Dog area in community back yard?

So I have a community back yard. Which means I don’t have a gate or fence to keep my dogs in. I was cleaning this up (in the process that’s why there’s boxes everywhere) and thought I could block off that little area for them to get outside time. I usually bring them to my parents so that they can run around and play (they have 2 1/2 acres) and be on grass. I usually tie my dog with a long rope and let her run around on the community grass. My So’s dog stays close so she doesn’t need to be tethered. Would it be mean to have them be on rocks though? I was thinking about moving the rocks so it’s just dirt and then when we move put them back. But it’d be nice for them to off leash at home even though it’s little. Should I do it or no???? It would even be nice to let them be outside for a couple hours just while we are running errands or even just so they aren’t laying around in the house. I can’t put up temp fences over the grass because people will complain and there are HOA rules. Plus that would be a Lot of fence. Bad idea or good?