Since varieties of wild allium grow in most U.S. regions, according to a pamphlet produced by the National Sustainable Agriculture Information Service, you can see this often white flower-topped grass growing in your own back yard. As long as you haven't treated your yard with pesticides, or you don't have lead in your soil, the wild onion or garlic is safe to eat. As you would with any foraged food, always wash it thoroughly first.
Smell the air. Often large groups of wild allium smell faintly of garlic or onion.
Look for tall, grasslike clumps of plants. Wild allium stalks are round and stronger than most other weeds.
Examine the plant's leaves. Wild allium has long, flat leaves. Very broad leaves may indicate Allium tricoccum, or ramps, which are also known as wild leeks.
Examine the plant's flowers. Allium flowers droop from the top of leafless stalks, are yellow or purple, but usually white, bell-shaped and have multiple points. A group of these small, drooping, star-shaped blooms appear from each flowering stalk. Their midveins are green.
Remove the plant at its root. Grasp the plant close to the ground, and lightly tug back and forth until you work the plant out of the ground, root and all. If you see a tiny onion at the end of the plant, it's wild leeks, onionweed, also known as Allium triquetrum or wild garlic, known as Allium ursinum.
Bring your plants home and wash them thoroughly in water. Break a stalk in half. The taste should tell you what kind of wild allium you've picked: wild leeks, onionweed or wild garlic are the most likely varieties.
According to the Sacred Earth website, sometimes wild garlic leaves host fox tapeworm eggs, which can be fatal if ingested by humans unless they are detected early. Significantly reduce your risks of ingesting these eggs by thoroughly washing your food before eating it. Any food that grows near the ground where foxes live may host this species of tapeworm egg. Cooking or drying the leaves also eliminates much of your risk.