Allium porrum
leek
Leeks are herbaceous perennials usually grown as annual vegetables, with upright stems which can be blanched white, and green or blue-green leaves about 30-50cm long; plants may flower by bolting in their first year, or the following year if left to overwinter, with stems up to 1.5m high topped by rounded flowerheads 5-9cm across of hundreds of star-like pale pink to white flowers which are visited by bees, in summer
Size
Ultimate height
0.1–0.5 metresTime to ultimate height
1–2 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green White | |||
|---|---|---|---|---|
| Summer | Pink White | Green White | ||
| Autumn | Green White | |||
| Winter | Green White |
Position
- Full sun
- Partial shade
Aspect
East–facing or South–facing or West–facing
Exposure
Exposed or Sheltered Hardiness
H4Botanical details
- Family
- Amaryllidaceae
- Native to GB / Ireland
- No
- Foliage
- Evergreen
- Habit
- Clump forming
- 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
Correct
How to grow
Cultivation
Sow seed, under cover in late winter or early spring or outside in late spring, about 1cm deep in moist but well-drained soil that is rich in organic matter, preferably in full sun though they will tolerate partial shade; thin seedlings to 15cm apart, or, to get the classic white stems, lift and re-plant seedlings from spring to early summer in holes 15cm deep at 15cm spacings, and harvest from late summer or early autumn to winter; for more advice, see leek cultivation
Propagation
Propagate by seed. See sowing vegetable seeds
Suggested planting locations and garden types
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, onion white rot, downy mildews, foot and root rots, fungal leaf spots, and smuts
Get involved
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.