You really do not need a new lease to get the point across that you want to be paid in full and on time. Nothing says pay on time like a Pay or Quit notice. Call next time your tenant is late and tell him you are going to start leaving a reminder on his door when the rent is due. Then post your P/Q notice. Also tell your tenant you have been thinking about hiring a lawn service for his place but you will need an increase in rent to cover it. Every tenant has a shelf life. Your tenant sounds like he is past the expiration date. There is nothing wrong with your current lease. If your tenant needs to be reminded of his obligation to pay in full and on time he can read it from the P/Q notice you will nail to his door.
Thank you! You've given me an option I had not considered. I think I will start with just a 60 day notice of rent increase, hopefully he will just accept it, but I doubt he will. I've learned a lot from reading the questions and answers on this forum.