Palo Brea (Cercidium praecox) remains one of the most popular and sought after trees in the arid landscape palette. This popularity is based on the tree's unique natural beauty. Displays of bright yellow flowers in spring, smooth green trunks and branches and sculptural, graceful branches combine to make Palo Brea the centerpiece of many arid landscape designs. It has no significant insect pests but can be seriously damaged by over irrigation and cold weather. Published studies on planted Palo Brea indicate that it is hardy to about 20 degrees F. In landscape plantings they survive typical winter weather in the deserts of central Arizona and southern California with little or no damage.

When growing in containers above ground, C. praecox 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 e winter months following injury. In the Spring when temperatures stimulate bud break, evidence of injury (brown discoloration of the trunk and/or branches leading to cracking and splitting of the bark) appears on damaged trees.

Trees like Palo Brea, 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 temperature, heat retention provided by other plants, and the proximity of building and streets. Transplant shock associated with unusually cold weather may also play a role in winter losses of Palo Breas. Loading, shipping, unloading and planting puts stress on all trees. Under non-winter conditions, arid region trees recover rapidly and resume growing. In winter some Palo Breas do not recover from these stresses as they otherwise would.

Because it is impossible to accurately determine which of our Palo Brea Trees have sustained winter damage, Arid Zone Trees has a policy of not releasing this tree for sale during the winter months if we have temperatures below 28 F. We offer this information in the hope that it will help you make informed decisions on the most appropriate and economical use of this remarkable tree. We continue to evaluate new seed sources for all the arid species we grow to find selections that provide greater adaptation to the range of conditions found in the desert southwest.