Orchids are often propagated through vegetative reproduction, a method of asexual reproduction that yields a genetically identical clone of the parent plant. This technique ensures the new plant will possess the exact desirable traits of the original, such as flower color and size. For the home grower, using cuttings is one of the most accessible and reliable ways to multiply an orchid collection. Successfully growing an orchid from a cutting involves understanding the plant’s unique biology and following a precise sequence of preparation and environmental control.
Selecting the Right Orchid and Cutting Method
The success of propagation by cutting depends entirely on the orchid’s natural growth habit, which is divided into two categories. Monopodial orchids, such as Phalaenopsis and Vanda, grow vertically from a single stem. Sympodial orchids, including Dendrobium and Cattleya, grow horizontally, producing thickened stems called pseudobulbs or canes along a rhizome.
True stem cuttings, known as cane cuttings, are primarily taken from sympodial orchids like Dendrobium Nobile types. These cuttings utilize mature, flowered pseudobulbs that contain stored energy and dormant growth points (nodes) from which a new plantlet will emerge. Monopodial orchids are not typically propagated by cutting the main stem, but rather by removing specialized plantlets called keikis.
Keikis form naturally, or can be encouraged to develop, along the spent flower spike nodes of Phalaenopsis orchids. For the keiki to be viable as a cutting, it must mature on the mother plant until it has developed at least two to three leaves and an equal number of roots, each measuring two to three inches in length. This ensures the new plant has an established root system capable of sustaining itself once separated.
Preparing the Cutting and Supplies
Before making any cuts, all tools must be thoroughly sterilized to prevent the transmission of bacteria or viruses between plants. Use a sharp razor blade or clean shears wiped down with rubbing alcohol or a 10% bleach solution. Making a clean, precise cut minimizes the size of the wound and reduces the risk of infection.
Immediately after separating the cutting, both the wound on the mother plant and the cut end of the new piece should be treated with a protective agent. A powdered fungicide is effective, but common household cinnamon powder can also be used as a natural antifungal. This application seals the open tissue, preventing moisture loss and blocking the entry of pathogens.
The choice of potting medium is important for the rooting environment, which must be well-aerated yet moisture-retentive. Suitable materials include fine-grade orchid bark, coarse perlite, or long-fiber sphagnum moss. For cuttings, the medium should be moist but not saturated, mimicking the orchid’s natural epiphytic environment.
To encourage growth from dormant nodes, a hormone paste containing cytokinin is often used on Phalaenopsis flower spikes. This promotes the formation of a keiki rather than a new flower spike. Cane cuttings benefit from a rooting hormone powder combined with a fungicide applied to the cut ends before planting.
Planting the Cutting
The planting process depends on whether you are handling a cane cutting or a keiki. For sympodial cane cuttings, the mature pseudobulb should be cut into segments, with each segment ideally containing three to four nodes. These pieces are then laid horizontally across the surface of the prepared rooting medium, such as moist sphagnum moss.
The cane should be pressed lightly into the surface, ensuring at least one node is in firm contact with the damp medium without being buried. The stored energy and latent buds within the nodes are activated by warmth and humidity to produce new roots and a plantlet. The medium should be placed in a shallow tray or pot.
Keikis, which already possess roots and leaves, are potted vertically into small, clear containers. The small size helps the tiny root system establish itself without being overwhelmed by excess moisture. The keiki is positioned so its roots are gently nestled into the fine-grade orchid mix, and the pot is then backfilled.
Stabilization is often necessary for the top-heavy keiki to prevent movement that could damage the fragile new roots. A small stake or wire clip can be used to secure the plantlet to the side of the pot. Labeling the container with the orchid’s name and the date of propagation is necessary for future reference.
Care for the Newly Potted Cutting
The initial care for a newly potted cutting focuses on creating a stable, high-humidity microclimate to encourage root development. The ideal environment requires a consistent, warm temperature, maintained between 70 and 80°F. This warmth stimulates metabolic activity, which is necessary for the dormant nodes to begin active growth.
To maintain high humidity levels (70% or more), a simple mini-greenhouse can be created by placing the pot inside a clear plastic bag or under a clear dome. While this traps moisture, lift the cover daily for a brief period to allow for air exchange. This prevents the buildup of stagnant air, which promotes fungal growth. Placing the pot on a humidity tray filled with pebbles and water is an alternative method to increase local moisture.
Light exposure must be bright but strictly indirect to avoid scorching the tender new leaves and canes. Direct sunlight can quickly overheat the cuttings, especially within a sealed humidity dome. The medium should be kept lightly moist, but never soggy, to prevent the cutting from rotting. Misting the surface of the medium daily is often preferred over a full soaking until the cutting has developed a robust root system.
The rooting process requires patience, as it can take several weeks or even months for the cutting to establish itself. Successful rooting is confirmed by the appearance of bright green or white root tips extending into the medium, or by the cutting becoming firmly attached to the potting mix. Once significant new root growth is observed, the cutting can gradually be acclimated to lower humidity levels.