Crape myrtle (Lagerstroemia) is a popular deciduous shrub or small tree recognized for its showy, long-lasting summer blooms. Propagating through cuttings is a method of vegetative reproduction that creates a genetic duplicate of the parent plant. This ensures the new specimen retains the exact flower color and growth habit. This technique allows gardeners to expand their collection or preserve a favored cultivar without genetic variability.
Preparation and Timing
Successful propagation begins with selecting the correct time of year. Crape myrtles respond well to two types of cuttings: softwood and hardwood. Softwood cuttings are taken from the new, pliable growth of the current season, typically collected between May and July. This cutting type roots quickly, usually within four to eight weeks.
Hardwood cuttings are taken from dormant, mature stems in late fall or winter. They root successfully but require a longer period for root development, sometimes taking several months. Gathering all necessary materials beforehand streamlines the process. You will need sharp hand pruners or a clean knife, a container with drainage holes, a rooting medium, and a rooting hormone product.
The ideal rooting medium provides support, good aeration, and moisture retention. A mixture of equal parts peat moss and perlite is a common choice, though 100% perlite also offers excellent drainage and airflow. Sterilizing the cutting tool with rubbing alcohol prevents the transfer of plant diseases.
Taking and Treating the Cutting
Proper selection of the plant material influences the rooting success rate. Look for a healthy, non-flowering shoot from the current season’s growth that is about the thickness of a pencil. The cutting should be between four and eight inches in length, containing at least three or four leaf nodes.
Make a clean, angled cut just below a leaf node, which is where roots are most likely to form. This angle increases the surface area for water absorption and hormone uptake. Next, gently strip all the leaves from the lower two-thirds of the cutting, leaving only two to four leaves at the very tip.
If the remaining leaves at the top are very large, trimming them in half will reduce water loss through transpiration, limiting stress until roots can form. The cut end is prepared with a rooting hormone, which contains synthetic auxins like IBA (Indole-3-butyric acid) to stimulate root initiation. Dip the base of the cutting into the powdered or liquid hormone, coating the bottom inch or two, then gently tap off any excess material.
Establishing the Cutting in the Medium
Before inserting the treated cuttings, the rooting medium must be properly prepared. Fill the container with your chosen mix and moisten it thoroughly until water drains from the bottom holes. The medium should be damp but not saturated, as excess water can promote fungal diseases and rot.
Use a clean dowel or pencil to create a narrow planting hole for each cutting. Creating a hole first prevents the rooting hormone from being scraped off the stem as it is inserted. Plant the cutting deep enough so that at least one of the exposed leaf nodes is submerged beneath the surface, typically about three to four inches deep.
Gently press the medium around the stem to ensure good contact between the cutting and the soil particles. The cutting requires a high-humidity environment, created by covering the container with a clear plastic bag or a propagation dome. Use a wooden skewer or wire hoops to hold the plastic away from the foliage, preventing moisture buildup directly on the leaves.
Post-Planting Care and Transplant Readiness
Once established, the container should be placed in a location that receives bright, indirect light. Direct, intense sunlight can cause the interior of the plastic covering to overheat and scorch the delicate cutting. The ideal temperature range for root development is warm, around 70 to 80 degrees Fahrenheit.
Monitor the humidity inside the dome daily; if condensation is heavy, lift the plastic briefly to allow ventilation and prevent the growth of mold or rot. The soil moisture should be maintained consistently, keeping it evenly moist without ever allowing it to dry out completely. Mist the medium occasionally if the humidity appears to be dropping.
Rooting typically occurs within four to eight weeks, depending on the cutting type and environmental conditions. Signs of successful rooting include the appearance of new leaves that remain firm and do not wilt. A more definitive test involves lightly tugging on the cutting; resistance indicates that new roots have anchored the stem.
Before moving the rooted plant, it must be acclimated to normal environmental conditions through a process called “hardening off.” Gradually remove the humidity cover over about a week, exposing the plant to ambient air and lower humidity levels. The rooted cutting can then be transplanted into a larger pot or directly into the garden, waiting until the following autumn or spring for planting outdoors to ensure the root system is robust.