How do you handle water bill and landscape maintenance?

Greetings;

I am curious how other LLs handle watering costs for maintaining landscaping.  I have offered my tenants a set amount each month they can deduct from the rent for costs of water to keep landscaping (trees, shrubs, small lawn etc) healthy, not just alive.  

If I expect them to cut the lawn, do I have to provide them with a lawn mover? I rent a SFH in CA.

What/how do you tackle this?

thanks

Kelly