Nutgrass, also known as nutsedge, has grassy foliage but is not a true grass. The plant grows from small, nutlike tubers in the soil. If you're persistent, pulling out all new shoots that you see every couple of weeks, you may be able to get rid of a small patch of nutsedge in your lawn by hand-pulling. There are also a couple of herbicide options. One is a chemical called bentazon (Basagran). It's available from garden centers that carry lawn chemicals. Also, you can get products with the chemical MSMA in them. Look for products with "nutgrass killer" in their name. One last note: Often (not always), nutgrass becomes a problem because of poor drainage. Check to see whether the nutgrass is growing in a wet area. If it is, you may be able to discourage it by improving the drainage and drying out the site.