Bone Plant, scientifically known as Isocoma menziesii (Menzies’ goldenbush or Coastal goldenbush), is a resilient shrub valued for its unique appearance and adaptability. Its sturdy, stiff stems contribute to its common name. This plant thrives in challenging conditions, making it a low-maintenance choice for various garden settings.
Understanding the Bone Plant
Isocoma menziesii is a perennial subshrub native to California and Baja California. It grows in coastal and inland habitats like chaparral and salt marshes, favoring sandy soils. This shrub typically reaches 0.4 to 2 meters (1.3 to 6.5 feet) tall and can spread up to 1.5 meters (5 feet) wide, forming a matted or rounded bush.
Its gray-green leaves are spatulate-oblong, 1-3 cm long, and often clustered. They can be hairy and may have slightly lobed edges. The plant produces numerous small, yellow, daisy-like flowers in compact clusters throughout summer and fall, sometimes extending from spring into winter. These late-season blooms provide a valuable nectar source for pollinators, including butterflies and bees.
Bone Plant Care Essentials
Menzies’ goldenbush thrives in full sun, needing at least six hours of direct sunlight daily for robust growth and abundant flowering. While it can tolerate some partial shade, especially during the hottest parts of the day, consistent sun yields the best results. The plant adapts to various soil types but performs best in well-draining, sandy, or rocky soils, mimicking its native habitat. It tolerates a wide pH range and can grow in moderately saline conditions.
Once established, Menzies’ goldenbush is drought-tolerant, needing minimal water. Watering every two to three weeks with a deep soak is generally sufficient. Avoid excessive moisture, as the plant is susceptible to root rot in overly wet conditions. It is hardy in USDA zones 8-10. Fertilization is generally not necessary, but a balanced, slow-release formula can be applied during the growing season if desired.
Propagating and Pruning Bone Plant
Menzies’ goldenbush can be propagated through seed or stem cuttings. For seeds, collect achenes when fully mature, typically November to December. No special pre-treatment is generally needed, and germination often occurs in winter with adequate rainfall. Sow seeds on the soil surface and lightly cover them for good soil contact.
For stem cuttings, select healthy, non-flowering shoots during active growth. Cuttings should be 4-6 inches long, taken with a sharp, clean tool. Applying a rooting hormone can increase success. Plant cuttings in a well-draining, sandy growing medium, maintaining consistent moisture, warmth, and indirect light until roots establish.
Pruning Menzies’ goldenbush maintains its shape, promotes health, and encourages denser foliage and more blossoms. The best time to prune is late winter to early spring, just before new growth begins. If the plant becomes too tall after spring growth, trim it before summer blooms.
Remove any dead or damaged branches, and trim back about one-third of the plant’s growth or older stems to encourage bushiness. Use sharp, clean tools and make cuts above an outward-facing bud or node. Avoid excessive trimming.
Addressing Common Bone Plant Concerns
Menzies’ goldenbush is robust and resistant to most common pests and diseases, making it a low-maintenance choice. However, improper care can lead to issues. Root rot is a common problem due to excessive moisture or poorly draining soil. Ensuring well-draining soil and minimal watering once established can prevent this.
While resilient, the plant may experience flower withering or branch blight. Prompt removal of affected parts with clean tools can help manage this. Its appearance can also change seasonally; it may be semi-deciduous in summer, and extreme cold or intense heat can cause wilting, browning, leaf scorch, or stunted growth. These responses are often temporary, and the plant usually recovers with appropriate conditions.