Garlic Gone Wild

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Wild garlic (Allium vineale) and wild onion (Allium canadense) are very common lawn weeds. These plants are winter perennials with an odor of garlic, wild garlic being the prime problem maker in NC. Wild garlic (Allium vineale) is often confused with wild onion and for good reason. Both look like grasses and even wild garlic can have an onion smell when crushed. The best way to tell the difference is to look at the leaves. Wild onion has flat, solid leaves while garlic has hollow, round leaves. These plants emerge in late fall from underground bulbs and grow through the winter and spring. In late spring a basal bulb covered by a membranous coat forms. The greenish pink to purplish flowers are borne in clusters at the stem tip. The plants die back in early summer. The underground bulbs can persist in the soil for several years.

Fortunately, there are solutions for controlling them. With a small number of weeds, pulling, though difficult, is an option. It’s likely, however, that bulblets will be left in the ground and new leaves will later re-emerge to make even more plants. For best results, dig them out with a thin trowel if they haven’t already taken over your lawn.

Unfortunately, there are no preemergence herbicides that will control wild onion or wild garlic. They must be treated with a postemergence herbicide, and you have to be diligent. Plants will need to be treated more than once and for more than one season. That thin, glossy leaf makes it hard for herbicides to stick to. After applying treatment, do not mow for at least two weeks.

Treat wild garlic and wild onion in November and again in late winter or early spring before these plants can produce the next generation of bulbs in March. However, be careful not to apply most weed killers onto Centipedegrass or St. Augustinegrass during their spring green up period. Inspect the lawn again in the spring and the next fall, and treat if necessary.

Recommended herbicides include Imazaquin, the active ingredient in nutsedge herbicides, and will provide control for wild garlic and wild onion. This product should not be used on fescue and should not be applied to warm season turf during green up in spring. Wait at least 1-½ months after treatment before reseeding, winter overseeding or plugging lawns. This product is not for use on newly planted lawns, nor on winter over-seeded lawns with annual ryegrass.

Three-way broadleaf herbicides containing 2,4-D, dicamba and mecoprop (MCPP) will provide control of wild garlic and wild onion with repeat applications. Look for these active ingredients in granular products at your local garden center, they are on the shelves right now. These products can be used safely on most turfgrasses, but you must read and follow the label because some grass types can not tolerate these chemicals. Apply during November, very early spring, and again the next November for best control. Do not apply these herbicides during the spring green up of warm season turfgrasses, or over the root zone of nearby ornamental trees and shrubs. Do not apply these products to newly seeded grasses until well established (after the third mowing). Treated areas may be reseeded three to four weeks after application.

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