The Eustoma grandiflorum, commonly known as Lisianthus, is a highly valued cut flower prized for its delicate, rose-like appearance and remarkable vase life, often extending for two to three weeks. While commercial growers rely on seeds, this method is challenging for home gardeners due to the lengthy, 12-week period required to produce robust seedlings and the specific environmental controls needed for germination. Propagating Lisianthus from cuttings offers a more reliable and faster alternative for replicating desirable plants and achieving established growth quickly.
Choosing the Right Cutting
Selecting the correct plant material is the first step toward successful propagation. Cuttings should be taken from healthy, non-flowering stems to ensure the plant’s energy is directed toward root formation rather than bloom production. The ideal specimen is a semi-hardwood cutting, which is new growth that has begun to firm up but is not yet woody.
Aim for a cutting that is between 3 to 6 inches in length and possesses at least four to six sets of leaves. Using a sharp, sterilized blade, make a clean, angled cut just below a node, which is the point on the stem where root cells concentrate. Remove the lower two-thirds of the leaves, as these would otherwise be submerged in the rooting medium and likely rot, introducing pathogens.
Creating the Rooting Environment
The environment created for the cuttings must balance moisture retention with proper aeration to encourage root development while preventing fungal diseases. A sterile, well-draining rooting medium is necessary, such as a mixture of equal parts peat moss and perlite or a blend of coconut coir and vermiculite. This composition provides the necessary structure and drainage to avoid the overly saturated conditions that Lisianthus roots are sensitive to.
Before inserting the cutting, dip the angled, cut end into a powdered or liquid rooting hormone to stimulate root growth. Use a pencil or dowel to create a small hole in the rooting medium, then gently insert the cutting, ensuring the rooting hormone remains intact and the lowest node is covered. Compacting the medium lightly around the stem secures the cutting in place.
Providing bottom heat accelerates root development, as Lisianthus cuttings root best when the medium temperature is maintained between 70°F and 75°F. Place the planted cuttings on a heating mat and cover the tray with a clear plastic dome or bag to create a mini-greenhouse effect. This maintains the high humidity needed to prevent desiccation. Place the setup in an area that receives bright, indirect light, avoiding direct sun exposure which can overheat the enclosed environment.
Caring for New Lisianthus Plants
Root formation can take a month or two, and successful rooting is indicated by new top growth or a gentle resistance when the cutting is lightly tugged. Once a robust root system has formed, the newly established plants must be gradually acclimated to the lower humidity and harsher conditions of the garden or home. This process, called “hardening off,” prevents shock when the plant is transplanted.
Begin the hardening off period by removing the plastic humidity dome for increasingly longer periods each day over the course of a week to ten days. During this transition, keep the rooting medium consistently moist but never waterlogged, allowing the top layer to dry slightly before watering again. Lisianthus is susceptible to fungal issues, so ensuring excellent drainage remains paramount.
After hardening off, the new plant can be moved to a larger pot or transplanted into the garden. Avoid heavy fertilization immediately following the transplant, as the delicate new roots can be damaged by concentrated salts. Instead, begin with a weak, diluted liquid fertilizer solution, perhaps at a quarter of the recommended strength, applying it every two weeks to support initial growth.