Chrysanthemums, commonly known as mums, are a favorite for gardeners due to their vibrant, late-season color that extends the bloom period well into autumn. These flowering plants are typically propagated through division or cuttings, with the latter being a highly efficient and cost-effective method for multiplying specific varieties. Taking cuttings is an asexual propagation technique that produces clones genetically identical to the parent plant, guaranteeing the new mums will possess the exact desirable traits of the original.
Selecting and Taking the Cuttings
The ideal period for taking chrysanthemum cuttings is during the late spring or early summer, before the plant begins to set flower buds. Targeting this vegetative growth stage ensures the plant’s energy is focused on root development rather than floral production. Cuttings should be taken in the morning when the stems are fully turgid, which improves their resilience during the rooting process.
Look for non-woody, new growth shoots that are actively growing but not yet hardened. The best length for a cutting is typically between three and five inches long, taken from the soft tip of a healthy stem. Using a sharp, sterilized blade or pruners is important to make a clean cut just below a leaf node. This area contains a higher concentration of naturally occurring growth hormones, giving the cutting a better chance of forming roots quickly.
Preparing and Rooting the Cuttings
Prepare the stem sections by minimizing water loss and directing energy toward root initiation. Remove all leaves from the lower two-thirds of the cutting, as any foliage submerged beneath the rooting medium will likely rot. If the remaining upper leaves are large, cutting them in half horizontally can further reduce transpiration.
The cut end of the stem should be dipped into a commercial rooting hormone. This hormone stimulates cell division and root formation at the wound site. Gently tap off any excess powder before planting to prevent over-application, which can sometimes burn the delicate plant tissue.
The cuttings should be inserted into a sterile, well-draining rooting medium such as a mixture of peat moss and perlite, coarse sand, or a specialized cutting mix. Keep the medium consistently moist but never waterlogged. A pencil or dibber can be used to create a hole in the medium before inserting the cutting, which prevents the rooting hormone from being scraped off the stem.
Maintaining high humidity around the foliage is a requirement for rooting success, as it minimizes stress while the cutting lacks roots to absorb water. This is often achieved by covering the pot with a clear plastic dome or bag, creating a mini-greenhouse effect. Place the container in a location that receives bright, indirect light, and maintain a consistent temperature, ideally around 70°F (21°C), which supports rapid cell growth. Under these conditions, the cuttings should begin to form roots within two to four weeks.
Acclimating and Transplanting
After the initial rooting period, move the new plants to a less protected environment. A gentle tug on the stem will reveal resistance if roots have formed. If the cuttings were placed along the edge of a clear pot, new, fine white roots may become visible against the container wall.
The transition from the high-humidity, controlled environment to the harsher outdoor conditions must be gradual, a process known as “hardening off.” Start by placing the cuttings in a sheltered, shady outdoor location for just one to two hours a day, then bring them back inside.
Progressively increase the duration of time the plants spend outdoors, and slowly expose them to increased light intensity and air movement. Once the plants are fully acclimated, they are ready for their final planting location. Transplant the new mums into a larger pot or directly into the garden bed.
Ongoing Care for Established Mums
The soil should be kept uniformly moist, but excellent drainage is necessary, as waterlogged conditions can lead to root rot. Mums are vigorous growers and require adequate hydration, particularly during dry spells or if they are planted in containers.
A technique called “pinching” is important for cultivating a dense, bushy plant with abundant flowers, as the natural growth habit tends to be tall and sparse. Begin pinching when the new plants are about six inches tall by using your thumb and forefinger to remove the top half-inch of the stem. This action breaks apical dominance, causing the plant to redirect energy into developing lateral shoots below the pinch.
Repeat the pinching process every two to three weeks. This encourages continuous branching and a compact form, which is structurally stronger and produces a higher volume of blooms. Stop all pinching by early to mid-July, which allows enough time for the plant to naturally set its final flower buds for the autumn display. A balanced, all-purpose liquid fertilizer can be applied every four to six weeks during the active spring and summer growth phase to ensure the plant has the necessary nutrients for healthy development.