The Cushion Bush (Leucophyta brownii or Calocephalus brownii) is a striking ornamental plant known for its distinctive silvery foliage and dense, cushion-like form. Its unique texture and bright, almost white appearance create visual contrast, adding year-round interest to any landscape.
Understanding the Cushion Bush Plant
Native to the coastal regions of southern Australia, including Tasmania, the Cushion Bush is a perennial shrub also known as Silver Bush or Wire Netting Bush. It grows as a compact, rounded shrub, typically reaching 1 to 3 feet in height and width. Its silvery-grey foliage features tiny, scale-like leaves tightly pressed against woolly stems, creating a fuzzy texture. This plant is highly tolerant of drought, salt spray, and wind, reflecting its coastal origins.
Caring for Your Cushion Bush
Light Requirements
The Cushion Bush thrives in full sun, which is essential for vibrant silver foliage and a compact form. While it tolerates partial sun, insufficient light can lead to leggier growth and reduced foliage density. At least six hours of direct sunlight daily is ideal for optimal health.
Watering Needs
Once established, the Cushion Bush is highly drought-tolerant. Overwatering can lead to root rot, so well-draining soil is crucial. Water deeply but infrequently, allowing the soil to dry out completely between waterings. Young plants may need more consistent watering during hot, dry spells to establish their root systems.
Soil Preferences
The Cushion Bush requires well-draining soil, performing best in sandy or rocky substrates. It tolerates poor, nutrient-deficient, and alkaline soils. Avoid heavy, water-retentive soils like clay, as they can cause root problems. Excellent drainage is paramount for the plant’s health.
Temperature and Humidity
Cushion Bush prefers warm, dry conditions and is hardy in USDA zones 9 to 10, thriving between 68°F and 95°F (20°C to 35°C). It tolerates light frost down to 20°F (-6°C), but prolonged freezing temperatures can cause damage. High humidity is not ideal and can increase susceptibility to fungal issues.
Pruning Techniques
Minimal pruning is needed for the Cushion Bush, as it naturally maintains a compact, rounded shape. Pruning is primarily for shaping, removing dead or damaged stems, or encouraging bushier growth. Light tip-pruning of young plants promotes a denser form. Avoid hard pruning into old, woody stems, as the plant does not respond well.
Fertilization
Adapted to poor soils, the Cushion Bush does not require regular fertilization. Over-fertilization can harm the plant. If growth appears stunted, a light application of a balanced, slow-release fertilizer in spring can be considered for young or newly planted specimens. Established plants thrive without supplemental feeding.
Planting and Landscape Uses
The Cushion Bush is a versatile plant for various landscape applications. It excels in rock gardens, coastal gardens, and xeriscapes due to its drought and salt tolerance. Its silvery foliage provides striking contrast with green plants, making it an excellent accent or border edging. It also grows well in containers. Proper spacing of 1 to 2 feet (30-60 cm) allows for its mature spread.
Common Challenges and Solutions
The Cushion Bush can encounter issues, primarily related to environmental conditions. Root rot is a common problem from overwatering or inadequate soil drainage; ensure well-draining soil and water only when completely dry. Frost damage can occur in colder climates; protect plants with a cover or move container specimens indoors during severe cold.
Legginess, characterized by elongated stems and reduced foliage density, indicates insufficient sunlight. Relocate the plant to a sunnier spot with at least six hours of direct light daily to restore its compact form. While resistant to pests, grey mold can occur in overly humid conditions. Improve air circulation and avoid overhead watering to prevent fungal problems.