Allium ampeloprasum is a very variable species and has been treated in various ways in the past, with many subspecies and vars being recognized. Current classification in the 'World Checklist of Selected Plant Families' (2016), treats it as one variable species, but does not recognize any subspecies or vars, Instead, it recognizes different cultivated groups of plants and, since all of these different forms, including the various cultivated forms, intergrade into each other, we are following this treatment here. We are, however, also including Babbington's Leek (Allium ampeloprasum babbingtonii) here as a separate subspecies since it is clearly distinct in its production of bulbils and therefore has a somewhat different range of uses[].

Common Name: Leek

General Information

Allium ampeloprasum Leek Group is a herbaceous, perennial plant, usually cultivated as a biennial, producing a pseudostem of leaves 50 - 70cm long and a flowering scape 60 - 80cm tall. The bulb of this form is much reduced[].
The leek is often cultivated as a winter vegetable in the temperate zone, both on a garden scale and also commercially.

Known Hazards

Although no individual reports regarding this species have been seen, there have been cases of poisoning caused by the consumption, in large quantities and by some mammals, of certain members of this genus. Dogs seem to be particularly susceptible[].

Botanical References

Range

A cultivated form of the wild leek (Allium ampeloprasum), not known as a wild plant

Habitat

Not known in the wild.

Properties

Edibility Rating
Medicinal Rating
Habit	Bulb
Height	0.90 m
Pollinators	Bees, Insects
Cultivation Status	Cultivated

Cultivation Details

Prefers a sunny position in a light well-drained soil[] but succeeds in most soils[]. Grows well in heavy clay soils. Prefers an open situation[, ]. Does best in a soil that was well fed for a previous crop[]. Tolerates a pH in the range 5.2 to 8.3.
The leek is a widely cultivated vegetable, there are many named varieties[]. Young plants are often planted quite deeply in the soil (8 - 10cm deep) in order to blanch the lower stem, it is also a common practice to earth up the growing plants in order to blanch right the way up the stems. Whilst this does make the stems more tender, it also results in a loss of minerals and vitamins.
Although commonly treated as a biennial, this plant is a true perennial, perennating by means of small lateral growths and often developing a roundish bulb at the base of the main growth[].
A relatively slow-growing plant, it can be interplanted in early summer with faster maturing species such as lettuces[].
The bulbs should be planted fairly deeply[].

Edible Uses

The leaves and long white blanched stem are eaten cooked[, , , ]. They can also be cut into thin slices and be added to salads[]. A mild onion flavour with a delightful sweetness[, ].

Bulb - raw or cooked. The bulb is produced in the plants second year of growth (that is, after it is normally harvested). The bulb is somewhat larger if the plant is prevented from flowering[].

Flowers - raw. Used as a garnish on salads, though they are rather on the dry side and less pleasant than many other members of the genus[].

Medicinal

This species has the same medicinal virtues as garlic, but in a much milder and less effective form[]. These virtues are as follows:-

Garlic has a very long folk history of use in a wide range of ailments, particularly ailments such as ringworm, Candida and vaginitis where its fungicidal, antiseptic, tonic and parasiticidal properties have proved of benefit[]. The plant produces inhibitory effects on gram-negative germs of the typhoid-paratyphoid-enteritis group, indeed it possesses outstanding germicidal properties[] and can keep amoebic dysentery at bay[]. It is also said to have anticancer activity[]. It has also been shown that garlic aids detoxification of chronic lead poisoning[]. Daily use of garlic in the diet has been shown to have a very beneficial effect on the body, especially the blood system and the heart. For example, demographic studies suggest that garlic is responsible for the low incidence of arteriosclerosis in areas of Italy and Spain where consumption of the bulb is heavy[]. Recent research has also indicated that garlic reduces glucose metabolism in diabetics, slows the development of arteriosclerosis and lowers the risk of further heart attacks in myocardial infarct patients[, ]. Externally, the expressed juice is an excellent antiseptic for treating wounds[].
The fresh bulb is much more effective medicinally than stored bulbs, extended storage greatly reduces the anti-bacterial action[].
The bulb is said to be anthelmintic, antiasthmatic, anticholesterolemic, antiseptic, antispasmodic, cholagogue, diaphoretic, diuretic, expectorant, febrifuge, stimulant, stings, stomachic, tonic, vasodilator[, , , , , ].

Agroforestry Uses:

Allium species usually grow well with most plants, especially roses, carrots, beet and chamomile, but they inhibit the growth of legumes[, , ]. They are, in general, bad companions for alfalfa - each species negatively affecting the other[].
Members of this genus are rarely if ever troubled by browsing deer[].

Other Uses

Although no specific mention has been seen for this species, the juice of most species in this genus (especially those with a strong onion or garlic smell) can be used as a moth repellent[].
The whole plant is said to repel insects and moles[].

Propagation

Seed - for an early crop, or for larger plants, sow the seed in early spring in a greenhouse and plant out in May. For smaller or later plants, sow mid spring in an outdoor seedbed and plant out as space permits in mid to late summer.