Types of Palo Verde Trees

Native Palo Verde Species

• The two desert native species of palo verde are the blue palo verde (Parkinsonia floridum) and foothills palo verde (Parkinsonia microphylla). Both of these trees have thorns. The blue palo verde is hardy in Sunset zones 10, 12 and 13, withstanding temperatures as low as 10 degrees F. The blue palo verde has a vase shape and sculptural quality to its form. The leaves have a bluish tinge, and it is the first to burst into bloom in the early spring. This tree grows to 30 feet tall and wide.

  The foothills palo verde grows best in lower zones, and is hardy in Sunset Zones 12 and 13, to 15 degrees F. It tends to be a little scrubbier than the blue palo verde, with leaf color leaning toward olive green. The foothills variety blooms after the blue palo verde. It is a small tree, growing to about 10 to 20 feet tall and wide.

Hybrid Palo Verde Species

• The Desert Museum palo verde, Parkinsonia hybrid "Desert Museum," is hardy in Sunset zones 10, 12 and 13. It is a cross between the blue, foothills and Mexican palo verde. This hybrid was bred for a longer lasting flower show, producing blooms from March through May. Another bonus is that it is thornless. This tree is upright in form, with sculptural branches and attractive lime-green bark. It grows fairly quickly to about 25 feet tall and wide.

  The palo brea (Parkinsonia praecox) is hardy in Sunset zones 12 and 13, to 25 degrees F. It is a sculptural tree from Northern Mexico, reaching to about 25 feet tall and wide with an attractive umbrella form. The yellow flowers appear in late spring. It has small thorns.

Non-native Palo Verde

• The Mexican palo verde (Parkinsonia aculeata) is considered a weed tree as it has invaded the desert, coming up wherever there is sufficient water. It is short lived, thorny and messy, dropping leaves and needles. It is the last palo verde to bloom in spring, and has pale yellow flowers.

Watering Palo Verdes

• Palo verdes are drought tolerant, but look better with supplemental irrigation. Without sufficient water, they will go drought dormant and drop their leaves. Watering deeply every two weeks, especially in the hot months of May and June, will ensure they stay green.