worth Reviving." The Garden, vol. 142, no. 8, 2017, pp. 56-59.
Added to WV Planting Guide 26155 — The Loop Farmstead