Dethatching your lawn can sometimes be a rough process for your lawn to handle but sometimes it is a necessary one. Here are some ideas from Dawn West from All About Lawns to let you know how and when you should think about dethatching. Thatch is not always a bad thing, but it will be soonAny amount less than 1/2 Inch is not a bad amount of thatch. It has the ability hold in moisture during times of drought and high heat.