Agriculture Reference
In-Depth Information
The underground bulbils of the leek
CULTIVATION HISTORY
The highly variable wild form of leek occurs in Portugal, northern Africa,
and from Turkey to Iran, growing in undisturbed soils, coastal cliffs, and sandy beaches. The cultiv-
ated leek is an ancient garden vegetable that has been grown in the eastern Mediterranean region for
4,000 years. Leeks are mainly grown in North America and western Europe; many old and interesting
varieties are to be found in the UK and France.
Digging deeper
One special feature of
Allium ampeloprasum
var.
porrum
is unknown to many, as it is hidden
underground. When plants overwinter outdoors, they form underground bulbils, or pips. These
can be used to vegetatively propagate leeks.
Bulbil growth can be encouraged by pruning flowers before they open, which stimulates a di-
vision in the growth zone at the base of the plant. In this way, two to five independent bulbils
form, which can then be separated from the mother plant. Because they have no protective outer
leaves, they must either be replanted or stored in sand. Bulbils are genetically identical to moth-
er plants and can be used to maintain varietal purity. Switzerland's Pro Specie Rara uses this
trait to its advantage when two or more varieties are near each other in the display garden but
only one should flower.
Bulbils are harvested in summer. If they are not needed or wanted for propagation, they
should be eaten, as they are a delicacy—much milder than onions, almost reminiscent of radish
in flavor. Simply slice up and eat on buttered wholegrain sourdough bread for a quick and de-
lectable evening meal from the garden.
