Scientific: Bauhinia variegata
Common: purple orchid tree
Family: Fabaceae (Leguminosae)
Origin: China, India (naturalized across southeast Asia.)

Pronounciation: Bow-HEN-ee-a var-a-ee-GA-ta

Hardiness zones
13, 18-23
USDA 9-11

Landscape Use: A spring flowering accent or specimen tree for oasis-like landscape settings. Does not perform well in landscapes that have a predominance of inorganic rock mulch.

Form & Character: Upright, rounded, subtropical, Spanish or oriental architecture, vulnerable.

Growth Habit: Woody, semi-evergreen, perennial tree, briefly deciduous in early/mid spring, moderate to 20 to 35 feet height with equal spread.

Foliage/texture: Orchid trees have rounded light green two-lobed leaves, strongly emarginated, that are up to 3 inches wide. In Phoenix, the leaves age prematurely because of the high summer heat and usually become marginally necrotic during later summer and fall if they are not planted in mesic or green surroundings with plenty of supplemental irrigation. Purple orchid tree has a medium coarse texture.

Flowers & fruits: Orchid tree produces an intense array of large white, pink to purple tubular orchid-like flowers in terminal clusters while the tree is briefly deciduous during early spring; fruit is an elongated brown pod to 6 inches during summer.

Seasonal color: Flowers are displayed from early March through mid April.

Temperature: Heat-loving (except for those scorching Phoenix summer days when the air temperature rockets above 110oF), hardy to 22oF.

Light: Full sun to partial shade.

Soil: In central Arizona, desert alkaline soils will cause leaves to develop intervenal chlorosis caused by iron, zinc, and mangenese deficiencies. This is especially aggrevated by chronic wet soil conditions such as in lawns. Apply micronutrient fertilizers, especially those in chelated form, in early spring to correct this problem. Orchid tree performs best in soils covered with turf or organic-based mulches.

Watering: Apply water at frequent and regular intervals especially during the summer.

Pruning: Purple orchid tree needs pruning and staking when young to promote structural integrity and a strong scaffold branch system, elevate canopy base.....but don't raise the crown too high as trunk sunscald will occur!

Propagation: Cutting or seed

Disease and pests: None of significance. Local desert stressors on this tree are more from abiotic factors such as heat and drought.

Additional comments: Cultivar 'Candida' has white flowers. Orchid tree is an excellent small to medium size flowering accent tree that tends to look ragged and tattered when fruiting. Also, orchid tree sheds a moderate amount of liter, but the outstanding spring floral display easily compensates for the tree's otherwise moderate levels of litter. Orchid tree has somewhat smaller leaves and flowers compare with Bauhinia x blakeana (Hong Kong orchid tree).