Crop type: Broccoli

Brassica oleracea (Italica Group) 'Red Admiral'

Common name: broccoli (purple sprouting) 'Red Admiral'

Crop slug: broccoli

This Allotment Pro editorial draft summarises the cited RHS cultivar profile.

1 - Overview

'Red Admiral' is an upright, branching purple-sprouting broccoli grown as an annual or biennial. Its evergreen, bushy plant carries oblong, wavy-edged blue-green leaves. Numerous side-shoots develop edible spears topped with purple-flushed buds, which are harvested from autumn through spring.

The profile highlights the uniform spears for their good flavour and texture. A plant can continue cropping for up to two months, and the parent guide notes that this vigorous cultivar may begin as early as November.

2 - Size

Ultimate height: 0.5–1m
Ultimate spread: 0.1–0.5m
Time to ultimate size: 1–2 years

3 - Growing conditions

Suitable soils: Chalk, clay, loam and sand
Moisture: Moist but well-drained
Soil pH: Alkaline or neutral

4 - Position and hardiness

Light: Full sun
Aspect: South-facing or west-facing
Exposure: Exposed or sheltered
Hardiness: H4 — hardy through most of the UK, tolerating the RHS winter temperature band of about -10 to -5°C

5 - Colour and seasonal interest

Season	Flowers	Foliage	Fruit
Spring	Green and purple	Blue-green	—
Summer	—	Blue-green	—
Autumn	Green and purple	Blue-green	—
Winter	Green and purple	Blue-green	—

The green-and-purple flower entries correspond to the flushed buds on the edible spears. Cut them while tightly budded rather than allowing the flowers to open.

6 - Botanical details

Family: Brassicaceae
Native to Great Britain and Ireland: No
Foliage: Evergreen
Habit: Bushy
Name status: Unresolved

Genus

Brassicas can be annual, biennial or perennial and are commonly upright, with alternate, often glaucous foliage, long taproots and clusters of cross-shaped yellow or white flowers. The genus includes broccoli, cabbages, turnips, mustards, oilseed rape and ornamental forms.

7 - How to grow

Cultivation

Grow 'Red Admiral' in fertile soil in full sun. Its profile accepts both exposed and sheltered positions, but supporting a tall, productive plant helps prevent wind-rock. Maintain even moisture in freely drained ground and use the parent broccoli guide for detailed sowing, spacing, transplanting and harvest advice.

Rotate this brassica with unrelated crops. Protect the blue-green foliage and purple-flushed spears with fine mesh so the plant can sustain its long autumn-to-spring cropping period.

Propagation

Propagate by seed, using either an indoor start or the appropriate outdoor vegetable-seed method.

Pruning

No pruning is required. Cut each edible spear while the buds remain tight; harvesting the central shoot and later side-shoots supports the profile's potential cropping period of up to two months.

Pests

The profile lists possible damage from birds and caterpillars. A securely fitted fine-mesh cover helps exclude both while allowing the branching crop to develop.

Diseases

The profile lists susceptibility to club root. Use crop rotation and healthy transplants, avoid moving contaminated soil, and provide free drainage; on affected ground, strong indoor-raised root systems can reduce the severity of damage.