An urban forester explains the root of the problem.

Q:My 30-foot ornamental plum tree has sent its roots into the 1890s clay tile sewer line. It needs to be snaked about twice a year. The tree is at the front of the house; about 15 feet back from the ...

Question: Recently the sewer line in my house backed up. The plumber who cleaned out the line discovered that tree roots were the problem. I've seen products that you flush down the toilet for this.