Tree · Sonoran native
Catclaw Acacia
Senegalia greggii · Fabaceae
Also called: Catclaw, Gregg Catclaw, Wait-a-minute Bush, Devil's Claw Acacia, Una de Gato
Catclaw Acacia (Senegalia greggii) is a very low-water tree native to the Sonoran Desert region well suited to Tucson and the low desert. It thrives in full sun.
Catclaw Acacia at a glance
- Water use
- Very Low (established)
- Sun
- Full sun.
- Mature size
- 10-20 ft H x 10-20 ft W (often a large multi-trunked shrub; can reach ~25-30 ft as a tree on deep soils).
- Growth rate
- Slow.
- Bloom
- Pale creamy-yellow, fragrant catkin-like (cylindrical) flower spikes., Late spring into summer (April-June, sometimes again after summer rains).
- Cold hardiness
- Very cold hardy for a desert legume; USDA zones 7-10, tolerating roughly 0-10 F. Winter deciduous.
- Soil
- Well-drained native desert soils—rocky, sandy, decomposed-granite, and caliche/alkaline soils all suitable; excellent for unimproved sites.
- Native range
- Native to the Sonoran, Chihuahuan, and Mojave Deserts—throughout most of Arizona (along washes, slopes, and bajadas), plus CA, NV, NM, TX, UT, and northern Mexico.
- Best used as
- Native/wildlife habitat tree or large shrub, Naturalistic and revegetation plantings, Barrier or security hedge (thorns), Light filtered shade, Honey/bee plant
- Wildlife
- Outstanding pollinator and wildlife plant—a major nectar source for native bees and butterflies (larval host for several butterflies), and seeds/pods are eaten by birds, quail, and small mammals; dense thorny canopy provides cover and nesting.
- Toxicity
- Not significantly toxic to humans; the recurved thorns are the main hazard and can cause scratches and snagging injuries.
How to grow Catclaw Acacia in Tucson & the low desert
Watering
Extremely drought tolerant once established (deep taproot); needs little to no supplemental water—occasional deep soaks in the hottest months speed growth, but established plants thrive on rainfall alone in Tucson.
Fertilizer & nutrients
None needed; as a nitrogen-fixing legume it makes its own nitrogen and grows in poor desert soils. Fertilizer is unnecessary and can cause weak, lanky growth.
Pruning & care
Prune in late winter/early spring to lift and shape into a small tree or to remove deadwood; minimal pruning otherwise. Wear heavy gloves and long sleeves—the recurved 'catclaw' thorns grab clothing and skin.
Notes
Reclassified from Acacia greggii to Senegalia greggii. A tough, low-water native for naturalistic and wildlife landscapes; the hooked thorns make placement away from walkways important. Slow growth and deciduous winter habit are trade-offs for its extreme toughness.
Sources: Arizona-Sonora Desert Museum; University of Arizona Cooperative Extension; AMWUA Landscape Plants for the Arizona Desert; Lady Bird Johnson Wildflower Center; Southwest Desert Flora