Allium porrum (Swiss Giant Group) 'Jolant'
leek 'Jolant' (Swiss Giant group)
A vigorous variety with mid-green to dark green leaves and gives a high yield with a long harvest season from late summer until early winter of stems up to 30cm long and 4cm across, with very little tendency to bolt. Leeks, Allium porrum, 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 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.
Buy this plant
Size
Ultimate height
0.5–1 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 | |||
|---|---|---|---|---|
| Summer | Pink White | Green | ||
| Autumn | Green | |||
| Winter | Green |
Position
- Full sun
- Partial shade
Aspect
South–facing or West–facing or East–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
Accepted
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 sown under cover in late winter, or outside in late spring or early summer
Suggested planting locations and garden types
Pruning
No pruning required
Pests
Maybe susceptible to slugs and snails, leek moth, onion fly, and onion thrips
Diseases
Leeks may be affected by leek rust, onion white rot, downy mildews, foot and root rots, fungal leaf spots, and smuts; 'Jolant' is said to be less susceptible than other cultivars to leek rust
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.