Bearded, Siberian and Japanese irises grow 6 to 48 inches tall. The blossoms are nearly every color from white to nearly black, and they bloom in the spring. Irises like sunny, well-drained sites that are enriched by compost and peat moss. The foliage shape range from wide, flattened leaves to narrow grass-like leaves. After blooming, cut the flower stalks to prevent the formation of seeds. Do not cut the foliage back until it naturally dies back. The leaves provide food for the next season's blooms. Plant to accompany irises should disguise fading leaves and add color to the flowerbed.
Yarrow or achillea is a perennial that produces fern-like leaves with flat-topped flowers. The blooms are white, yellow and pink clusters of tiny flowers. These are produced at the terminal end of the plant stems. Yarrow usually grows 2 1/3 feet tall while the leaves form a low-growing mat. Yarrow is commonly used as cut flowers.
Asters grow 1/2 to 8 feet tall depending on the species. These plants produce leaves that are 1 to 5 inches long and have 1- to 2-inch daisy-like blossoms. Blooms are red, pink, purple and white. Asters give the flower garden late season color with an abundance of fall blossoms.
Coreopsis grows 6 to 18 inches tall in clumps that are 1 to 3 feet wide. They produce lobed foliage and yellow daisy-like flowers throughout the summer. Deadhead the dying flowers to achieve a prolonged blooming season. This flower is commonly used as a flowerbed border or groundcover.
Fountain grass or pennisetum grows 3 to 4 feet tall in clumps 2 to 3 feet wide. The grass blades grow 2 to 3 feet long. The foliage in the summer is bright green, but turns golden brown in the fall. Flower stalks reach 4 feet tall with 5 to 7 inch reddish brown plumes on top. These plumes are used as cut flowers during the summer.
Stokes aster, Stokesia or star flower is an upright perennial producing a solitary blossom at the end of a flower stalk. These flower stalks are short with dark to light blue flower discs. These blossom in late spring and continue throughout the summer.