Hi, There are many perennials that do well in the same conditions as phlox. Black-eyed Susan and Coneflower are two that come to mind. But, if your phlox is tippy it will still be best to offer it support with plant stakes because without support, the phlox will just flop on your other flowers. Gardener's Supply sells a wide selection of plant stakes, including the grow-thru type which work really well if you install them over the tops of your phlox before they get too tall. Now is a good time to add them. They are located at www.gardeners.com As far as plant selection goes, you can go to our Plant Encyclpedia on this site and do an Advanced Search, plugging in your criteria and it will give you a plant list.