The crepe myrtle (Lagerstroemia indica) is popular for its vibrant summer blooms, but it often produces basal shoots (suckers) and root sprouts that become a nuisance. These growths are clones of the parent plant, emerging from the root system or the trunk’s base as a natural mechanism for survival. While some suckering is normal, a profuse outbreak usually signals that the tree is under stress or has been subjected to improper care. Addressing these unwanted shoots requires a dual strategy: immediate removal combined with long-term cultural adjustments to discourage their return.
Understanding Why Crepe Myrtles Produce Shoots
Crepe myrtles produce shoots as a survival instinct, triggered by external factors. Shoots emerge from dormant buds on the root crown or lateral roots, a process called adventitious growth. This mechanism allows the tree to rapidly replace lost canopy mass or compensate for energy deficits. The most common trigger for aggressive suckering is improper pruning, often referred to as “crape murder,” where main branches are severely cut back.
This drastic removal sends a hormonal signal to the tree’s base, forcing it to utilize stored root energy to produce a flush of weak, rapid shoots. Physical damage to the roots, such as from lawnmowers or trimmers, also stimulates root sprouts. Environmental stress, like drought or nutrient imbalances, may also increase basal shoot production as a sign of distress. While some suckers are inherent to the species, excessive growth almost always points back to a management issue.
Immediate Physical Removal Techniques
Physical removal is the fastest and least chemically intensive method for immediate control. The effectiveness depends on thorough removal, as simply cutting the top growth encourages the root to produce multiple new sprouts. The goal is to remove the shoot as close to its point of origin on the root or trunk as possible, minimizing the stub left behind.
When removing basal suckers from the trunk, use sharp bypass pruners or loppers to make a clean cut flush with the main trunk. For root sprouts in the soil, carefully scrape away mulch to expose the root attachment point, then cleanly sever the shoot right at the root surface. Small, tender shoots can often be twisted and pulled off by hand, which removes the entire growth point. Physical removal is temporary and must be consistent, because the root system attempts to replace lost growth using stored energy reserves every time a shoot is cut.
Chemical Strategies for Root Suppression
If physical removal is insufficient or impractical, chemical strategies can offer sustained suppression, though they require careful application. The primary options are systemic herbicides and specialized plant growth regulators (PGRs). Systemic herbicides, such as those containing glyphosate or triclopyr, are absorbed by the cut or foliage and translocated down to the root system to deplete its energy reserves.
The most targeted application method is the cut-and-paint technique, which minimizes risk to surrounding plants. This involves cutting the shoot close to the ground and immediately painting the concentrated herbicide directly onto the fresh wound. This immediate application is important because the plant quickly initiates a natural wound-sealing process that can block the herbicide’s entry. Triclopyr-based products are often favored for root sprouts in lawns because they are broadleaf-specific and less likely to damage surrounding turfgrass compared to non-selective glyphosate.
PGRs, such as those containing naphthalene acetic acid (NAA), are commercial “sucker stopper” products applied to the freshly pruned area. These PGRs chemically inhibit the growth of new shoots for a single growing season, offering a preventative measure. Always read and follow the product label precisely, as misapplication can damage the main tree’s roots or surrounding vegetation. Repeated treatments over time are typically necessary to fully exhaust the root system’s stored energy.
Long-Term Maintenance to Prevent Recurrence
Stopping crepe myrtle shoots depends on addressing stress and modifying maintenance routines. The most significant preventative measure is adopting proper pruning practices and completely avoiding the severe cutting known as “crape murder.” This aggressive technique stresses the tree and creates an imbalance that forces the plant to compensate by producing basal shoots.
Instead of topping, focus on selective pruning in late winter or early spring to remove only dead, damaged, or crossing branches, which maintains the tree’s natural form and health. Another crucial adjustment involves protecting the root zone from mechanical injury. Avoid using string trimmers or lawnmowers near the trunk, as minor bark abrasions can stimulate suckering.
Proper mulching is also beneficial: apply a thin layer, keep it several inches away from the trunk flare, and never pile it into a “volcano” shape. This practice reduces stress and the incidence of basal growth. By reducing stress and eliminating physical damage, the tree’s energy is directed toward canopy growth and flowering rather than unwanted shoots.