Isocoma menziesii
coastal goldenbush
Coastal California and Baja California
Overview
Isocoma menziesii is a low, bushy evergreen subshrub of the California and Baja California coast, growing 1-4 feet (30-120 cm) tall and about as wide from a woody base. Its green leaves are resinous and sticky, variable in shape from narrow and toothed to lobed, and clothe many branching stems. From late summer into fall the stem tips carry flat-topped clusters of small yellow flower heads made up of disk florets without showy rays. I. menziesii grows on coastal bluffs, dunes, sandy flats, and in coastal sage scrub, where it tolerates wind, salt spray, drought, and lean soils. It stays green through the mild coastal winter and resprouts after browsing or light fire. The plant can look coarse and weedy outside its bloom season, and it spreads by seed into disturbed ground. Some plants in the genus carry compounds toxic to livestock, so caution is warranted where animals graze. It is hardy in USDA zones 9 through 11.
Native Range
Native to the Pacific coast of California and into Baja California, Mexico. It grows on coastal bluffs, dunes, sandy flats, and in coastal sage scrub, generally within reach of ocean influence.Suggested Uses
Planted in coastal native gardens, dune and bluff restoration, and low-water landscapes within its mild-winter range. Its late bloom supports pollinators, and its salt tolerance suits exposed seaside sites.How to Identify
Appearance
Size & Dimensions
Height1' - 4'
Width/Spread2' - 4'
Reaches mature size in approximately 2 years
Bloom Information
Flat-topped clusters of small yellow flower heads open from late summer into fall, generally August through November. The rayless heads draw bees, butterflies, and other late-season pollinators along the coast. Small tufted seeds follow and disperse on the wind.
Detailed Descriptions
Foliage Description
GreenGrowing Conditions
Sun Requirements
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow I. menziesii in full sun and sandy, fast-draining soil; it tolerates salt spray, wind, drought, and poor ground near the coast. Water only to establish young plants, after which it needs little or no irrigation. It grows quickly and can look untidy, so cut it back in late winter to keep a denser shape. The plant self-sows into open soil and suits naturalized coastal plantings more than formal beds. It carries few pest problems in its native range. Rich soil and frequent water produce weak, floppy growth.Pruning
Cut the stems back by about half in late winter or early spring to maintain a compact, leafy mound. Remove dead or storm-damaged stems as needed. Light shearing after bloom tidies the plant and limits self-sowing.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
winter