The genus Acacia has species distributed throughout the temperate and arid regions of the world. Many have gained popularity in arid landscape designs, including Acacia smallii, A. stenophylla, A. berlandieri and A. aneura. Two other species that are less well know but equally well adapted are Acacia schaffneri (Twisted Acacia) and Acacia craspedocarpa (Leather Leaf Acacia).

Twisted Acacia is native to the Chihuahuan desert of southern Texas and northern Mexico. Along with the common name Twisted Acacia, A. schaffneri is sometimes called Wheat's Acacia acknowledging the introduction of this specie into Phoenix landscapes by local landscape architect Jim Wheat. Its botanical name is derived from Wilhelm Schaffner a German dentist and botanist who settled in Mexico City in 1856. The finely divided leaves of this tree are set close together on short petioles that originate all along the branches. As a result of this unique leaf habit the gnarled and twisted branches appear fuzzy and lacy green beginning in early spring. This dense layer of leaves cover the small yet numerous thorns growing along the branches. Branches overlap and interweave to create an unusual canopy.

In spring, bright sulphur yellow, ball shaped flowers are borne, singly or in clusters densely along the branches (in a fashion similar to the leaves). Flowers are mildly fragrant. Trees mature to 15' to 25' tall and as wide with trunk calipers exceeding 12" in diameter. Twisted Acacia tolerates a wide range of soil types, thrives in full sun and is hardy to 17 F.

It has a moderate growth rate. Young trees will require pruning to achieve desired form. Once the mature form is established, little additional pruning is needed. The unorthodox leaf canopy and remarkable spring flower display make A. schaffneri an ideal specimen tree placed in a prominent place in the landscape. When used near walls, its woven branches cast intricate, lacy shadows and can be dramatically lit at night. The numerous thorns also make it an effective security barrier or perimeter planting. These trees have been used in streetscape settings, in plazas and in entry monuments.

Leather Leaf Acacia is an excellent, descriptive name for Acacia craspedocarpa, an Australian native that is used primarily as a large shrub or small tree in southwestern landscape designs. Its dense, upright branches form an erect, compact head that make it an ideal privacy/wide break shrub or as a background or foundation planting. Mature plants may reach 9' to 12' and be 6' to 8' wide.

Leaves are gray-green in color and slightly oval shaped with a densely netted veins on the unusually thick leaves. In spring individual, bright yellow, elongated puffball flowers are produced. Tan colored, flat, 2" long seed pods develop from the flowers. Leather Leaf Acacia is moderately cold hardy and grows well in full and partial sun. It will tolerate a variety of soils but does best in well draining soils.

Established plants are highly adapted to harsh summer conditions and can survive without supplemental irrigation. Watering once a month will insure limited growth but more frequent irrigation is needed to achieve optimal growth, appearance and flowering. A. craspedocarpa can be pruned to take the form of a small tree. Typically individual plant are used as a vertical shrub or planted in lines and sheared to form a solid hedge. This plant grows slowly and in some landscape applications it may be desirable to install larger container sizes (15 gallon to 24" box) to get more immediate impact.