The Egyptian Walking Onion (Allium proliferum) is a unique perennial plant that provides harvests across multiple seasons. Unlike common bulb onions, this variety produces small bulb clusters called topsets, or bulbils, atop its stalks. These bulbils cause the plant to “walk” as they eventually bend down and root. The plant offers several edible components, including greens, scapes, bulbils, and underground bulbs, requiring an understanding of the different developmental stages for proper harvesting.
Harvesting the Greens and Scapes
The leaves provide a continuous supply of mild green onions throughout the growing season, starting in early spring and continuing through the summer. To ensure sustained vigor, cut only the outer leaves cleanly near the base, about an inch above the soil line. This leaves the central growing point intact, allowing the plant to produce new foliage.
As the weather warms, the plant produces flowering stalks, known as scapes, which offer a stronger onion flavor. Scapes can be cut and used in cooking, similar to spring onions. Removing scapes before the topsets fully develop can redirect energy back into the underground bulb or foliage production.
Timing the Bulbil Harvest
The bulbils develop at the apex of the scape, typically becoming ready for picking in mid-to-late summer (July or August). Readiness is indicated when the stalks start to arch or “walk,” and the bulbils feel firm and plump.
The papery outer layers covering the bulbils may begin to dry and show slight browning, signaling that energy transfer from the main plant is complete. Harvesting at this stage ensures maximum size for culinary use, where they offer a flavor profile often compared to shallots. Alternatively, mature bulbils can be left on the stalk to touch the ground, propagating the plant to a new location.
When harvesting, the entire stalk containing the mature cluster can be snapped off cleanly near the main stem. If the goal is propagation, the cluster can be gently twisted off the stem and immediately planted.
Harvesting the Main Underground Bulbs
The main underground bulbs are not harvested every year because the perennial plant benefits from being left undisturbed. Harvesting is reserved for thinning an overcrowded patch or when large, mature bulbs are desired, typically occurring every two to three years. The appropriate time to lift the underground bulbs is late fall or early winter, after the plant has entered dormancy.
The visual cue for harvest is the complete dieback of the entire plant structure, including the stalks and foliage, which will have fully yellowed and collapsed. This indicates the plant has stored maximum energy reserves in the underground bulb cluster. Digging prematurely can compromise the bulb’s size and storage potential.
To harvest, use a garden fork to gently loosen the soil away from the center clump to avoid puncturing the bulbs. Lift the entire cluster out of the soil, revealing the tightly packed group of attached bulbs. The bulbs can then be carefully separated and cleaned of excess soil.
Curing and Storing the Harvest
The post-harvest treatment for the various parts differs depending on the intended use. Green leaves and scapes are highly perishable and should be used immediately or stored briefly under refrigeration. The main underground bulbs, once separated and cleaned, require curing for long-term storage.
Curing involves placing the bulbs in a well-ventilated, cool, dry location away from direct sunlight for approximately two to three weeks. This allows the outer skin to dry and tighten, sealing the bulb and helping prevent fungal diseases. Once cured, the bulbs can be stored like common onions, typically in mesh bags in a cool, dark environment.
Bulbils can be stored in two ways: for culinary use, they can be kept refrigerated for several weeks. For replanting, they should be stored in a cool, dry place until the desired planting time, usually late summer or early fall.