Chrysanthemums, commonly known as mums, are a popular garden plant prized for their vibrant, late-season color. Multiplying these plants without buying new ones is achieved through propagation. Rooting cuttings in water is a simple and accessible technique that generates new, genetically identical plants from a healthy parent specimen. This method allows direct observation of the rooting process and requires only a few basic materials.
Essential Materials and Ideal Timing
The rooting process begins with gathering a few simple items. You will need a clean, sharp cutting tool, such as a knife or pruning shears, to prevent damage and disease. A clear glass vessel or jar is necessary to hold the water and cuttings, allowing you to monitor root growth. Finally, you should use clean water, with distilled water or rainwater often preferred over tap water.
The success of water propagation is influenced by the timing of the cutting. The ideal period is late spring or early summer, typically May or June, when the plant is experiencing vigorous growth. Cuttings taken during this phase are known as softwood cuttings, which are more pliable and root faster than older growth. Complete this process before the plant begins to set buds for its autumn bloom cycle.
Collecting and Preparing the Cuttings
Selecting a healthy, non-flowering stem from the parent plant is the first action. The stem should be new, green growth that is still flexible, rather than woody. The cutting itself needs to be between four and six inches long, which is a sufficient length for establishing a strong root system.
The cut should be made just below a leaf node, the slightly swollen point on the stem where a leaf attaches. This area contains a high concentration of auxins, the natural plant hormones responsible for initiating root development. Strip away all the leaves on the lower half to two-thirds of the stem, leaving only the top two or three sets remaining. This prevents submerged leaves from rotting and reduces moisture loss from the cutting’s surface.
For an added advantage, the cut end can be dipped into a rooting hormone before being placed in the water. Rooting hormones, available as a powder or gel, contain synthetic auxins that further stimulate the formation of new roots. While this step is not mandatory for mums, the application of hormone can increase the speed and density of root production.
Maintaining Cuttings While Rooting in Water
Once prepared, the cuttings must be placed carefully into the glass vessel so that the water covers the node area where the leaves were removed. The water should be deep enough to submerge the bottom nodes, but ensure that no remaining leaves are touching the water’s surface, as this will lead to decay. The developing cuttings thrive best in a location with bright, indirect light.
Maintaining a consistent, mild environment is beneficial, with room temperature conditions being ideal for root formation. Direct, intense sunlight should be avoided, as it can overheat the water and stress the cuttings. The regular changing of the water, which should be done every two to three days, is the most important maintenance step.
Replacing the water replenishes the dissolved oxygen supply necessary for the metabolic activities that lead to root growth. This action also prevents the buildup of bacteria, fungi, or algae, which can cause the stem to rot or the water to become stagnant. Small white roots should begin to emerge from the submerged nodes within two to four weeks. The cuttings are ready to be moved to soil once the new roots are approximately one inch long.
Moving Rooted Cuttings to Soil
The transition from water to soil is a sensitive time, as the water-grown roots are fragile and unaccustomed to extracting nutrients from a solid medium. Before planting, if the cutting will eventually reside outdoors, it benefits from a brief hardening-off period. Hardening off involves gradually introducing the cutting to outdoor conditions, such as short periods of shade and wind, over a few days.
A well-draining potting mix is the best medium for planting the cuttings. Amending the soil with materials like perlite or coarse sand helps prevent the soil from becoming compacted and waterlogged. Handle the new roots with care to avoid snapping them, and gently set the cutting into a small pot filled with the prepared mix.
The cutting should be planted at a depth that covers the newly formed roots and a small part of the stem above them. Immediately after planting, water the soil thoroughly to settle it around the roots and eliminate any air pockets. For the first few days, keep the newly potted plant in a location that receives partial shade to reduce transplant shock.