Here in Phoenix, we have a problem with nut grass. It has a deep root with a nut from which other roots grow. I have found it very difficult to kill this grass with herbicides. What can I use?
The most effective way to get rid of nut grass is to pull it up by hand and make sure you get the nut. Another solution is to cover the area with black plastic and leave it on for the entire growing season. The heat generated by the Sun and held in by the plastic will be enough to destroy the nut.