Question
We just moved into an older home with an old olive tree in front of the house. It is very close to the main sewage line coming from the house. We called a roto-rooter guy and found out that we have roots in our main sewage line and it may be coming from the olive tree. There are also 2 palm trees (but they are on city property) that grow very near the msain line.  Any suggestions on what we should do to prevent big problem with our sewage drain? We are seriously thinking of cutting the olive tree.

Answer
Modern sewer pipe made of PVC cannot be invaded by tree roots.  Clay-type sectional piping, however, which is typically found on older home sites, can become completely filled with fibrous root extensions,

Recent research has shown that trees do not pierce sewer lines looking for water. In cases where there are roots in your sewer lines, this is generally the result of a sewer line which is damaged or leaking. Tree roots will then follow the source of the moisture into the pipes.


The problem with roots growing in sewer lines is that once inside, they grow until the pipe is plugged, causing drains to back up in the home.Plugged drains must be cleared by a plumber. Once unplugged, copper sulfate,available at most drugstores, can be used to prevent further plugging.Every six months, when the drains will not be used for 24-48 hours, flush one pound of copper sulfate crystals down a toilet bowl or wash them down a basement drain or clean out. The copper sulfate crystals kill roots in the pipes. Once the roots are killed,normal processes of decay occur.

I guess it is your choice--every few years have the drains cleared, use a chemical to help keep the lines clear, replace the old cracked lines with newer PVC pipe, or remove the olive tree. Palms do not have the reputation of clogging lines but if they are on top of the line the roots maybe a problem. The next time have the plumber try to tell how far into the pipe the clog is and then try to determine which tree maybe the problem. It maybe both the olive and the palms or only one.