Austurian Tree Cabbage - Care Sheet
Overview
Asturian Tree Cabbage (Brassica oleracea var. acephala) is a hardy perennial brassica from northern Spain, forming a tall woody stem topped with huge, tender emerald-green leaves that taste like mild, sweet cabbage. Ideal for cool, damp climates like Scotland, it provides repeated harvests of versatile greens for soups, stir-fries, or salads, thriving for years with regular pruning to prevent flowering and encourage bushy regrowth.
Quick Facts
| Scientific name | Brassica oleracea var. acephala |
|---|---|
| Common name | Asturian Tree Cabbage |
| Difficulty | Beginner |
| Pet-safe? | Unknown (Brassica family; leaves edible for humans but monitor pets for digestive upset) |
| Light | Full sun (tolerates light shade) |
| Water | Moist, well-drained (regular during dry spells) |
| Humidity | Normal (prefers damp conditions) |
| Temperature | 0–20°C / 32–68°F (frost hardy to -8°C / 18°F) |
| Soil | Fertile, moisture-retentive, pH 6.5–7.5 |
| Fertilizer | Spring feed (liquid seaweed or compost) |
| Repotting | Every 2–3 years (or replace mature plants) |
| Propagation | Stem cuttings (roots in 6 weeks) |
Light
Give your Asturian Tree Cabbage full sun for the best compact growth and leaf production—aim for at least 6 hours of direct sunlight daily. It tolerates light partial shade, especially in windy spots, but too much shade can lead to leggy growth and higher disease risk. In cooler climates, a sunny, sheltered border keeps it thriving year-round.
Water
Keep soil consistently moist but never waterlogged, watering deeply once a week during dry spells (about 3–4 cm / 1.5 inches per session). Young plants need regular moisture to establish roots, while established ones are more drought-tolerant. Mulch around the base with compost or leaves to retain moisture and suppress weeds, especially in lighter soils.
Humidity
Normal ambient humidity suits this plant well, as it loves cool, damp conditions like those in Scotland. High humidity from coastal areas is fine, but ensure good airflow to prevent fungal issues in stagnant, wet weather. No need for misting—outdoor growing provides ideal levels.
Temperature
Frost-hardy to around -8°C (18°F), it handles Scottish winters beautifully and stays productive through mild summers up to 20°C (68°F). Protect young plants from harsh frosts during establishment, but mature specimens shrug off cold snaps. Avoid extreme heat above 25°C (77°F), which can slow growth.
Soil & Potting
Plant in fertile, well-drained soil rich in organic matter, with a pH of 6.5–7.5 for optimal nutrient uptake. Amend heavy clay with compost for better drainage, and avoid waterlogged spots in winter. Space plants 60–90 cm (2–3 ft) apart in raised beds, food forests, or borders. For pots, use a deep container (at least 45 cm / 18 inches) with multipurpose compost mixed with added organic matter.
Feeding
Feed in early spring with liquid seaweed, compost tea, or well-rotted manure to boost leafy growth. Annual mulching replenishes nutrients naturally. As a heavy feeder like other brassicas, it benefits from nitrogen-rich amendments, but skip summer feeds to avoid soft growth prone to pests.
Repotting
Repot young plants every 2–3 years in spring into larger containers (increase by 5–10 cm / 2–4 inches), refreshing soil with compost. Mature outdoor plants rarely need repotting—simply replace old specimens after 5–7 years or propagate new ones. Cut back tall stems first to manage size.
Propagation
Propagate easily from stem cuttings: snip a side shoot with a growing tip (10–15 cm / 4–6 inches long) in spring or summer, pot in moist peat-free compost, and roots form in about 6 weeks. Plant out after hardening off. Seeds are possible but often don't grow true; cuttings ensure reliable perennial traits. Spring (April–June) or early autumn (September) planting works best in cool climates.
Common Problems
Cabbage White Caterpillars
Butterfly eggs lead to voracious larvae—net plants from spring to autumn and hand-pick eggs. Companion plant with garlic or onions to deter them naturally.
Fungal Diseases (e.g., Downy Mildew)
Damp, shaded spots cause yellowing leaves—improve airflow, space properly, and avoid overhead watering. Remove affected foliage promptly.
Leggy or Tall Growth
Insufficient light or no pruning makes plants top-heavy—cut back main stem in spring to promote bushy side shoots.
Pest Resistance Low (Aphids/Whitefly)
Clusters on new growth—blast with water or introduce ladybugs. Good natural caterpillar resistance helps overall.
Winter Root Rot
Waterlogging weakens roots—ensure drainage and mulch slopes to prevent saturation during wet winters.
Toxicity & Pet Safety
Unknown for pets—while leaves are safe and nutritious for humans (like kale or cabbage), brassicas can cause digestive upset in large amounts for dogs or cats due to compounds like glucosinolates. Keep away from grazing livestock unless intended as forage; monitor pets and consult a vet if ingestion occurs.
Seasonal Care
Spring: Cut back flowering stems to restart leaf production; feed and propagate. Summer: Harvest outer leaves regularly, net against pests, water in dry spells. Autumn: Plant new cuttings, mulch for winter. Winter: Minimal care—leaves stay harvestable in mild weather; remove damaged foliage.
Quick Tips
- Harvest lower leaves often to keep plants bushy and productive for 5+ years.
- Space 80 cm–1 m (2.5–3 ft) apart for airflow and mature size.
- Prevent flowering by snipping buds yearly—prolongs life dramatically.
- Pair with legumes or alliums for natural pest control and soil health.
- Mulch annually with compost to maintain moisture and fertility.
- Sunny, sheltered spots yield the tastiest, largest dinner-plate leaves.
- Young shoots are a delicacy—pick for tender, broccoli-like flavor.