Renter wants to plant flowers/garden asking to deduct rent for it

[Amanda Dehaas]

Renter wants to plant flowers/garden asking to deduct rent for it. Or just plant a garden and build an area to garden in general. But - here's the thing - the back part of our apt complex is divided so each person has a little area to themselves. The front area is open, there is no grass but I would consider a "common area". I was going to plant some trees this summer to make it look nicer....so how should I respond to this tenant? Say hell ya make it nicer, but no I can't deduct rent? What have you guys done in the past? 

Also - had another tenant plant a tree without asking....weird or not weird? Thoughts? Any rules anyone has implemented?