Wild onion, also known as wild garlic (Allium vineale) is a winter perennial. The leaves are waxy, upright and needle shaped growing 8- to 12-inches long. The leaves of wild garlic are hollow and round and have a strong odor. The leaves of wild onion are solid and flat and appear directly from the bulb. Both plants grow from underground bulbs. The membrane-coated bulbs of wild garlic are flattened on one side and have bulblets. Wild onion bulbs are white inside with a strong odor and are covered with a fibrous, scaly coat. The white to light green flowers of wild garlic develop on short stems above aerial bulbs. Wild onion does not have a stem; white to pink flowers with six elliptical segments. Both wild onion and wild garlic spread by bulbs, seed and bulblets. Both plants flower from April through June. Both wild onion and wild garlic are distributed throughout the United States.
Keep wild garlic cut short, even if the turf does not yet require mowing. This will weaken the underground bulbs and prevent flowering. Wild garlic is a vigorous plant and can become a problem in thin turf or in dormant warm-season turf. Turfgrass should be kept dense through good disease and insect control. Winter protection of warm-season turfgrasses can be important.
The early spring, cool weather growth of wild onion and wild garlic will likely require the use of an ester post-emergence herbicide for control. For optimum control, make your herbicide application to wild onion and wild garlic plants that are actively growing and 2- to 12-inches tall.