Egyptian Walking Onions (EWO) (Allium x proliferum) are a perennial onion resulting from a cross between a common onion and a Welsh onion. They are red to white in color and are thought to have originated in India or Pakistan. The EWO gets its name for the way it spreads or “walks” through the garden. Common onions produce a flower stalk which is where the seeds are produced. EWOs produce topsets or clusters of bulblils which will fall over as their size increases (if not harvested) and will root where they hit the ground. This is how they “walk” through the garden.
EWO, also called Tree Onions, Perennial Onions, Winter Onions or Topset Onions, are very hardy, to -24°F and will grow in USDA zones 3-10. The onions can grow to the size of a shallot but are more pungent and spicy.
Plant in well-drained soil, that is high in organic matter and a pH between 6.2-6.8, or fairly neutral. If soil does not drain well, plant in raised beds, hills or containers.
Space bulbs about 10-12 inches apart and rows 2’ apart.
Incompatibility — asparagus, beans, peas, cabbage, turnips, squash, cucumbers or melons.
Companions — marigold, fennel, carrots, tomato, potato, peppers, okra.
Requires even moisture for good yields, so it will be essential to mulch in the summer and if natural rains are absent, drip irrigation will need to be in place. EWO can fail if they are allowed to grow in soggy, wet conditions.
EWO do not require heavy fertilization, a good organic all-purpose fertilizer is a good choice.
Keep well weeded, does not compete well with weeds.
Plant in full sun, but will tolerate some partial shade. Note: EWO are tolerant to juglone and therefore can be planted under or near a walnut tree or where one was grown prior.
Planting & Growing
Plant in a dedicated bed, since they are perennials or put a in container. Individual bulbs or clumps can be planted about 1-2” deep, in well-drained soil, in full sun to part shade. Space bulbs about 10-12 inches apart and rows 1-2’ apart. Fall is the optimal planting time. Mulch with 4-8 inches of straw, making sure to remove or reduce thickness in spring.
Development of Topsets
A dominant stock will develop and a cluster of bulblets or bulbils, form at the top, thus the name Topsets. This stage is called the Candlestick Stage. Topsets are enclosed in a white papery skin. The topsets can breakthrough the papery skin as they grow and develop leaves. Note: Not all plants will develop topsets during their first year of growth.
Topsets can be removed and planted or allowed to continue to develop on the stalk. The topsets reach maturity in the late summer. Some may develop a second stalk and develop a cluster on top. If you want bigger bulbs to develop (cluster in the ground), then remove the topsets. Flowers can develop among the topsets, especially on older plants or on crowded plants. When the topsets get heavy, their stalk will bend over and if the soil conditions are right, the topset can develop roots and grow into new plants.
EWO are similar to a shallot but a bit more pungent and spicy. Yield is light the first year. Second year it will be much larger. Topsets can be harvested and eaten or planted for next year’s plants. The clump of onions that develop are similar size to shallots. To get the largest bulb size, cut off the topsets as they begin to develop. One plant can develop up to 6 onions or 6 new plants, if divided. Harvest fall through winter. If you do not harvest your onions, they will grow back the following year, producing an even larger clump. When harvesting, make sure to leave some in the ground to continue growing or save some for replanting.
The green leaves can be harvested the second year and used as scallions, making sure not to remove the topset stalk.
After cutting, allow the bulbs to dry out of the sun in a well-ventilated location. This allows the outer skins of the onions to dry and will help increase storage life. Store in a cool, dark and dry location. If the conditions are proper, bulbs will store for months.
Your EWO will spread if you do not harvest your topsets. To move your EWO to another location or share with a friend, just break off the topset and plant. The main clump of bulbs can also be dug and divided. Best time to divide your EWO clumps is the spring or fall. If your mother plant becomes overgrown it is a good idea to divide it, about every 3 years, or sooner if you see a decrease in topset formation. Clumps can be lifted with a garden fork, taking care not to get too close to the EWO as this may damage the bulbs.
Common Pests & Diseases
Onion Fly: usually a problem during very wet growing seasons. Control with a product labeled for onion flies (or maggots).
Onion Thrips: Can control with insecticidal soap.
Slugs: Control by either hand picking or use a product labeled to control slugs.
Gophers: plant in gopher baskets or line your raised bed with gopher wire.
Bacterial soft rot: treat accordingly. Here is a good resource for treatment.
Botrytis blight: for more information on treatment, visit the UCIPM website.
Pest Control – IPM
Important to practice good cultural controls for pest management of EWO. Cultural controls such as removing plants after harvest (to avoid leaving food for insects to continue to multiply on), use healthy bulbs to plant.