Tree roots in your drain system will not only clog your drain but can damage your pipes. The first step in prevention of tree roots in you drain system is a careful selection of what trees are planted in your lawn in the firsts place. There are some fast growing varieties of trees like willow, poplar and birch that will quickly seek underground water and get into the drain system. You can consult a local horticulturalist for more details. Regular inspection will stop the roots before they get too large to handle. The best way to inspect is have a plumber do a regular video camera inspection. You can purchase chemical root treatments, but some people feel that the chemical will leach into the water systems and choose to use a rotating auger, placed into the pipe. The sharp blades will cut off the roots.