The process of propagating a new plant from a simple stem section, known as taking cuttings, is one of the most accessible methods for gardeners to expand their collection of Sambucus species, or elderberry. Water rooting is a popular and straightforward way to propagate this plant due to its visual simplicity and minimal equipment requirements. This method allows growers to observe the entire root development process, providing an immediate indication of success. Elderberry plants respond readily to this technique, making it a reliable approach to creating genetically identical clones.
Selecting and Preparing the Cuttings
The most successful cuttings are taken from the plant’s new growth, referred to as softwood, during late spring or early summer. At this time, the stems are flexible but not yet woody. While hardwood cuttings can be taken in the dormant season, the new, green growth roots more quickly in water. Select a healthy stem that is about the diameter of a pencil and has not yet produced flowers to increase the likelihood of root formation.
To prepare the cutting, aim for a section between four and six inches long. Make the bottom cut at a slight angle just below a leaf node, which is where leaves and roots naturally develop. All leaves on the lower half to two-thirds of the cutting must be removed completely. Submerging foliage in water encourages decay and bacterial growth. Leaving at least one pair of leaves at the top allows the cutting to continue photosynthesizing and directs energy toward root production.
The Water Rooting Environment and Maintenance
Place the prepared cuttings in a clean container, such as a glass jar, filled with clean, non-chlorinated water (distilled or well water). The water level must be high enough to fully submerge the nodes on the lower half of the stem, but the top portion with the remaining leaves must stay above the water line. Place the container in a location that receives bright, indirect light. Direct sunlight can excessively warm the water and encourage algae growth.
Maintaining a stable environment is important for successful rooting, with a consistent room temperature between 65 and 75 degrees Fahrenheit being ideal for softwood. The most important maintenance step is replacing the water every three to five days to replenish oxygen and remove any accumulated bacteria or fungal spores. Root formation typically begins within three to six weeks, appearing as small, white bumps before developing into fine, white root structures. Healthy water roots are bright white and firm; brown or mushy areas indicate rot.
Transitioning Rooted Cuttings to Soil
The roots must be allowed to grow to an appropriate length before transplanting to ensure the cutting survives the transition to a soil medium. A root length of one to two inches is sufficient, especially when the roots have started to branch slightly. Roots grown in water are structurally different and often more fragile than those grown in soil, making this transition a vulnerable period.
The young plant must be “hardened off” to acclimate it to the drier conditions of soil and air. This involves gradually introducing it to outdoor light and temperature over about a week. Select a small starter pot, typically four inches in diameter, and fill it with a light, well-draining potting mix, such as one containing perlite or sand. Carefully plant the cutting, taking care not to damage the delicate water roots, and ensure the base of the stem is covered.
After planting, the new elderberry should be kept in a shaded or sheltered location to prevent immediate desiccation. The soil must be kept consistently moist for the first few weeks, but never soggy, to ease the transition for the newly formed roots. New leaf growth on the cutting is the sign that the plant has successfully established itself and can be moved to a permanent location.