Tree
African sumac
Searsia lancea · Anacardiaceae
Also called: Willow rhus, Karee, Karree
African sumac (Searsia lancea) is a low-water tree well suited to Tucson and the low desert. It thrives in full sun, with a moderate to fast growth rate. Expect greenish-yellow (not ornamental) blooms Inconspicuous small yellowish-green flowers in late winter to spring.
African sumac at a glance
- Water use
- Low (established)
- Sun
- Full sun; tolerates reflected heat.
- Mature size
- 20-25 ft tall and 20-30 ft wide; rounded, weeping evergreen canopy with willow-like leaves.
- Growth rate
- Moderate to fast
- Bloom
- Greenish-yellow (not ornamental), Inconspicuous small yellowish-green flowers in late winter to spring; dioecious (separate male and female trees).
- Cold hardiness
- Evergreen and hardy to roughly 15-20 degrees F; reliably hardy in Tucson with little to no frost protection.
- Soil
- Tolerates a wide range of desert soils including alkaline, rocky, sandy, and caliche; needs reasonable drainage.
- Native range
- Native to southern Africa (South Africa, Lesotho, Botswana, Namibia). Synonym: Rhus lancea.
- Best used as
- Evergreen shade tree, Screen / windbreak, Patio and street tree, Erosion control
- Wildlife
- Provides dense evergreen cover and nesting habitat; small fruits on female trees are eaten by birds.
- Toxicity
- Generally low toxicity, but in the Anacardiaceae (cashew/poison ivy family) the sap can cause skin irritation or allergic dermatitis in sensitive individuals.
How to grow African sumac in Tucson & the low desert
Watering
Drought tolerant once established; deep-water roughly every 2-3 weeks in summer and monthly to less in winter. Deep infrequent irrigation that wets the full root zone encourages deep roots and a more stable, drought-hardy tree.
Fertilizer & nutrients
Low requirements. An optional light application of a balanced or slow-release tree fertilizer in spring supports growth; usually not needed in established trees. Iron chelate corrects occasional chlorosis in alkaline soil.
Pruning & care
Train to a single or multi-trunk form when young and thin the canopy to reduce wind resistance and 'sail' effect. Prune in late winter/early spring; remove crossing and weak limbs to build strong structure.
Notes
Tough, fast evergreen shade tree for Tucson, but female trees produce abundant small berries that drop, stain hardscape, and reseed readily, creating volunteer seedlings; it is considered weedy/potentially invasive in the low desert. Choose male (fruitless) selections to avoid litter and seedlings. Shallow roots can lift pavement, and dense canopies should be thinned to reduce wind throw.
Sources: University of Arizona Cooperative Extension; Arizona Department of Water Resources / AMWUA low-water tree lists; Arid Zone Trees grower references; Pima County Master Gardeners