Of the more than 70 tropical and semi-tropical species of Caesalpinia, four (Caesalpinia cacalaco, C. gilliesii, C. mexicana and C. pulcherrima) are well adapted to landscapes in the desert southwest. The genus takes its name from Andreas Caesalpinia who was the chief physician to Pope Clement VII. These four species have in common spectacular flower displays, are adaptable to a variety of landscape uses from a mounding, rounded shrub to a small patio tree.

Of the Caesalpinia species, C. cacalaco and C. mexicana are most adaptable to being trained into patio tree form. In most landscapes they are used as accent, background plantings, in massings (to amplify the effects of the seasonal flowers) and as a border or streetscape planting. Hummingbirds and butterflies visit the blooms. They are all largely free of disease and insect pests and can subsist on limited irrigation. All grow best in full sun in well drained soils with moderate application of fertilizer. They can adapt to lawn and arid garden plantings. Optimum flowering is achieved with a combination of regular irrigation and fertilization.

Caesalpinia gilliesii (Yellow Bird of Paradise) has probably been used in desert landscapes longer than any of the other species. Like the others, it will grow as a mounding shrub to a height of 6' to 10' tall and as wide. This deciduous shrub is hardy to 10 degree F and fast growing. Shrubs can be pruned strongly when dormant to promote denser growth and maintain shrub form. It can be trained into a small tree but such specimens tend to have very dispersed canopies. Flowers are bright yellow with long red stamens that extend beyond the flower petals. Flowers are produced from spring through summer with the strongest displays in early summer. This species has naturalized in some desert locations and can survive on annual rainfall.

C. cacalaco (Cascalote, Mexican Bushbird) is a more recent addition to the desert landscape palette. It is characterized by sulphur flowers that appear in fall and winter, curved, rose-like thorns along the stems, semi-evergreen and hardy to 25 degrees. Flowers clusters appear at branch terminals and can be damaged by freezing temperatures. Foliage is fairly dense and dark green, contrasting sharply with yellow flowers. Stems are dark brown that thicken over time giving maturing specimens a vase shaped, graceful small tree form 10' to 15' tall and wide. It can also be maintained in shrub form by seasonal pruning.

C. mexicana (Mexican Bird of Paradise) can grow to become large evergreen to semi deciduous shrubs or small trees that are 10' to 15' tall and 6' to 12' wide. Flowers clusters are bright yellow, fragrant and appear at branch terminals from spring to fall. This specie is native to northern Mexico, growing in washes and slopes in arid regions. In the shrub form, they can be used as a screen, background shrubs and patio or court yard plantings for the tree forms. Mexican Bird of Paradise is fast growing, adapted to desert or tropical landscapes and is hardy to 20 degrees.

C. pulcherrima (Red Bird of Paradise) is by far the most popular and widely used of the desert birds of paradise. It is cultivated as a landscape plant in the tropics and subtropics. This deciduous shrub hardy to 25 degrees can grow from 6' to 10' tall and as wide. It has naturalized throughout the warmer parts of Mexico. Insufficient rain and low winter temp. may combine to prevent naturalization in Arizona. Young stems may have small, weak curved thorns. This attractive ornamental has bright orange and yellow flowers, with red stamens 2 to 3 times as long as the flower, produced from as early as April and as late as November. Red birds can be trained into small trees but do not have the visual impact of the pruned shrub form. Typically stems are pruned to within 6 to 12 inches above the ground, when the plant is dormant, to promote flowering and denser branching next season.