Bentgrass, also known as creeping bentgrass, is a cool seasonal grass that grows rapidly in wet conditions, especially where turf is closely mowed. It is described as puffy, dense patches of fine-textured grass. In the spring it spreads quickly and crowds out other grasses. In the summer it typically browns and looks dead. When bentgrass is dormant in the summer, annual weeds will take its place and start taking over your lawn.
Once growing on your lawn, this bad grass can be very tricky to remove. Your best bet is to remove the patches of bentgrass and try re-sodding your lawn all together. Bentgrass is difficult in the fact that it can affect other parts of your lawn that you may not see. Typically, its seeds remain in the area surrounding the original patch.