Scientific: Aloidendron barberae (Synonyms: Aloe bainesii, Aloe barberae)
Common: tree aloe
Family: Asphodelaceae (formerly Xanthorrhoeaceae)
Origin: Subtropical coastal forests, ravines and dry valleys of South Africa northwards to Mozambique.
Pronounciation: A-lo-i-DEN-dron bar-be-RAY-ee
Hardiness zones
Sunset 12 and 13 with protection, 16-24
USDA 9-11
Landscape Use: In Phoenix, tree aloe is a great accent or focal point plant for mixed canopied xeric gardens with some full western sun protection, large containers.
Form & Character: Strongly upright, stiff, arborescent with age, striking, imposing, enormous, sculptural, neat and clean.
Growth Habit: Evergreen, succulent, herbaceous to semi-woody perennial that is arborescent in habit growing slowly to 50-feet tall, although usually much shorter in Phoenix due to the extreme summer heat.
Foliage/texture: Rounded, terminal rosulates (rosettes) of glaucous to dark green, strap-shaped leaves to 2-feet long, often recurved downward, margins armed with pale, blunt dentate spines, senescent leaves not persistent; coarse texture.
Flowers & fruits: Rose pink flowers on elongated, branched stalks clustered in 20-inch long racemes, strongly attract hummingbirds; fruits are a multicarpulate capsule, generally unattractive.
Seasonal color: Brilliantly-colored, spectacular pinkish flowers during winter and spring.
Temperature: Tree aloe is cold hardy to 30oF, and suffers heat damage when summer temperatures exceed 112oF. Its cardinal temperature range is between 55o and 85oF.
Light: Partial sun to high filtered or building shade in Phoenix to full sun along coastal California. Protection from intense western summer sun in Phoenix is required.
Soil: Tolerant, provided soil is well drained.
Watering: Infrequent irrigations during winter depending frequency of winter rains, but regular irrigations will be needed during summer for survival in Phoenix.
Pruning: None, except removal of senescent flower stalks and leaves.
Propagation: Seed or stem cuttings (allow to dry for several days prior to directly sticking into substrate).
Disease and pests: None if cultured outdoors. Aphids, mealybugs or scale if cultured indoors or in a greenhouse.
Additional comments: Tree aloe is rarely seen in Phoenix. Placement of tree aloe in the landscape must make provisions for its ultimate large stature once mature - "many years down the road".
Taxonomic tidbit: Tree aloe was first collected and submitted for classification by Mary Elizabeth Barber (1818-1899), who was a notable 'plant, bird, and bug' collector in the former Republic of Transkei in South Africa.