I have a rental and I am wondering if I can depreciate mulch, gardening soil, annual flowers and perennials? 

This usually involves fresh mulch, flowers, etc. 

In some jurisdictions you can drain the gray-water into a flower bed.

We xeriscape  the front yards on our sfr's(rocks, gravel, flowering low water desert plants, bushes, drip systems)  and  leave the back yards to the tenants to care for.  

We’ve seen it in every thing including flowers, real estate, stock, bonds, mutual funds, dot coms, etc.

You don't need to break the bank buying tons of plants and trees and whatnot; just have him mow it nicely, edge the sidewalks, trim the bushes, and cut out a few flower beds.

All you need is one good candidate.Try to add some color to your exterior photos, even if it is silk flowers in a tub.   

I understand that the shade is being cast by the seller.These are the thoughts and questions that my mind raises: Every time a weed gets watered, it grows stronger allowing it to choke the flowers around it.Are you rewarding and enabling his behavior by going through with the deal? 

.- we planted a good amount of flower in the spring.

Wouldn't you say so @Mike Flowers ?