Winter Onions - 6 Month Update

In November we planted winter onions for the first time. Winter Onions are also referred to as “Egyptian Walking Onions”, “Egyptian Tree Onions”, “Tree Onions”, “Walking Onions”, “Top Onions”, and “Perennial Onions”.

The blue-green shoots/stalks/leaves are round and hollow and typically grow approximately 3 feet tall. As the plant matures a cluster of bulblets will begin to grow at the top of the stalk encapsulated in a protective papery casing referred to as a tunic.

As the bulblets grow they will burst through the papery capsule. Like the onion, the bulblets are referred to in various ways such as “bulbils”, “sets”, “bulbs”, and “topsets”. This cluster of bulblets/sets are produced at the top of the onion shoot thus the name “Top Onion”.

Comparison of Annual Onion Sets (Far Left) Planted in Feb to Winter Onions (Right) Planted in Nov.

Typically, during their first year of growth the onions will not produce topsets. Don’t be surprised if you only see greens the first year, but they will grow back the following year with a vengeance and produce its topsets. However, you can see in the picture above ours have done very well and have been in the ground since November for 6 months now. Luckily, we do have topsets on our first year! Topsets produced by winter onions are usually a bit smaller than the average annual variety onion sets. They may vary in size from 1/4 inch to 1 inch in diameter with each cluster with as few as 2 or up to 30 (usually a well established plant) topsets. Occasionally a new stalk with shoot from a cluster of topsets similar to a tree branch and a second cluster will begin to grow. This is where the name, “Tree Onion”, is derived.

If the topset are not gathered, the weight of them will eventually bend the onion stalk down and it will establish roots and plant itself where the topset takes hold in the ground. Thus the name “Walking Onions”.

If the onion in the ground is harvested to eat the plant will not grow back. Be sure to replant the topsets to keep a perpetual supply. Similar to hostas the winter onion may also propagate by division if the onion bulb is left in the ground. This cluster of full size onion bulbs can also be divided and replanted or harvested.