Crop type: Pak Choi
Brassica rapa (Chinensis Group) ‘Glacier’
Common name: Pak choi ‘Glacier’
Crop slug: pak-choi
This Allotment Pro editorial draft summarises the cited RHS cultivar profile and its linked crop guidance. Check the sources and adjust cultivation decisions for local conditions.RHS cultivar profile
1 - Overview
‘Glacier’ is an AGM pak choi bred in Britain to suit British weather. It is slower to bolt than many varieties, tolerates cold and has a long cropping season. Broad white stems support deep-green leaves, forming substantial crisp heads for cooking as well as useful young salad foliage.
Its combination of hot-weather bolting resistance and cold tolerance makes it especially versatile for spring, summer and autumn sowings. Even so, steady moisture and prompt harvesting remain important.
2 - Size
- Ultimate height
- 0.1–0.5 metre
- Ultimate spread
- 0.1–0.5 metre
- Time to ultimate size
- one year
Allow 8–10cm for baby leaves, 20cm for semi-mature plants and 25–30cm for full heads. Mature plants normally reach about 30–45cm tall.
3 - Growing conditions
- Suitable soils
- Chalk, clay, loam or sand
- Moisture
- Moist but well drained
- Preferred pH
- Acid, neutral or alkaline
Grow in fertile soil enriched with well-rotted organic matter. Maintain moisture throughout growth so the broad stems stay succulent, while avoiding waterlogging around the base.
4 - Position and hardiness
- Light
- Full sun; light shade is useful in hot summer weather
- Aspect
- North-, south-, east- or west-facing
- Exposure
- Exposed or sheltered where moisture can be maintained
- Hardiness
- H3
The cultivar's cold tolerance suits early and late crops, although fleece or cloches still protect seedlings from severe checks. Summer shade further supports its resistance to bolting.
5 - Colour and seasonal interest
A tight columnar rosette combines broad bright-white succulent stems with large deep-green leaves. This strong colour contrast distinguishes ‘Glacier’ from green-stemmed cultivars. Harvest before yellow flower buds develop.
6 - Botanical details
- Family
- Brassicaceae
- Native to Great Britain and Ireland
- No
- Foliage
- Deciduous
- Habit
- Columnar upright
- Name status
- Unresolved
- Synonym
- Brassica rapa (Chinensis Group) ‘Tz 9230’
Genus
Brassica includes upright annual, biennial and perennial plants with alternate leaves, long taproots and clusters of cross-shaped yellow or white flowers. Many members are cultivated as vegetables.
Safety
The leaves and broad white stems are edible. Wash young salad leaves carefully and lightly cook mature heads to retain their crisp texture.
7 - How to grow
Cultivation
Sow from spring onwards, one or two seeds per module or outdoors in drills 2cm deep. Thin gradually according to harvest size. Sow small batches every few weeks to use the cultivar's long cropping season.
Water in dry weather, mulch full-sized crops and use light shade in summer. Baby leaves may be ready in 30 days and compact heads in 45–75 days. Cut mature plants at the base with a sharp knife.
Propagation
Propagate by seed.
Suggested locations
- Vegetable plot
- Raised bed
- Patio container
- Growing bag
- Unheated greenhouse
Pruning
No pruning is required. Remove a flower stem before buds open and harvest the plant promptly.
Pests
May be susceptible to flea beetle, cabbage caterpillars, slugs, snails and pigeons. Fine mesh protects pristine foliage.
Diseases
May be susceptible to powdery mildews. Maintain airflow and consistent moisture and rotate brassica crops.