Know all the rules about applications, online vs paper,  and have a thorough lease in place which states who is responsible for what-  gardening, pest control, repairs, snow removal, rules on trampolines above ground pools. 

You can do same with garden hose and nozzle set on mist spray It is not a dangerous or hard job if you do it correctly.Here all you have to do is haul to the landfill yourself which is about 40 miles,,,a nice drive. 

Are you sure that they are not "growing" indoors.  

Recently purchased a multi-family duplex down (foreclosed property) that has a basement unit that sets up perfectly for a one bedroom one bath rental unit.  There is common stairway access to the unit, and considering...

Using age as a guide to class is more accurate with garden-style Multifamily apartment complexes and that is the context of my previous answer as it is in Multifamily and commercial where you most commonly see the letter grade system.  

We do our own painting, fix drywall holes ourselves, repair our own closet doors, and replace kicked in door jambs. 

Indoor storage...

That's down from the high in the early Spring of 2019 of around $800 per night for some place like a Hilton Garden Inn.I've also seen the rent market soften since last Spring as well.  

The cats made horrible messes indoors and out on a regular basis.

Advertising things like a butterfly garden can help attract tenants.Negatives: Time commitment.