Hoya plants, often called wax plants due to their thick, succulent leaves and star-shaped flowers, are popular houseplants known for their relatively easy care. These tropical climbers are epiphytes in their native Southeast Asian habitats. The most successful way to increase your collection of these desirable plants is through stem cuttings. This method allows growers to replicate the parent plant exactly and establish a new specimen quickly.
Selecting and Taking Hoya Cuttings
The best time to take a Hoya cutting is during the active growing season, typically spring or summer, when the plant is putting out new growth. To prevent the spread of disease, sterilize your cutting tool, such as sharp scissors or pruners, with rubbing alcohol before use. The cutting should be taken from a healthy, non-flowering stem and measure approximately three to five inches long.
The most important part of the cutting is the node, the small bump on the stem where a leaf or aerial root emerges, as this is where new roots will grow. Each cutting must contain at least one node, and ideally two, to maximize successful rooting. Make a clean, angled cut just below a node to provide maximum surface area for root development.
Treating the Cutting Before Planting
Once the cutting is separated from the mother plant, prepare it for its rooting environment. Start by carefully removing any leaves from the lower node or two that will be submerged in the rooting medium. This prevents the foliage from rotting, as decaying organic matter can introduce fungal or bacterial pathogens that inhibit root growth.
For many Hoya species, especially those with thicker, more succulent stems, it is beneficial to allow the cut end to “callous” or dry out. Lay the cutting in a dry, well-ventilated area for a few hours or up to 24 hours until a dry scab forms over the cut. This protective layer acts as a barrier against moisture-borne infections. While optional, applying a rooting hormone in powder or gel form to the cut end and nodes can stimulate faster root development.
Comparing Rooting Methods
Water Propagation
One popular method is water propagation, which involves placing the cutting’s node-bearing stem into a small glass of water. This allows the grower to clearly monitor root development, which typically begins within two to four weeks. The water should be changed weekly to replenish oxygen and prevent algae growth. Although water roots develop quickly, they are often more fragile and adapted to a purely aquatic environment. This adaptation sometimes leads to shock when the cutting is transplanted to soil.
Soilless Mediums
A highly effective alternative is rooting in a soilless, semi-hydroponic mixture like perlite or a blend of sphagnum moss and perlite. For the moss-based method, the sphagnum should be lightly moistened and squeezed to remove excess water. The moss is then wrapped around the cutting’s nodes and placed in a sealed container or bag to create a high-humidity “prop box.” This environment encourages robust root growth that is more accustomed to a solid medium.
Direct Soil Rooting
Rooting directly into a soil mixture is also possible, though it is generally slower and requires careful management to prevent rot. The ideal soil mix should be extremely light and chunky, such as a blend heavily amended with orchid bark, perlite, or pumice. This ensures excellent aeration and drainage. When planting, bury at least one node and keep the medium consistently moist but never waterlogged. The advantage of rooting directly into this substrate is that the plant is less likely to experience transplant shock later on.
Transitioning the New Plant
Once the new roots have reached a length of about one to two inches, the cutting is ready to transition to a permanent pot. Roots grown in water or pure sphagnum moss are susceptible to drying out and shock, so the transition must be gradual. If rooting occurred in water, gradually introduce small amounts of the final potting mix into the water over a week or two to help the delicate roots acclimate.
When potting up, select a small container with drainage holes and use a well-aerated potting mix, such as a blend designed for orchids or succulents. Gently transfer the rooted cutting into the mix, disturbing the new root system as little as possible. For the first two weeks, keep the soil damper than you normally would for a mature Hoya to bridge the moisture gap. New leaf growth is the definitive sign that the cutting has successfully established itself.