Lawn maintenance; how far do you go?

[Mark Forest]

I have several SFH. One home in particular has bald spots in the lawn. Some of the houses have weeds and brown areas. How far do most of you go to have nice lawns? I require tenants to mow the lawn, but I doubt they would go for paying for a spray company to fertilize. You can have houses with perfectly green lush lawns like on a golf course, but that would be very costly. What do you all do if anything?