Also called Tree Onion or Egyptian Onion. An old hybrid between ordinary onions (A. cepa) and Welsh onions (A. fistulosum). At the to of the 60-80 cm tall stalks it forms a bunch of small onions instead of flowers. There may appear flowers too, but these are sterile. Often the bunches of small onions are formed in several stories of bunches with pieces of stalk in between.
You can eat the whole plant but usually only the top onions are eaten, or fresh leaves in spring.
In the autumn the plant withers and only the onion in the ground remains. It is fully winter hardy and survives at least -25 °C.
This species is propagated either by setting some top onions, or by dividing the clump of onions in the ground. The top onions can be planted at any time except when the ground is frozen.
The top onions should be harvested before the stalk falls over and they land on the soil, since they will start forming roots then.