Root of the problem: "The lease does not have a utility cap."

It sounds like the root cause is the tenant screening process, or lack there of, as you mention.  

Perennials, on the other hand, regrow from their roots each spring, which would make them "real estate" property, as they are part of permanent flora that is part of a piece of real property.

:Contact whatever licensing board is appropriate and sue them in small claims court.Had a similar situation at my daughter's rental property, where the PMC did the video scope that found cracked sewer line blah blah.We hired someone to snake the pipes - problem solved for about $100 as opposed to the $5,000 they were quoting including tearing up the street and city permits on and on.Yeah, we bought a triplex and the old landlord had the pipes snaked once a year for $200 to clear roots.

We snaked it, put tree root killer down the drain and I haven't heard anything about it since Feb.Whew!!!

Our prelim scoring is based on objective non-discriminatory items, such as if they are smokers, if they have lived in the area (have roots), have held job for over a year, income, how long they have stayed at previous addresses, how long they intend to stay, Facebook/google search, unverified look at criminal, bankruptcy, evictions, bank accounts.  

Dig down to the roots or any poison?

Once roots are in, it's history.

The lease states "Tenant shall pay for repair of any drain blockage or stoppages, unless caused by defective plumbing parts or tree roots invading sewer line."

In addition to the limb the roots have cracked our driveway and are lifting part of his drive so that the water flow comes to my drive and my house.My question is why am I responsible at all...having been notified there is a problem with his tree limb why should I have to do the leg work and pay half to enhance his property's safety and value?