Lemon verbena (Aloysia citrodora) is a shrub prized for its intensely fragrant leaves, which release a distinct lemon-sherbet aroma. This herb is highly valued for its use in teas, cooking, and potpourri. Since the plant is sensitive to frost and difficult to grow from seed, propagation via cuttings is the most effective and reliable method for creating new, genetically identical plants. Cuttings allow gardeners to ensure the plant’s survival over winter and easily expand their collection.
Gathering Tools and Optimal Timing
Successfully propagating lemon verbena begins with gathering the correct tools. You will need a sharp, sterilized cutting instrument, such as small pruning shears or a razor blade, to ensure clean cuts and minimize the risk of introducing disease. Prepare a well-draining rooting medium, typically a sterile mix of peat moss and perlite or coarse sand, and a small pot or tray with drainage holes. Rooting hormone powder or gel can be included to boost the success rate of root formation.
The ideal time to take cuttings is late spring through early summer, when the mother plant is actively growing. During this period, the plant produces an abundance of softwood or semi-hardwood material that roots most readily. Warmer temperatures, ideally maintained between 64 and 77 degrees Fahrenheit (18 to 25 degrees Celsius), benefit the cuttings. This timing ensures the new plants have the full growing season to establish a robust root system before cooler weather arrives.
Selecting and Preparing the Cutting
Selecting the right stem from the mother plant is important for successful propagation. Look for healthy, non-flowering shoots that are soft toward the tip but firmer toward the base—this is known as semi-hardwood. The cutting should be approximately 4 to 6 inches long and taken from a stem about 1/4 inch in diameter. Use a clean, sharp tool to make a precise cut just below a leaf node, the point on the stem where a leaf attaches.
The leaf node contains a high concentration of auxins, or plant hormones, that promote root development. Remove all leaves from the lower half of the cutting to prevent rotting when inserted into the moist soil. Removing the lower foliage also reduces the total surface area, which helps conserve moisture since the cutting has no roots yet. If using rooting hormone, gently score the bottom inch of the stem with a razor to expose more cambium tissue, helping the stem absorb the compound.
Planting and Rooting the New Growth
After preparing the cutting, dip the cut end into the rooting hormone, ensuring the product fully covers the node and exposed tissue. Gently tap off any excess powder before planting to prevent a concentration that could inhibit growth. Use a pencil or small dowel to create a pilot hole in the moist rooting medium; this prevents rubbing off the rooting hormone. Insert the cutting into the hole, then gently firm the soil around the stem to ensure good contact and eliminate air pockets.
The new cutting requires a high-humidity environment to prevent desiccation while roots are forming. Place a clear plastic bag, a repurposed plastic bottle, or a humidity dome over the pot to create a mini-greenhouse effect. This cover traps moisture and maintains the necessary humidity, which should be checked daily to ensure the soil remains consistently moist but not waterlogged. Position the covered cutting in a location that receives bright, indirect light, as direct sunlight can overheat the mini-greenhouse and damage the growth. Roots typically form within three to six weeks; once new leaf growth or roots emerge from the drainage holes, the plant is ready to be transplanted.