Allium porrum 'Mammoth Pot Leek'

RHS Plant Profile
leek 'Mammoth Pot Leek'

Synonyms

Allium porrum 'Mammoth Pot'

Award of Garden Merit
Herbaceous Perennial

A large, hardy perennial usually grown as an annual vegetable, with thick, semi-upright, mid-green leaves and short, blanched stems. Bred for exhibition purposes due to the heavy leeks it produces, but has a good flavour and tight flesh, making it a great addition to stews, soups and other culinary uses. Sow from January to April for harvesting from September to January

Position

Full sun, Partial shade

Soil Types

Chalk, Clay, Loam, Sand

Size

Time to Maturity
1 year

Growing Conditions

Chalk Clay Loam Sand
Moisture
Moist but well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun Partial shade
Aspect
South–facing or West–facing
Exposure
Exposed or Sheltered
Hardiness
H5

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Amaryllidaceae
Native to GB/Ireland
No
Foliage
Evergreen
Habit
Columnar upright
Genus
Allium are bulbous herbaceous perennials with a strong onion or garlic scent, linear, strap-shaped or cylindrical basal leaves and star-shaped or bell-shaped flowers in an umbel on a leafless stem
Name Status
Accepted

How to Grow

Cultivation

Grow in moist but well-drained soil that is rich in organic matter, preferably in full sun though they will tolerate partial shade. For longer blanched stems, draw up soil around the stems in late summer and early autumn. See leek cultivation for further advice

Propagation

Propagate by seed. See sowing vegetable seeds

Pruning

No pruning required

Pests

May be susceptible to slugs and snails, leek moth, onion fly, and onion thrips

Diseases

May be susceptible to leek rust, although this variety shows some resistance, onion white rot, downy mildews, foot and root rots, fungal leaf spots, and smuts