Palo Verde

Parkinsonia spp

Many native desert plants have yellow blooms, but when Palo Verde trees are in bloom they provide a spectacular display. Once established, the trees don’t require supplemental water to survive, but water will accelerate growth.

Flowers: J F M A M J J A S O N D
Status: Native
Origin: Varies by species
Family: Fabaceae (Leguminosae)
Size: Varies by species
Sun: Full
Watering: None after established. Supplemental irrigation greatly increases canopy density.
Growth Rate:
Soil: Tolerant of a variety of soil types
Temperature:
Pruning: Because of their inherent shrub-like growth habit, blue palo verde trees have a moderate to high pruning requirement. Pruning strategies include selective crown thininng (especially when young) to create a strong schaffold branch architecture and raising the crown base height to give the tree a more “urban friendly” tree form.
Disease and Pests: Larvae of palo verde root borers (Derobrachus geminatus)
Uses: Nesting habitat for birds, great nectar plant for native bees
Notes: Serve as nurse plants to young saguaros

Foothill Palo Verde and Blue Palo Verde

In 1954, the State of Arizona named the Palo Verde as its State Tree. The legislature did not distinguish between the two species of this tree that are native to the State; therefore both the Foothill and the Blue share the honor.

Both the Blue and Foothill Palo Verdes have a number of characteristics in common, starting with the reason they are called Palo Verdes (Spanish for green stick). The name indicates that these trees can use the chlorophyll in their bark to photosynthesize and produce sugar. In general, three quarters of their food is metabolized through the bark, whereas only a quarter is produced by the leaves.

The Arizona Native Plant Society

Blue Palo Verde (Parkinsonia florida)

Upright growth habit and wide spreading crown, growing to 30′ tall. First Palo Verde to bloom in spring. Great shade tree.

Foothills Palo Verde (Parkinsonia microphylla)

Also known as the Little Leaf Palo Verde, this is a shrubbier and slower growing species of Palo Verde. Blossoms are pale yellow with a delicate fragrance. Each branch ends in a thorn, so keep away from walking areas. Hardy to 20 degrees F. Moderately slow growth to 15′.

Palo Brea (Parkinsonia praecox)

Also known as the Sonoran Palo Verde, this tree has smooth blue-green bark and a sculptural look. Grows to 35′ and makes a great focal point in large spacious desert landscapes. Brilliant yellow flowers color the entire tree and the ground beneath. Hardy to 20 degrees F.

Mexican Palo Verde (Parkinsonia aculeata)

This tree reseeds readily and can become a problem in the landscape; don’t plant close to natural preserves or waterways. Rapidly grows to 30′ tall. Invasive in Phoenix. Be sure to wear gloves when pruning as the tips of its stipular spines readily break off and infect skin.

Desert Museum Palo Verde (Parkinsonia x ‘Desert Museum’)

A three way hybrid between the Blue, Foothills and Mexican Palo Verdes, created by researchers at the Arizona Sonoran Desert Museum. This hybrid takes attributes from each of its parents, including rapid growth, strong upright branching and large showy flowers that bloom over a long period of time. Disease and pest resistant, no spines and few seed pods, but has a reputation for weak branches.

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