the link you provided is great but mainly deals with month-to-month leases.
Which is why I prefer statutes rather than guides.
Ours is a year's lease and we fully intend to allow the tenants to stay the full period of the lease. We just want to know what proper course of action to take to ensure that we advise them that the lease will not be extended, and if such a notice is indeed necessary.
Section 1945 of the CA landlord tenant statute does address month to month tenancies but there is a sentence in that section that says:
"It shall be competent for the parties to provide by an agreement at the time the tenancy is created that a notice of the intention to terminate the same may be given at any time not less than seven days before the expiration of the term thereof."
You have complied with the statute by including the 30 day notice clause in the lease so you are good to go.
The statute goes on to say:
"The notice herein required shall be given in the manner prescribed in Section 1162 of the Code of Civil Procedure or by sending a copy by certified or registered mail addressed to the other party."
Section 1162 addresses methods of delivery of the notice and can be read in its entirety at:
CA Codes (ccp:1159-1179a)
The upshot is that it would be best to put it in writing and hand it to the tenant. Bring a witness in case testimony is later necessary. I would not use certified mail as many people duck certified mail as bad news and you won't know for three weeks that they didn't accept it. Generally, however, just the sending of the certified mail is sufficient whether the tenant claims it or not, but you really don't want to get into that kind of hassle because a dispute over receipt of notice means you get to go to court with a holdover tenant.
Back to Section 1946, the statute also requires you to include the following wording in your notice:
"State law permits former tenants to reclaim abandoned personal property left at the former address of the tenant, subject to certain conditions. You may or may not be able to reclaim property without incurring additional costs, depending on the cost of storing the property and the length of time before it is reclaimed. In general, these costs will be lower the sooner you contact your former landlord after being notified that property belonging to you was left behind after you moved out."
Section 1946 can be read at:
CA Codes (civ:1940-1954.1)
We have not been happy with the way they are maintaining the property
About that, it's probably too late for this tenancy but, in the future, if there is non-compliance with the terms of the lease you immediately jump on it by giving proper written notice of the non-compliance and give the tenant the appropriate amount of time to cure the non-compliance. The the non-compliance is not cured within that time you file for eviction.
All that is explained in the statute and if you continue to be a landlord you need to know the statutes backward and forward. A mistake on your part could be quite costly.
Fortunately, that guide helps to understand the basics and has footnotes to the statute sections. If you ever have to go to court you'll need to cite statutes, not the guide.