Pronounciation: Plum-BA-go a-u-ri-cu-LA-ta
Sunset 8, 9, 12-24
Landscape Use: Accent, background, raised planters, cascade effect. Used as in landscapes from maritime coastal southern and central California to the lower deserts of Arizona as a sprawling and informal accent shrub.
Form & Character: Arching and spreading, unruly and informal.
Growth Habit: Evergreen herbaceous to semi-woody shrub, sometimes vigorous and sprawling to 6 feet with 10 feet spread. The white flowering cultivar 'Alba' is less vigorous.
Foliage/texture: Oblong-spatulate, 2 inches long tapering to a short petiole, stipular leaves and semi-angular stems; medium texture.
Flowers & fruits: Powdered blue tubular flowers in terminal clusters, mostly powder blue, fruit insignificant.
Seasonal color: Flowers from March to December, heaviest in late summer and early autumn.
Temperature: Tolerant, but high heat fades flower color from powder blue to whitish blue.
Light: Full sun to partial shade. Eastern exposures best, avoid western exposures.
Soil: Iron chlorosis in alkaline soils is common in Phoenix.
Watering: Control growth rate by extending the interval between irrigations. Copious added water encourages vegetative growth at the expense of reproductive growth (more water = less flowers ).
Pruning: Prune to shape, do not try and maintain this plant as a formal hedge. Frequent shearing diminishes bloom potential and will only frustrate those who expect conformity in the natural world.
Disease and pests: None
Additional comments: Cape plumbago was once a popular landscape shrub in the later half of the 20th century. Nowadays, it's popularity in Phoenix has waned like a pair of 'red ball jets' sneakers. It's important to note the potential size of this sprawling, cascading shrub - it's rather large. It is not suited for use in small areas without extensive pruning maintenance which will reduce floral display if done improperly. Cultivar 'Alba' has white flowers, while 'Royal Cape' and 'Imperial Blue' have sky blue flowers. In Phoenix, the present day emphases on 'desert landscaping' and water conservation means that colorful plants such as cape plumbago are 'out of style'.