The idea of mixed borders is becoming very popular, and with good reason. A flower bed of annuals is full of color all summer but dare I say, a solid mass of unchanging color can actually be a little boring? The trend in gardening these days is for variety. Mixed borders contain shrubs, perennials and annual flowers that all reach their peak interest at different times throughout the growing season, even into fall and winter in some cases.
Late summer is an excellent time to consider the advantages of a mixed border. The stars of my mid-summer garden have faded and are looking rather bedraggled, including bee balm, Shasta daisies, monkshood, Asiatic lilies, and daylilies.
Peonies and baptisia produce their gorgeous blooms in early summer but they both have beautiful foliage that lasts all summer. While they arent showy this time of year they do provide a nice backdrop to my later blooming perennials. Their foliage is also very nice as a filler in flower arrangements.
Amsonia is another early summer blooming perennial with nice foliage. This plant has long, narrow, willow-like leaves that add an interesting texture to the garden. An added bonus is the bright yellow color they turn in the fall. Amsonia has no pest or disease problems and is a good backbone plant for your mixed border.
The late summer to fall blooming perennials are coming into their glory now. My phlox is in full bloom and the rudbeckia (black eyed Susans) that I planted this spring as seedlings are at their peak, too. Sedum Autumn Joy is a wonderful perennial that no garden should be without. It spends most of the summer as an attractive, leafy plant but around the end of July its flower buds develop, looking like large heads of gray-green broccoli. These heads go through a gradual and very pleasing transition of colors from green, to shades of pink, to a deeper rosy pink when open, then deepening to a russet-purple that lasts well into winter.