Spike Leaf, or Cordyline australis, is an evergreen plant known for its distinctive appearance and adaptability. Also called Cabbage Tree or Cabbage Palm, it is a versatile and visually appealing choice for gardens, patios, and indoor containers in temperate climates. Its striking form and diverse foliage colors add unique texture and interest to any landscape.
Identifying Spike Leaf
Spike Leaf (Cordyline australis) is identified by its upright, palm-like structure. Young plants typically have a single trunk that can branch with age. Its foliage features long, sword-shaped leaves clustering at the branch tips. A notable identifying feature is the skirt of dead leaves that often forms around the trunk. While the species commonly has gray-green leaves, many cultivars offer colors like pink, red, purple, yellow, and variegated combinations. Young plants often display a fountain-like arrangement of leaves without a visible trunk, and are frequently sold as houseplants in this form.
Essential Growing Conditions
Spike Leaf thrives in full sun to partial shade. Brightly colored or variegated cultivars maintain their vibrant hues better in light to moderate shade, as direct sun can scorch foliage. Ideal soil is fertile, moist, and well-draining, with a slightly acidic pH (5.5-6.5). Incorporating organic matter improves soil quality and drainage.
These plants are hardy in USDA Zones 8-11, tolerating temperatures from 18 to 35 degrees Celsius. While they can withstand brief cold periods down to -5 to -10 degrees Celsius, prolonged frost can damage younger or colored foliage. They prefer 40-60% humidity; dry or drafty conditions can cause leaf loss. Outdoors, a sheltered position protects them from strong winds.
Ongoing Care and Maintenance
Proper watering is crucial for Spike Leaf plants. They prefer consistently moist soil but are prone to root rot if waterlogged. Allow the top inch of soil to dry between waterings to prevent overwatering, particularly for container-grown plants. Infrequent, deep waterings are more beneficial than frequent shallow ones.
Container plants require regular watering during the growing season, while ground-planted ones are more drought-tolerant once established. For vigorous growth, apply a balanced liquid fertilizer monthly from spring to late summer to container plants; ground-planted Cordyline australis typically do not need regular feeding. Repot container plants every two years in spring into a pot at least 20 percent larger to provide more room for root development and fresh nutrients.
Pruning Spike Leaf
Pruning Spike Leaf maintains its shape, removes undesirable growth, and encourages new development. This includes tidying the plant, managing its size, and eliminating dead, damaged, or diseased leaves. Older, lower leaves naturally yellow and die; these can be gently pulled or trimmed close to the stem to improve appearance.
For size reduction or to encourage branching, the main stem can be cut back. This “hard pruning” is best done in spring, after the last frost, as the plant enters active growth. Use sharp, clean pruning shears or a saw for precise cuts, which prevents disease and promotes healing. New shoots typically emerge just below the cut, and the plant will regrow.
Propagating Spike Leaf
Stem cuttings are an effective way to propagate Spike Leaf plants. Take a healthy stem section, ideally 6-8 inches long, with a few leaves at the top. Remove lower leaves and make a clean cut just below a node; this helps prevent rot and encourages rooting.
Cuttings can be rooted in a sand and soil mixture or directly in water. Maintain consistent moisture in the rooting medium and provide a warm, bright location away from direct sunlight. Spring and early summer are the best times for propagation, as the plants are actively growing and have more energy for root development. Another method involves separating suckers that emerge from the plant’s base and potting them individually.
Addressing Common Issues
Spike Leaf plants can encounter issues. Pests such as spider mites, mealybugs, aphids, and scale insects may infest foliage, particularly on indoor plants. These pests feed on plant sap, leading to yellowing or distorted leaves. Control methods include wiping leaves, regular misting, and applying insecticidal soap or neem oil for persistent infestations.
Environmental stresses also cause problems. Root rot, indicated by yellowing leaves and wilting, results from overwatering or poor drainage. Ensure well-draining soil and allow it to dry between waterings. Cold, damp winter conditions, drought, or heat stress can lead to leaf spots, browning, or poor growth. Provide winter protection, such as wrapping the plant or moving container plants indoors, to mitigate cold damage.