Canna lilies, with their vibrant blooms and lush foliage, bring a tropical feel to any garden. These striking plants are related to bananas and ginger. Propagating canna lilies allows gardeners to increase their plant collection, save money, and share these beautiful plants.
Propagating Canna Lilies by Rhizome Division
Rhizome division is a common method for propagating canna lilies, ensuring new plants are identical to the parent. The ideal time is late winter or early spring, before new growth, or in the fall after foliage dies back in colder climates. Gardeners in colder regions (USDA Zones 7 and below) often dig up rhizomes in the fall for overwintering indoors, which is an ideal time for division.
Dig up the rhizome clump from the ground or its container. Gently shake or rinse off excess soil to expose the rhizomes and their growth points, often called “eyes.” These eyes are small bumps or nodes from which new shoots will emerge. Each section you divide needs at least one healthy eye and some roots for successful growth.
Use a sharp, clean knife or shovel to divide the rhizomes, ensuring each piece is viable. Some gardeners prefer to break rhizomes apart by hand if easily separable. After cutting, allow the cut surfaces to dry and form a protective callus for a day or two before planting; this helps prevent rot. Plant divided sections horizontally about one to two inches deep in prepared soil, with the eye facing upwards.
Propagating Canna Lilies from Seed
Growing canna lilies from seed is a slower process and may not yield plants identical to the parent. Canna seeds have a hard outer shell that requires preparation for water to penetrate and initiate germination. This process, known as scarification, breaks or weakens the seed coat.
Scarification involves nicking the seed coat with a nail clipper or file, or rubbing it with sandpaper until the lighter inner part is visible. After scarification, soak the seeds in warm water for 24 to 48 hours, or even up to a week, to further soften the coat and encourage germination.
Sow prepared seeds indoors about six to eight weeks before the last expected frost, planting them 0.25 inches deep in a seed-starting mix. Maintain a consistent soil temperature of 70 to 75 degrees Fahrenheit (21-24°C), which can be achieved with a heating mat. Ensure the soil remains consistently moist but not waterlogged. Once seedlings emerge, provide ample light. When seedlings are several inches tall, they can be transplanted into larger pots or directly into the garden after all danger of frost has passed.
Caring for Newly Propagated Canna Lilies
Proper care is important for the successful establishment and growth of newly propagated canna lilies. Consistent moisture is necessary, especially for new divisions and seedlings, as they require water to develop strong root systems. While cannas thrive in moist conditions, well-draining soil is important to prevent waterlogging and rot.
Ensure newly planted cannas receive at least six to eight hours of direct sunlight daily. Rich, fertile soil is beneficial; amend the planting area with compost or well-rotted manure for nutrients. Once growth is established, a balanced, slow-release fertilizer can be applied.
Protecting young plants from extreme weather and pests is important. Young canna plants are vulnerable to environmental stressors and may benefit from initial shelter. Regular monitoring for common garden pests helps address issues.
Common Canna Lily Propagation Challenges
Gardeners may encounter several challenges during canna lily propagation. For seeds, a lack of germination is a frequent issue, often due to the hard seed coat if scarification or soaking steps are skipped or inadequate. Incorrect temperature or inconsistent moisture can hinder germination.
When dividing rhizomes, rotting can occur if cut sections are not allowed to callus before planting, or if the soil is too wet and lacks adequate drainage. Overwatering newly planted divisions can lead to rot. Ensuring the soil is moist is important.
Slow growth in newly propagated plants can be due to insufficient light, inadequate nutrients, or improper planting depth. Cannas need full sun and rich soil to thrive; planting rhizomes too deep can stunt growth. Young canna plants are susceptible to common pests such as aphids, spider mites, or leaf rollers. Early detection and action protect these plants.