Canna lilies provide a vibrant display in garden settings with their large leaves and striking flowers. Propagating these plants offers a practical way to increase their numbers, cultivate more plants or share them. This process also allows gardeners to enjoy these plants without the recurring expense of purchasing new ones. Multiplying canna lilies extends their presence in a garden.
Understanding Canna Propagation
Canna lilies are propagated through two methods: dividing rhizomes or sowing seeds. Rhizome division often yields faster results, producing mature plants faster, and ensures the new plants are genetically identical to the parent. Propagating from seed, however, can introduce genetic variability, potentially leading to new flower colors or plant characteristics. The best time for propagating cannas, especially through division, is in late winter or early spring, before new growth emerges.
Propagating Through Rhizome Division
Rhizome division begins with carefully lifting the dormant plant from the soil. After lifting, gently remove soil from around the rhizomes to expose their structure. Rinsing the rhizomes with water aids in cleaning them and making the “eyes” or growth buds more visible.
Examine the rhizome cluster for healthy, firm sections that possess at least one distinct “eye” or growth bud. These eyes appear as small, pointed protuberances from which new shoots will emerge. Using a sharp, clean knife or pruners, carefully cut the rhizome into smaller sections, ensuring each piece has at least one eye and a portion of the fleshy rhizome attached. Clean cuts prevent disease entry and promote quicker healing.
After division, allow the cut surfaces of the rhizome pieces to air dry for a day or two. This drying period, known as curing, helps cuts callus over, forming a protective layer that reduces rot once planted. Once cured, plant each division horizontally in a pot filled with a well-draining potting mix, covering it with approximately 2 to 4 inches of soil. Place the pots in a warm location, ideally around 60-70°F (15-21°C), to encourage root development and new shoot growth.
Propagating From Seed
Propagating canna lilies from seed requires preparation due to their hard seed coats. The outer layer of the seed must first be scarified, a process of gently scratching or nicking the coat to allow water absorption. This can be achieved by rubbing the seeds with sandpaper or carefully nicking them with a small file or nail clippers, avoiding damage to the inner embryo. After scarification, soak the seeds in warm water for 24 to 48 hours, which softens the seed coat and initiates germination.
Once prepared, plant the seeds about ½ inch deep in a moist, well-draining seed starting mix. A mixture of peat moss and perlite or vermiculite provides an appropriate growing medium. Maintain a consistent soil temperature of 70-75°F (21-24°C) for optimal germination, which occurs within one to three weeks. Providing bright, indirect light will support the emerging seedlings, ensuring they receive adequate energy for initial growth.
Post-Propagation Care
After propagating canna lilies, initial care is important for establishment. Immediately after planting, water newly potted rhizome divisions or seeded trays thoroughly to settle the soil. Maintain consistent moisture in the soil, ensuring it remains damp but not waterlogged, which can lead to rot. Placing newly propagated plants in a warm environment encourages root development and shoot emergence.
Ensure young plants receive ample, indirect light to support healthy growth without scorching delicate new foliage. As plants grow, monitor for pests or diseases, as young plants can be more susceptible. Once the risk of frost has passed and the plants have developed a robust root system and several leaves, they can be gradually acclimated to outdoor conditions. This hardening-off process involves exposing them to increasing periods of outdoor light and temperature before transplanting them to their final garden location.