Growing new orchids from existing plant material, known as vegetative propagation, allows hobbyists to multiply favorite specimens at home. Although orchids lack the typical stems found on many common houseplants, specialized sections of the plant can be harvested and encouraged to develop into independent clones. This technique bypasses the lengthy and complex process of growing from seed.
Understanding Orchid Stem Propagation Types
The term “stem cutting” in orchid growing generally refers to three distinct types of plant material used for propagation. The most straightforward method involves removing a keiki, a naturally occurring small plantlet that forms directly on the flower spike or cane of the parent plant. Keikis are miniature clones that have often developed their own root structures before removal. A second common practice is using flower spike cuttings, where sections of a recently bloomed spike are cut and treated to force the formation of a new plantlet from a dormant node.
The third method involves cane or pseudobulb divisions, often used for genera like Dendrobium or Cymbidium. This process utilizes older, leafless back bulbs or sections of a cane that still possess viable growth nodes. While all three methods achieve vegetative reproduction, keikis and flower spike segments are most commonly associated with the idea of a “stem” cutting among home growers. Propagating from a flower spike requires inducing a plantlet to grow, whereas a keiki is typically ready for separation once its roots are established.
Preparing the Cutting and Necessary Supplies
Preparing the cutting and sterilizing tools minimizes the risk of infection. Instruments, such as a razor blade or sharp shears, must be sterilized using a 70% isopropyl alcohol solution or by heating the blade with a flame. Making a clean, swift cut reduces trauma to the parent plant and the cutting itself. For a flower spike, cuts are typically made in sections containing one or two nodes, leaving a small amount of spike material on either side. When separating a keiki, ensure the plantlet retains all of its existing roots.
Once the cut is made, the exposed tissue of both the new segment and the parent plant must be treated immediately. Applying a fungicidal powder or a cinnamon paste to the parent plant’s cut surface helps seal the wound against pathogens. If propagating from a flower spike, a specialized rooting paste containing plant hormones (keiki paste) should be applied directly to the dormant node to stimulate new growth.
Establishing the Plantlet in Growing Media
The prepared cutting needs a temporary growing environment to encourage root development. Small, clear plastic containers or seedling trays are preferred, as they allow monitoring of root progress and media moisture levels. Sphagnum moss is the most common rooting medium for keikis and spike cuttings due to its capacity to hold moisture and provide a stable anchor. The moss should be lightly moistened, not saturated, before use. A keiki should be placed gently on the moss so its roots are nestled into the medium, but the base remains slightly above the surface.
Spike cuttings can be laid horizontally or slightly angled on top of the medium. Immediately after planting, the cutting requires a highly humid environment to prevent desiccation and stimulate root growth. This is achieved by placing the container inside a clear plastic bag, a plastic dome, or a small terrarium setup. The first watering should be a gentle misting or light soak that allows for complete drainage, ensuring the roots do not sit in standing water.
Ongoing Care for New Orchid Growth
Once established, the new orchid cutting requires a specific environment to transition into a mature specimen. Newly established cuttings thrive under bright, indirect light, slightly lower in intensity than that provided to a mature orchid. A location near an east-facing window or a shaded spot near a south-facing window is often ideal. Consistently high air humidity, ideally between 70% and 80%, is necessary during the initial months of development.
Watering frequency depends on the humidity setup, but the sphagnum moss must be allowed to approach dryness before being watered again. Overwatering commonly causes failure, leading to root rot. The emergence of new, healthy root tips indicates successful establishment. Once the plantlet develops several roots that are at least one to two inches long, it can be gradually transitioned out of the high-humidity environment. At this point, a very dilute, balanced orchid fertilizer can be introduced at one-eighth to one-quarter of the recommended strength to support vegetative growth.