Crop type: Kale
Brassica oleracea (Acephala Group) ‘Starbor’ AGM
Common name: Borecole ‘Starbor’ AGM
Crop slug: kale
This Allotment Pro editorial draft summarises the cited RHS cultivar profile. Check the source and adjust cultivation decisions for local conditions.RHS cultivar profile
1 - Overview
‘Starbor’ is a compact curly kale forming a dense clump around 40–45cm tall and about 45cm wide. Its tightly packed leaves are densely curled and blue-green, creating a low rounded crown suited to small plots and containers. The cultivar is very winter hardy and can supply mature leaves over a long season or baby leaves from protected container sowings.
The low, nearly equal height and width, dense blue-green foliage and tightly curled texture distinguish ‘Starbor’ from tall open borecoles. The RHS profile displays an Award of Garden Merit.
2 - Size
- Ultimate height
- 0.1–0.5 metre; usually around 40–45cm
- Ultimate spread
- 0.1–0.5 metre; usually around 45cm
- Time to ultimate size
- 1 year
The compact rounded plant is appropriate where full-sized kale would dominate. Allow enough room for its 45cm crown and keep neighbouring foliage clear so the dense centre receives air.
3 - Growing conditions
- Suitable soils
- Chalk, clay, loam or sand
- Moisture
- Moist but well-drained or well-drained
- Soil pH
- Neutral or alkaline
‘Starbor’ accepts a wide range of soil textures but prefers drainage and non-acid conditions. Add organic matter before planting, water in dry weather and mulch mature plants to conserve moisture.
4 - Position and hardiness
- Light
- Full sun or partial shade
- Aspect
- North-, south-, east- or west-facing
- Exposure
- Exposed or sheltered
- Hardiness
- H5 — hardy in most UK places even through severe winters
This adaptable compact cultivar can grow in sun or light shade and in exposed or protected positions. Its H5 rating enables winter cropping, while the low crown is less vulnerable to wind-rock than tall kale.
5 - Colour and seasonal interest
The foliage remains blue-green through spring, summer, autumn and winter. Every leaf is densely curled, and the overlapping blades make a tight rounded crown with little visible stem. The cool glaucous colour and compact ball-like silhouette are the principal cultivar identifiers.
6 - Botanical details
- Family
- Brassicaceae
- Native to Great Britain and Ireland
- No
- Foliage
- Deciduous
- Habit
- Clump forming
- Name status
- Accepted
Genus
Brassicas may be annual, biennial or perennial. Most are upright with alternate, often glaucous leaves, long taproots and clusters of cross-shaped yellow or white flowers. Many members have been bred as vegetables.
Safety
No specific handling warning is listed on the exact RHS profile. Wash the compact densely curled crown carefully after picking, checking folds for insects or soil.
7 - How to grow
Cultivation
Grow in well-drained neutral or alkaline soil and add mulch around established plants. Water regularly in dry periods. Sow in spring and transplant firmly, or grow in a container at least 30cm wide and deep. The compact habit suits one mature plant per large pot and can also provide baby leaves under protection.
Harvest young leaves from the main crown from mid-autumn onwards, leaving the central growing point intact. Pick side shoots from mid-winter until late spring. The very winter-hardy foliage can support a prolonged or nearly year-round harvest where conditions allow.
Propagation
Propagate by seed. Sow approximately 1cm deep, thin to one strong seedling and transplant without disturbing the root ball.
Suggested locations
- Small vegetable plot
- Patio or container planting
- Exposed winter bed
- Compact edible border
Pruning
Remove young crown leaves from mid-autumn and harvest side shoots from mid-winter to late spring. Clear yellowing or damaged leaves as needed.
Pests
May be susceptible to caterpillars, cabbage whitefly, aphids, flea beetles, slugs and snails.
Diseases
May be susceptible to black rot, downy mildew, foot and root rot, grey mould, leaf spot and white blister. Good drainage and airflow around the compact crown are important.