Crape myrtles are perfectly safe to plant near your home – and your driveway, patio, walkways and front sidewalk – because they don't have aggressive or invasive root systems. But before you plant a crape myrtle near your home, patio or other spot where its summer-long blooms will be fully appreciated, make sure the location meets the plant's needs for full sun and good air circulation.
The spectacular large flowers of heat-loving, summer-blooming crape myrtle trees, shrubs and dwarf groundcover varieties would, by themselves, convince most people to plant them. But they also display good fall color with appealing, exfoliating bark and attractive, graceful branching – if you don't butcher it with your pruning shears and destroy its natural form, a practice referred to in gardening circles as "crape murder." Trees tolerate a variety of soils and can become quite drought tolerant, but they grow faster and bloom better with some irrigation and fertilizer. Crape myrtles come in white, pale lavender, darker lavender, pale pink, rose pink, cherry red and true red.
Because even the tallest crape myrtles rarely reach 30 feet and their root systems can tolerate some restriction, crape myrtles are well-adapted to locations with limited space -- in planters, near sidewalks or driveways, in sidewalk or traffic medians and under utility lines. They can also be used in spacious settings as specimen trees. Under-planting them with hungry and thirsty annual or perennial flowers is not wise, because the crape myrtle's many surface roots will be forced to compete for water and nutrients. But a less aggressive groundcover will be fine. Plant tree-type crape myrtles at least 10 feet from your home or other walls when using them for foundation plantings.
Unlike trees that send down taproots and extensive lateral roots, crape myrtles have a shallow fibrous root system – one reason they're sensitive to soggy ground and require well-drained soil. Trees should always be planted at the same level at which they originally grew in the nursery, or slightly higher, to make sure they don't get "wet feet." Prepare planting holes that are much wider than they are deep, to allow for lateral root expansion. When you backfill, mix in plenty of well-composted organic matter, to improve drainage and also encourage and feed new roots. Mulch the entire root areas, to protect roots and conserve soil moisture.
Crape myrtles don't flower well anywhere but in full sun, so avoid even partially shaded locations. Sunny exposures also help prevent powdery mildew, the moisture-borne scourge of all but the most disease-resistant crape myrtles. Good air circulation – leaving plenty of distance between plants and buildings, solid walls and other plants – also helps prevent or deter powdery mildew. Improve the soil with organic matter to bolster texture and drainage. Crape myrtle can be planted in spring, summer and even early autumn in some climates. Plant before fall if possible, so roots get established before winter dormancy.