Wild onions and crabgrass - Knowledgebase Question

Spartanburg, So
Question by tjist
December 27, 2009
I have centipede grass and every year in the fall thru the winter I can'yt get rid of the wild onions and crabgrass, can you help me?

Answer from NGA
December 27, 2009


Wild garlic (Allium vineale) and wild onion (Allium canadense) are winter perennials. They emerge in late fall from underground bulbs and grow through the winter and spring. In late spring, aerial bulblets are formed and the plants die back in early summer. The underground bulbs can persist in the soil for several years. While both have thin, green, waxy leaves, those of wild garlic are round and hollow, while those of wild onion are flat and solid. There are a few control options. Pulling: With a small number of weeds, pulling, though difficult, is an option. It?s likely, however, that bulbs or bulblets will be left in the ground and new leaves will later re-emerge. For best results, dig them out with a thin trowel. Mowing: Mowing will not kill wild garlic or wild onions. Regular mowing can weaken plants and prevent them from setting seed. Chemical: Unfortunately, there are no preemergence herbicides that will control wild onion or wild garlic. They must be treated with a postemergence herbicide, and persistence is the key. Plants will need to be sprayed more than once and for more than one season. One characteristic that makes control difficult is that both have a thin, glossy leaf to which herbicides don?t readily adhere. Adding a spreader-sticker to the spray solution will help it to adhere evenly. Be aware that some products have a spreader-sticker already added. Unlike most weeds, mowing wild garlic or wild onion immediately before applying an herbicide may improve uptake. After application, do not mow for at least two weeks. Timing of Sprays: Treat wild garlic and wild onion in November and again in March. However, be careful not to apply most weed killers onto centipedegrass or St. Augustinegrass during their spring greenup period. Treat it now, or early next spring. Next year, inspect the lawn in the fall and treat if necessary. Recommended Herbicides: Imazaquin, the active ingredient in Image, will provide control for wild garlic and wild onion. This product should not be applied to warm season turf while it is beginning to green in early spring. With persistence, you can eradicate wild onion.

Crabgrass is easier to prevent than to eradicate. You can use Vigoro Ultra Turf Crabgrass Preventer. It keeps crabgrass seeds and other grassy weeds from germinating. Crabgrass Preventer with Dimension? keeps on killing crabgrass up to 4 weeks after it sprouts. Dimension? also prevents the sprouting of many broadleaf weeds, such as spurge, chickweed, and henbit. Be sure to follow label directions. Best wishes with your eradication project!

You must be signed in before you can post questions or answers. Click here to join!

« Return to the Garden Knowledgebase Homepage

Member Login:



[ Join now ]

Today's site banner is by TBGDN and is called "Irises 2017"