I just rigged a spider's web of wire over one of the planters. LOTS of room for an enterprising squirrel to squeeze through, of course, but it might act as deterrent - I don't know. We'll see. I got WOKEN UP THIS MORNING by the little buggers digging around in there, and I'm not having it, however funny my husband thinks I am being. If this doesn't work, it's chicken wire. And then flame throwers when I see a squirrel anywhere near there.