Tenant's Children's friends causing problems.

[Steven Yu]

Hi Bigger Pockets,

My wife and I own a 3 unit property and we currently live in one of the units. Each unit is 3 bed 2 baths. Our tenants are okay, they pay on time every month for the last 2 years since we've bought the place. They are pretty amicable and don't bug us about every little thing and only emergencies. One of the tenants is a single mother with 3 children between 8 - 14ish and their grandma. The kids are decently well behave but the problem is, sometimes they have friends over and sometimes they hang out by the porch where my wife has potted plants and flowers and sometimes they would bounce the ball and it would destroy the plants. I've told them whenever I see them and told their mom and grandma about it multiple times (10 + times) in the last 2 years for them to talk to the kids' friends. Today they just busted another flower so my wife wants to raise the rent. We are fairly inexperienced landlords, so if anyone has any advice for this situation, that would be great. Short of running a security system with camera, how do we prevent this in the future. The other tenant has one child that's around 7 or 8 but the kid never plays on the porch or outside so I'm pretty sure it's always that one particular tenant.