Lagerstroemia (Crape Myrtle)

Crape myrtles are shrubs and small trees indigenous to temperate and tropical regions from Asia to Australia. The “myrtle” in their name is a nod to the similarity of their leaf shape of a true myrtle (Myrtus). The “crape” part—sometime written as ”crepe”—refers to their brightly-colored flowers, crinkly enough to look like they are made of crepe paper.

Thrives in Sonoma County

Several attributes make crape myrtles a wonderful addition to Sonoma County gardens.

• Besides adapting easily to our hot summers and mild winters, they offer weeks of bloom in mid-to-late summer and into autumn, usually July to October or earlier.
• Blossoms may be palest pink or lilac to deep pinkish red, red, purple, and white. They are among the longest-blooming of all trees.
• Once flowers have faded, dramatic fall color and interesting bark become focal points.
• Foliage is medium-to-deep green in summer, sometimes bronze-tinged, before turning shades of yellow, peach, orange or red in autumn.
• Bare branches in winter reveal mottled exfoliating bark, multi-colored in shades of tan and gray on certain cultivars. 

Selecting a Tree or Shrub

There are two important considerations when selecting a crape myrtle: structure and blossom color.

• Plants are available either as single- or multi-trunked specimens.
  • Multi-stemmed trees are more shrub-like as they develop height and require more space near ground level as they mature.
  • Single-trunked trees develop a round crown that may be difficult to prune, although pruning is optional, and wide-spread branches on a narrow trunk appear out-of-balance to some gardeners.
  • Multi-stemmed plants may be cut just above ground level in early spring to maintain a low profile.
• Selecting a plant in flower assures you of purchasing the exact blossom color you want.
  • Flower colors vary considerably from one plant to the next, even among those that have the same cultivar name.
  • Purchasing a plant out-of-bloom risks having a mislabeled plant tag and an unexpected flower color.

Low-Maintenance Plants

When planting a crape myrtle, keep in mind that flowering is most prolific in full sun.

• Choose a site where there is enough room to develop a full crown. In maturity, many selections become quite large, spreading 15-25 ft. high and as wide.
• A 5- or 15-gallon shrub will become a small tree within 10 years, though never developing an enormous trunk the way many shade trees do.
• Regular water is needed after planting and during the first 1-2 years; once established, only low water is needed.
• Good drainage is important to prevent soil from becoming water-logged, which will stymie growth and damage roots.
• Pruning is not essential but it does maximize flowering and enhance shape. 
• Pruning stimulates new branch growth—all blooms occur on the tips of new wood. Prune no later than February or March, allowing time for new growth.
• Branches may be cut back 12 to 18 in. for controlling shape; excessive pruning can cause overproduction of branches and unattractive density.
• Little pruning is needed after careful pruning the first few years.
• Remove all suckering shoots from around the base of the plant, internal dead or crossing branches, and any extremely long branches.
• Little debris is noticed after small leaves drop; they are easy to clean up for compost or to leave on top of mulch.
• Crape myrtles are generally trouble-free when sited properly, although they are susceptible to powdery mildew; however, by selecting a resistant variety, this problem rarely surfaces. There are a series of resistant hybrids developed by the U.S. National Arboretum known as the Indian Tribe Group with names such as ‘Cherokee’ (deep pink/almost red flowers) and ‘Seminole’ (medium pink flowers). 

August 2023