Natal Plum (Carissa macrocarpa) is a favored plant known for its attractive appearance and resilience. This evergreen shrub is often chosen for landscaping due to its glossy foliage, fragrant white flowers, and edible red fruits. Propagating Natal Plum allows gardeners to create new plants, expand their landscape, or share this appealing species with others.
Choosing a Propagation Method
Gardeners typically choose between propagating Natal Plum from stem cuttings or from seeds. Cuttings generally produce new plants that are genetically identical to the parent, ensuring desired traits are preserved and often leading to faster establishment and maturity, with new plants potentially bearing fruit sooner.
Propagating from seeds, conversely, can introduce genetic variation, meaning the resulting plants may not be exactly like the parent. While this genetic diversity can be interesting, seed propagation generally takes longer for plants to reach maturity and begin flowering or fruiting. The choice depends on whether genetic exactness and speed of growth or potential genetic variation is preferred.
Propagating from Cuttings
Selecting and Preparing Cuttings
Begin by choosing healthy, semi-hardwood stems from the current season’s growth, about 4 to 6 inches long and free from disease or pests. Using a sharp, sterile pruning tool, make a clean cut just below a leaf node. Remove the lower leaves from the cutting, exposing a few nodes, and leave only one to two sets of leaves at the top. Applying a rooting hormone to the cut end can stimulate root growth and improve propagation success.
Rooting Medium
An ideal rooting medium provides good drainage and aeration for preventing rot and encouraging root development. A mixture of moist sand is suitable, or a blend of one part sand, one part peat moss, and two parts loam. Ensure the chosen container has adequate drainage holes.
Planting and Environment
Insert the prepared cuttings into the rooting medium, ensuring the nodes where roots will form are buried. After planting, create a humid environment around the cuttings to prevent moisture loss from the leaves and stems. This can be achieved by placing a humidity dome or a clear plastic bag over the cuttings, ensuring the plastic does not touch the foliage. Position the planted cuttings in a location that receives bright, indirect light, as direct sunlight can be too intense for newly planted cuttings.
Care During Rooting
Maintain consistent moisture in the rooting medium, keeping it moist but never waterlogged. Overwatering can lead to fungal issues and rot. Regularly inspect the cuttings for signs of root development, which typically occurs within 4 to 8 weeks. Gentle tugging on a cutting can indicate root formation if a slight resistance is felt. Maintaining a steady soil temperature, potentially with bottom heat, can also encourage root formation and speed up the process.
Propagating from Seeds
Seed Collection and Preparation
Collect seeds from fully ripe Natal Plum fruits, which are dark red or purple. Thoroughly clean the seeds to remove any fruit pulp, as this can inhibit germination. Natal Plum seeds benefit from soaking in water for 24 hours before sowing to help initiate germination.
Sowing Seeds
Prepare a well-draining, sterile potting mix for sowing the seeds. This helps prevent damping-off disease, which can affect young seedlings. Sow the seeds shallowly, about 0.25 to 0.5 inches deep, and provide adequate spacing between them to allow for initial growth. A warm environment is beneficial for germination, with optimal temperatures for Natal Plum growth ranging between 68 to 100 degrees Fahrenheit (20 to 38 degrees Celsius).
Germination and Seedling Care
Maintain consistent moisture in the seed-starting mix, ensuring it remains moist but not saturated. Germination can occur within two weeks, but initial seedling growth may be slow. Provide bright, indirect light to the young seedlings. As they grow, monitor them for any signs of pests or diseases. If multiple seedlings emerge too closely together, thinning them out can help ensure each seedling has enough space and resources to develop properly.
Caring for New Natal Plum Plants
Once Natal Plum plants have successfully rooted or germinated, proper care is important for their continued development. This includes transplanting, acclimatization, and ongoing maintenance.
Transplanting
When the young plants have developed a robust root system, they are ready to be transplanted from their rooting medium or seed tray into individual pots. This transition is best done during mid-spring to early summer or late fall to late winter to avoid extreme temperatures. Select pots that are 2 to 3 inches wider than the current root ball, ensuring they have good drainage holes. Use a well-draining potting mix, possibly a blend of garden soil with sand or perlite, to support healthy root establishment.
Acclimatization
Newly transplanted plants need a period of acclimatization to gradually adjust to less humid or outdoor conditions. Begin by placing young plants in a shaded area, progressively increasing their exposure to sunlight and outdoor temperatures over one to two weeks. This gradual process helps prevent shock and prepares them for their new environment.
Initial Care
Provide consistent watering to the new Natal Plum plants, ensuring the soil remains moist but not waterlogged; allow the top inch of soil to dry out between waterings. Young plants benefit from a balanced, slow-release fertilizer or one with higher nitrogen and phosphorus to support leaf and root development. Apply fertilizer every 6 to 8 weeks during the growing season, following product instructions carefully to avoid over-fertilization. Protect young plants from extreme weather, such as frost or intense heat, and monitor for pests during this establishment phase.