Legal Question in Landlord & Tenant Law in California

Absolutely yes, if the lawn and trees are part of the leased premises and they are damaged due to lack of watering. The duty to maintain the rental property, normal wear and tear excepted, does not end at the doors if the leased property does not. I have had a couple of tenants who were shocked that I withheld from their deposits after they moved out and I discovered they had let plants die and the ivy in the back completely overgrow the planting beds. But I was entirely within my legal rights to charge them for a gardener to come in and cut everything back and replant the dead plants. After that I added specific language to my lease to avoid any misunderstanding, but it is not necessary to have that in the lease for it to be legally enforceable.

If, however, you are just talking about letting the place look shabby with brown grass, etc., but once things are watered they are fine, then no, you can't charge, because you have no damages.