Cement is a fine, soft, powdery-type substance. It is made from a mixture of elements that are found in natural materials such as limestone, clay, sand and/or shale. When cement is mixed with water, it can bind sand and gravel into a hard, solid mass called concrete.
Overview. While onions may be welcome in your vegetable garden, they are considered weeds in your lawn. Onion grass, a type of wild onion, often flourishes in yards, particularly in the southeastern region of the U.S. Like most common lawn weeds, onion grass can be eliminated with commercial herbicides and weed killers.tep 2. Cut onion grass very short to prevent flowering. Onion grass reproduces by flowering and seeding. By cutting onion grass to the same height as your lawn grass, you can stop it from spreading.
Other Ways to Kill Weeds. 1  1. Use salt as a weed killer. Try this method only if you want to eradicate weeds in an area where you do not plan to grow anything for several years -- perhaps around paving stones and in pavement cracks. 2  2. Kill the weeds with boiling water.