Common Name: Egyption tree onion
Type: Herbaceous perennial
Family: Amaryllidaceae
Native Range: Garden origin
Zone: 3 to 9
Height: 2.00 to 3.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: May to June
Bloom Description: White
Sun: Full sun
Water: Medium
Maintenance: Medium
Suggested Use: Vegetable
Flower: Insignificant
Tolerate: Rabbit, Deer, Black Walnut
Culture
Best grown in evenly moist, deep, well-draining, rich sandy-loams in full sun. Hardy in Zones 3-9. Propagate through bulbils or division of clumps. The spreading nature of this plant is not considered aggressive, but regular harvesting of bulbils will help reduce any unwanted spread.
Noteworthy Characteristics
Allium × proliferum, commonly called Egyptian tree onion, topset onion, or walking onion, is a hybrid, herbaceous, perennial, domesticated onion believed to be a cross between Allium fistulosum and A. cepa. The subterranean bulbs are relatively small and shallot-like in appearance, reaching around 1.5" wide with a purplish-red skin. Clumps of 2-3' tall and 1.25" wide, hollow leaves emerge from the bulbs in spring. In late spring a stalk emerges above the foliage called a topset that bears a cluster of miniature bulbs called bulbils or bulblets. The bulbils can reach 0.25-1" wide. Small, white flowers are occasionally produced in the topset, but are not believed to produce viable seeds. As the season progresses and the bulbils grow larger, the topset will nod to the ground where the bulbils will root and create a new clump. Mature clumps will reach 1-2' wide but can spread to fill a much larger area through the spreading bulbils. Synonymous with Allium cepa var. proliferum
Genus name comes from the classical Latin name for garlic.
The hybrid name proliferum means "having bunching growth or offsets" and refers to the abundant bulbils produced by this plant.
The common names of this species all various refer to its ability to reproduce through abundant bulbils. The "Egyptian" moniker often applied to this plant is of unknown origin.
Problems
Onions are susceptible to number of pests and diseases. Diseases include botrytis, purple blotch, downy mildew, neck rot, soft rot, onion smut and viruses such as onion yellow dwarf and iris yellow spot. Common pests include onion thrips, allium leaf miner and onion fly (also known as onion maggot). Rot is more likely in poorly drained, overly moist soils. Deer and rabbits tend to avoid this plant.
Uses
All parts of this plant are edible. The bulbils and leaves can be eaten raw or cooked. The bulbils store well if cured properly and can be pickled with cucumbers or other vegetables to add an onion flavor. The bulbs can also be eaten raw or cooked but have a quite strong, spicy flavor. Young, first year plants can be used as scallions. The bulb skins can be used to obtain a yellow-brown dye.