Many of the daisy-like flowers such as Rudbeckia, Helenium, Symphyotrichum, and Chrysanthemum will form a mass of flowers that will eventually topple over the edge of the beds. While a cascade of color can be attractive spilling over the edge, it looks very unsightly when you expose the brown bare centers of the plants. It is best to stake these plants as a group or clump.
Tall perennials with large flowers like Lilium, Delphinium, Crocosmia, and Dahlia will benefit from individual stakes.