More than 5 Feet Tall

• Plant these tall perennials at the back of the border. One of the tallest perennials, hollyhock, grows from 5 to 8 feet tall. This perennial thrives in full sun and blooms in midsummer with white to purple blossoms. Hollyhocks are hardy in U.S. Department of Agriculture Plant Hardiness Zones 5 to 9 and prefer well-drained soil. The larkspur grows to 6 feet tall and produces towers of white, pink and blue flowers in early to midsummer. Hardy in zones 2 to 7, larkspurs prefer full sun and well-drained soil. Other perennials that grow more than 5 feet tall include Joe Pye weed, foxgloves, plume poppies and dusty meadow rue.
  
  

From 3 to 5 Feet Tall

• Plant 3 to 5 foot tall perennials near the back of the bed. Golden Marguerites grow to 3 feet tall and bloom in late summer with yellow blossoms. Hardy in USDA zones 3 to 7, these perennials thrive in full sun and tolerate dry soils. For long-lasting blue color, plant alkanet in light to partially shady spots. This drought-tolerant flower grows to 5 feet tall and is hardy in zones 3 to 8. Other moderately tall perennials include false indigo, blackberry lily, butterfly bush, monkshood, bellflower, false sunflower and globe thistle.
  
  

From 1 to 3 Feet Tall

• For the middle of the border, choose perennials growing between 1 and 3 feet tall. These include the Shasta daisy, a 3-foot tall perennial with white flowers blooming from June through August. Shasta daisies grow best in USDA zones 5 to 9 in sites with full sun. Canterbury bells bloom from late spring to midsummer with large, blue-and-white, bell-shaped blossoms. Plant these 3-foot-tall perennials in zones 3 to 8 in sun and well-drained soil. Other perennials in this height range include bellflowers, peach bells, astilbe, gas plant, red valerian, sweet William and bleeding heart.
  
  

Less than 1 Foot Tall

• Creeping phlox fills in the front of the bed.Jupiterimages/Photos.com/Getty Images
  
  Plant the smallest perennials at the front of the bed. Low-growing choices include basket of gold. This yellow-blooming flower grows to a foot high and produces an abundance of spring blossoms. Basket of gold thrives in USDA zones 3 to 7 in full sun and well-drained to rocky soil. The cheddar pink only grows to 6 inches tall and produces pink flowers above dense, deep-green foliage. Cheddar pinks bloom in late spring and prefer full sun and well-drained soil. Other small perennials include lily of the valley, false rockcress, red barrenwort, spotted dead nettle and creeping phlox.