Agriculture Reference
In-Depth Information
PEARL ONION
Allium ampeloprasum
var.
sectivum
Pearl onions are a winter-hardy variant of leeks. They develop numerous small bulbils in the root zone
with white to silvery scales. They have no brown outer peel like onions and look like pearls. Pearl
onions are mainly grown in a narrow band from Italy through Austria and Germany to the Nether-
lands, and even in this swath they are mostly a crop for home gardeners. Commercial production is
mainly for pickled pearl onions (and it is worth noting that most “pearl onions” from supermarkets are
actually small, white common onions that are grown in dense patches and harvested early). Pearl
onions are excellent stewed, for refining sauces, or, thanks to their mild yet spicy flavor, raw in salads.
Leaves can be harvested for green onions.
WHAT YOU'LL NEED
• five healthy plants
POLLINATION NOTES
Pearl onions cross with leeks. Plants can produce seed but not reliably every
year.
PROPAGATION
Vegetative propagation is the norm for pearl onions and easily accomplished. Plant
bulbs in late summer 4 in. (10 cm) apart, 1-1.5 in. (3-4 cm) deep. They love humus-rich, sandy soils.
Plants do not need much space, and most varieties grow to be 12 in. (30 cm) tall, though some can
grow up to 24 in. (60 cm) tall. Bulbils develop as days grow longer and can be harvested as soon as
leaves die back. When bulbils are left longer in the ground, they separate from one another, which
makes harvesting more difficult. Unearth with a digging fork and select by hand: larger pearl onions
for the kitchen, smaller ones for further propagation. The bulbils do not store well and must either be
eaten, replanted, or pickled right away. When plants are left in the ground for another year, the yield is
greater.
SELECTION CHARACTERISTICS
• vigorous growth
• yield
• plant health
DISEASES AND PESTS
Diseases and pests are the same as for the leek, but these are rare for pearl
onions, as the vegetative period is relatively short.
