tenant complaints about messy neighbor

[George P.]

well, this is a new one for me. normally it's the other way, but my tenant and the neighbor share a driveway (the driveways are attached to each other).

and the neighbor is messy. i noticed that while updating the house. their garbage cans fall over, no one picks them up. boxes are blown all over, noone picks them up. cig butts, tampon boxes, you name it, it's all over the driveway.

the tenant has an "option to buy" the house and they like the home a lot. but they are complaining about the trashy neighbor.

i know the neighbor. she is weird (does not smile and weird sense of humor), but i know her. have her number in my phone too, so i can talk to her.

i just dont know what to say that might change her behavior...

suggestions?