Carpenteria californica — Bush Anemone
Carpenteria californica, or bush anemone, is one of California’s loveliest, but rarest, shrubs. It is native only to dry granite ridges of the southern Sierra Nevada foothills in the Central Valley near Fresno and is the only species in its genus. ‘Elizabeth’ is the most available (if not the only) cultivar and is prized for its larger flowers that could be mistaken for an exotic tropical plant rather than a California native that grows untended in an isolated area of the Sierra.
Under ideal conditions, this erect, evergreen shrub can grow 5-6 ft. tall and 3-5 ft. in diameter. Its thick, oblong, 3-4-in. long leaves are glossy, dark green on top and whitish on the bottom, making a striking backdrop to the shrub’s showy white, fragrant 2-in. flowers that resemble camellias. From May through July, these loose clusters with as many as 20 blooms at the end of branches are a spectacular sight. In keeping with its common name, the shrub has flat, anemone-like petals which encase dozens of bright yellow stamens. Its fruit contains seeds in a leathery, cone-shaped pod.
Like most natives, Carpenteria californica is best planted in fall. It prefers a sheltered site with high, dappled shade and filtered sun. Despite its charm, it can be somewhat temperamental if not given good drainage in light soil with no fertilizer added; planting in a raised bed or on a gradual slope is preferable. Because this California native comes from a habitat where summers are long, hot and dry, it can survive on very little water once established; however, inadequate watering may result in slower growth and fewer flowers.
The first year after planting, irrigate enough to keep roots moist—two or more deep waterings per month, more in hot, inland valleys. If planted in spring when the plant is in bloom and most beautiful, deep water once a week and then let the soil dry out between times, being sure to use plenty of mulch. Once the plant is established, cut back on the frequency, so that the top couple inches of soil become fairly dry between irrigations. This native may need less or no water near the Sonoma coast. It is best to use drip irrigation, as overhead watering can cause fungal problems on the foliage. More bush anemones perish from over-watering than from lack of moisture.
Bush anemones usually maintain an attractive rounded form, but may become sprawling and rangy with inadequate water or extreme heat. If pruning is needed to shape or restrain growth, cut back to lower buds after flowering for a fuller looking plant. Unfortunately, hard pruning older branches may not stimulate new growth. Because stems are not self cleaning, leaves wither but do not fall naturally to the ground; they may easily be stripped off in late summer.
If carpenteria develops a sticky honey dew, blackish sooty mold or whitish cast skins and/or its leaves curl and distort, the probable cause is aphids. Inspect new growth regularly and hose off aphids forcefully with water. Bush anemone can withstand normal Sonoma winters, but could sustain damage from continued low temperatures or a late spring frost. Although it is considered deer resistant, foliage is sometimes slightly damaged.