This tender succulent subshrub is a native of Gran Canaria Island in the Canary Islands of the Atlantic Ocean. Also known as ‘Schwartzkopf’ and ‘Schwarzkopf’ meaning “black head’, it can be grown as a house plant where it is not hardy. Its leaves are dark purple to almost black when grown in full sun and form large terminal rosettes on long bare stems. In summer, mature stems produce racemes of star-shaped yellow flowers in their centers and then die down. The plant becomes semi-dormant until fall when it develops its darkest colored foliage. A. arboreum ‘Zwartkop’ tolerates salt and some drought so can be used in coastal plantings.
Type: Succulent, evergreen subshrub
Outstanding Feature: Dark purple rosettes formed by leaves
Form: Rounded mound
Growth Rate: Slow
Bloom: Yellow racemes of small star-shaped flowers in mid-summer
Size: 2-6.5’ H x 2-6.5’ W
Light: Full sun to part shade (best color in full sun)
Soil: Average, dry-moderately moist, well-drained
Hardiness: Zones 9-11
Care: Low maintenance
Pests and Diseases: Susceptible to aphids and mealybugs
Propagation: Cutting of leaf rosette (after callus as formed place in free-draining, gritty compost, and keep on the dry side until rooted.)
Karen Meyers