How can a Virginia association write a rule to enforce neat decks and patios?

I'm on the board of a townhouse association in southern VA.

While attempting to deal with a complaint from a member I realized that neither our covenants nor our rules & regs has a section or paragraph that specifically deals with owners maintaining a neat and orderly appearance on their decks and patios.

Several items skirt around the issue, but nothing direct and specific.

Anyone out there have a good sample? I'm just looking for something like "Owners shall be responsible for . . . " Thanks.