Cercidium Praecox has become an extremely popular landscape tree. The sculptural qualities of the lime green branches and the beautiful display of bright yellow flowers in the Spring account for this popularity. Sonoran Palo Verde or Palo Brea as they are commonly called, are often chosen for streetscapes, as accent trees and as individual specimens in entry monuments. The Palo Brea’s native growing area is on the desert plains from Sonora and Baja California, Mexico, to Venezuela and Peru.

Drought tolerance is another attribute of this tree. Once these trees are established and reach acceptable size, they require little or no irrigation other than natural rainfall. Arid Zone Trees has many of these trees in a streetscape that has not received any irrigation except for rainfall for over four years. This tree can in fact be damaged or killed by over irrigation or excessive rainfall, when planted in poorly drained soil conditions.

Published studies on planted Palo Brea indicate that it is hardy to about 20 degrees F. In landscape plantings they survive typical winter conditions in the Tucson, Phoenix and Palm Desert, CA areas with little or no frost damage. This tree during winter, when in containers above ground, appears more prone to frost injury, over watering, and winter transplant shock. Nursery boxed Palo Breas may be injured anytime winter temperatures drop below 28 degrees F. Dormant, boxed Palo Breas may appear normal during the winter months following injury. In the Spring when temperatures stimulate bud break, evidence of injury (brown discoloration of the branches leading to cracking and splitting of the bark) appears on damaged trees.

Trees like Palo Breas, that are grown from seed have a built-in level of genetic diversity that shows up as varying levels of hardiness. The hardiness of this tree is also influenced by the maturity of the tree, duration and intensity of low temperatures, heat retention provided by other plants, and the proximity to buildings and streets. Transplant shock may also play a role in winter losses of Palo Breas. Loading, shipping, unloading and planting put stress on all trees. Under non-winter planting conditions trees recover rapidly and resume growing. In winter some Palo Breas do not recover from these stresses as they otherwise would.