The goldfish plant (Nematanthus) is a popular houseplant recognized for its striking, tubular flowers that resemble small, leaping goldfish. These vibrant blooms typically emerge from trailing stems, making the plant an attractive choice for hanging baskets and shelves. Propagating this plant is a simple and effective method for generating new specimens from a healthy parent plant. Utilizing stem cuttings allows gardeners to create genetically identical copies of the original plant.
Preparing for Propagation
The best time to propagate goldfish plants is during the active growing season of spring or summer, when increased light and warmth promote robust growth and root development. Select healthy, pliable, green stems that are semi-ripe and approximately four to six inches long. Ensure the chosen stems do not have any flower buds, as the plant’s energy should be diverted toward forming new roots rather than blooms.
Gathering the necessary tools beforehand simplifies the process and ensures a sterile environment. Use sharp shears or a knife, sterilized with rubbing alcohol to prevent disease transmission. Prepare a rooting medium that is moisture-retentive yet well-draining, such as a mix of perlite, vermiculite, and peat moss or coir. A powdered or gel rooting hormone can also be used to encourage quicker root development and increase the overall success rate.
Step-by-Step Stem Cutting Technique
Once the materials are ready, use the sterilized cutting tool to make a precise cut on the selected stem. The cut should be made at a slight angle just below a leaf node—the slightly swollen point where a leaf attaches. This location contains the cells necessary to differentiate into new roots. Cuttings should measure between three and six inches in length to provide enough energy for establishing a new root system.
Next, carefully remove the leaves from the lower one or two nodes of the cutting, ensuring the nodes themselves are not damaged. Removing this lower foliage prevents the leaves from being submerged in the rooting medium, which could lead to rotting and fungal issues. If using a rooting hormone, gently dip the cut end of the stem into the powder or gel, shaking off any excess.
To plant the cutting, use a pencil or a small dowel to create a planting hole in the prepared rooting medium. This prevents the rooting hormone from being wiped off and avoids damage to the stem tissues when inserting it. Place the cutting into the hole, ensuring at least one leaf node is buried beneath the surface where the roots will emerge. Gently firm the medium around the base of the cutting to ensure good soil-to-stem contact and stability. Water the medium lightly but thoroughly until it is evenly moist, but not saturated.
Ensuring Rooting Success
After planting, the immediate environment must be carefully managed to ensure successful root establishment. Goldfish plant cuttings thrive in warm temperatures, ideally maintained between 65°F and 75°F. High humidity (around 50% or more) is beneficial because it minimizes water loss through the leaves while the cutting is unable to take up moisture without roots.
To achieve high humidity, you can cover the pot with a clear plastic bag, creating a miniature greenhouse effect. Alternatively, place the pot within a humidity dome or on a pebble tray filled with water to elevate moisture levels. Position the planted cutting in a location that receives bright, indirect light, such as near an east or west-facing window. Direct sunlight must be avoided, as the intense light and heat can quickly scorch the cutting or dry out the rooting medium.
Keep the rooting medium consistently moist but refrain from overwatering, which can lead to stem rot. Roots typically begin to form within a few weeks, and the first sign of success is the emergence of new leaves at the top of the cutting. Once the cutting demonstrates active new growth and resists a gentle tug, indicating a developed root system, it is ready to be transitioned into a standard potting mix and treated as a mature plant.