They claim they have had to trim the tree, resort to extensive clean-up and the excessive growth has caused vermin and other creatures to feed off the tree.I researched California tree law and learned that the neighbor has a right to trim the parts of the tree that are extending onto their property but don't have a legal claim/dispute against me unless harm is caused.

These policies ultimately cause more harm to the people politicians are trying to help.As investors it is easy for us to focus on the hard economic facts that these policies are terrible for our customers and communities. 

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

I'm always wondering when you're unable to evict tenants what would be the harm in taking them to small claims court?

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

We don’t know anyone in the area, but you might want to read our series about “How to Screen a PMC Better than a Tenant”, since selecting the wrong PMC is usually more harmful than selecting a bad tenant: https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesAdditionally, don't treat property management like a commodity and just focus on the lowest price!

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

You're getting money off the table and out of harms way completely.Secondly, although depreciation is a cool concept. 

Tenants will ask for unreasonable things that can harm your business.