Tips

• Most trees produce an abundance of surface roots 12 to 36 inches deep that collect water and oxygen for the tree. To avoid potential root damage from planting year after year with annual flowers, create a perennial flower bed. Perennials result in a flower bed under the trees that is only disturbed when it becomes overcrowded. Use small seedlings in 2 1/2- to 4 1/2-inch containers so the planting hole is well above the root line. Plant taller flowers closer to the tree trunk and place shorter plants away from the trunk.
  
  

Inner Zone

• Plant taller flowers closer to the tree but still fitting below the lower branches. Columbine (Aquilegia x hybrida) reaches 12 to 24 inches tall bearing white, yellow, red and pink downward-facing blossoms in the summer. Hardy begonia (Begonia grandis) produces clusters of delicate pink summer blossoms on stems that reach 18 to 24 inches in height. Italian arum (Arum italicum) grows tall flower spikes to 12 to 20 inches in height covered with white flowers in the late spring. Bright red berries appear after the flowers have faded, and the leaves emerge in the fall and last throughout the winter.
  
  

Middle Zone

• The middle zone is the area under the tree that is for the flowers that are the size between the tall and short flowers. Cranesbill geraniums (Geranium sanguineum) reach 8 to 12 inches tall producing five-petaled magenta blossoms. Hyacinth bletilla (Bletilla striata) is a terrestrial orchid producing purple blossoms on 8- to 10-inch stems. Lady's mantle (Alchemilla mollis) covers the tops of its 8- to 10-inch-tall leaves with tiny yellow flowers. Plumbago (Ceratostigma plumbaginoides) grows 8 to 12 inches in height with five-petaled blue flowers appearing in the summer through the fall.
  
  

Outer Zone

• The outer zone is the area that blends the flower bed into the lawn with the placement of shorter flowers. Auricula primroses (Primula auricula) produce tubular yellow blossoms in spring on 2- to 8-inch flower stems. European ginger (Asarum europaeum) reaches 4 to 6 inches tall with purplish-brown, three-petaled tiny flowers among evergreen leaves. Labrador violets (Viola labradorica) creep in the shade at 1 to 4 inches tall with purple flowers appearing in the spring. Sweet woodruff (Galium odoratum) is a 4- to 8-inch-tall ground cover with small white spring flowers.