Giant foxtail (Setaria faberi) is an annual summer weed that is also known as giant bristlegrass, Chinese foxtail, Japanese bristlegrass and Chinese millet. This plant is native to Asia and came to the United States sometime in the 1920’s, arriving in some type of grain.
Seeds emerge in the spring, germinate through late spring and early summer, and grow through late summer and early fall. The fibrous root system is shallow and needs warm weather to sprout. This invasive weed can grow as tall as 7 feet, but is usually about 2 feet tall. The vibrant green leaves can be up to 16″ long, and are between a half-inch and an inch wide. Leaves have small hairs on their top side. Come fall, flowering occurs, giving the plant bristly leaves that resemble a foxtail.
If it invades a crop – it especially loves corn and soybean fields – and is left unchecked during the growing season, the crops will see a reduction in their overall yield. Tomato and cabbage crops may be poisoned by this invading weed, which causes abnormal growth in both crops. Giant foxtail can also be seen growing wild along the side of the road, in landfills, along public right of ways and beside fences.
Giant foxtail is hard to mow down in fields. Herbicides are effective in controlling this weed, but only if it is growing in crops with broad leaves. The best way for farmers to eradicate this pesky weed is to plant alfalfa in the field every two years. Hand pulling and hoeing are the best ways to remove this weed from unwanted places. Lawns that are infested with giant foxtail need a weed control program implemented by a licensed lawn service.
The biggest problem with giant foxtail is in its ability to produce an abundance of seeds. Humans, animals, wind and water all help spread these seeds near and far. The good thing about this weed – if a good thing can be said about a weed – is that it is not toxic to humans or animals, and is not known to cause any type of allergic response.