Egyptian Walking Onion

Lift established clumps in spring and pull them apart into a few generous divisions, replanting at roughly 4 to 5 inches apart in full sun. Unlike multiplier onions, they do not need lifting and replanting every year - divide only when the clump has gotten thick. The plant multiplies from the base as well as from its topsets, so a clump left alone keeps packing new shoots into the same footprint; spring division resets the spacing as growth is starting.

From the second season onward, cut the tender young shoots as you would chives and use them as scallions. Leave a new planting alone through its first season so it can establish. A first-year clump is still building the underground bulb that drives every later flush of greens, and cutting into it early costs you the stand.

Give about one inch of water per week when rainfall does not cover it. Sandy ground needs it more often and in smaller doses than clay. An inch a week is what keeps the greens tender and mild rather than tough; sandy ground drains it away faster than clay holds it, so the same rain goes further in heavier soil.

During hot dry weather, spread the leaves apart and look at the youngest inner leaves and down in the neck for silvery streaking, browning leaf tips, and slender pale insects. Count thrips per leaf, not per plant. On walking onions the injury is mostly cosmetic, so clear old plant debris from the bed and around it rather than reaching for an insecticide. Onion thrips run five to eight generations a year and outbreak in hot dry summers, preferring the youngest leaves and sheltering down in the neck where they go unnoticed until the leaves silver and the tips brown - but on this crop that damage is primarily cosmetic, so sanitation is the proportionate answer.

When the cluster of bulbils at the stalk tip fattens and the green skins color up to reddish-brown, and the stalk begins to bend, cut the whole cluster. Eat the bulbils, store them for a few months, or replant them where you actually want the next clump. Once the cluster outweighs the stalk it topples and the bulbils root where they land, walking the planting two to three feet a year - taking the topsets is what keeps the bed where you put it.

Start walking onions from topset bulbils, never from seed. Press them 1 to 2 inches into loose soil with the pointed end up, about 6 inches apart, in full sun. They will take any time the ground is not frozen, but fall is the best window. Each topset is already a small onion carrying its own root initials, so an autumn planting roots before freeze-up and moves at the first thaw - the same head start the plant gives itself when a loaded stalk topples over and the bulbils root where they land.

After planting bulbils in fall, lay a light cover of straw over the row. Keep the cover thin - the bulbils are set only one to two inches deep and are not meant to be buried. The bulbils sit barely an inch or two under the surface, so a light straw cover buffers that shallow root zone through the freeze-thaw of winter without smothering it.