Foxtail is an annual weed that emerges during the summer. Its blades are wider, wispier and lighter green than most turf grasses. The weed produces shoots that have wide, brushy ends that look like green mascara wands. Foxtail stands out in lawns, because it grows faster than conventional grass. When the grass is mowed, foxtail grows and stands above the lawn within a day or two. Herbicides can be used to kill foxtail, but they are toxic and harmful to the environment, humans and pets. A simple household product kills foxtail quickly, without the need for toxic chemicals.
Purchase pure white vinegar. A concentration of at least 5% is needed, but higher concentrations yield faster results. Supermarkets stock concentrations of 5% and 9%.
Fill a clean spray bottle with the white vinegar. If you have sensitive skin, wash your hands if any of the vinegar drips onto them (particularly if you are using a higher concentration of vinegar).
Set the spray bottle to "stream," so that the vinegar comes out in one narrow stream of liquid. Vinegar also kills grass, so any grass that the vinegar touches will also die, so it is important to keep the nozzle set to "stream," so that you can control where the stream of vinegar falls. If you happen to get a few blades of grass wet with vinegar, don't panic. The existing turf spreads and grows together over the spots where grass is lacking.
Get as close to the foxtail as possible, and spray it with vinegar, completely saturating it. Move the spray bottle closer, and spray the base of the foxtail grass.
Reapply the vinegar weekly, if needed. Foxtail generally dies back within a day or two, but larger specimens--foxtail grows up to 3 feet tall-- may require additional treatment.
Pull out the foxtail from the lawn, when it has completely died back from the vinegar treatment.
Treat your lawn to make it thicker and fuller. Foxtail is an opportunistic grass weed that emerges when lawns are thin or patchy. Fuller lawns choke out foxtails before they emerge. Depending on the degree of patchiness in your yard, use fertilizer or grass seed on existing lawn to make it grow in fuller. If the grass is very patchy and sickly, remove existing sod and lay new sod.