Tree · Sonoran native
Blue Palo Verde
Parkinsonia florida · Fabaceae
Also called: Blue Paloverde
Blue Palo Verde (Parkinsonia florida) is a low-water tree native to the Sonoran Desert region well suited to Tucson and the low desert. It grows to 25-30 ft H x 25-30 ft W in full sun, with a fast growth rate. Expect bright/golden yellow blooms spring.
Blue Palo Verde at a glance
- Water use
- Low (established)
- Sun
- Full sun
- Mature size
- 25-30 ft H x 25-30 ft W
- Growth rate
- Fast
- Bloom
- Bright/golden yellow, Spring (March-May), peaking in April; may rebloom after summer rains.
- Cold hardiness
- Hardy to about 10-15 F; USDA zones 8-11.
- Soil
- Tolerates a wide range including poor, rocky, alkaline, and clay soils; needs good drainage and tolerates caliche. Naturally found in washes with deeper soils.
- Native range
- Sonoran Desert of Arizona, California, and northwest Mexico (Sonora, Baja California); typically along desert washes and floodplains.
- Best used as
- Shade tree, Specimen/accent tree, Desert/native landscape, Wash and revegetation plantings, Street/parking lot tree with adequate space
- Wildlife
- Nectar and pollen source for native bees and butterflies; seeds eaten by birds, rodents, and javelina; provides nesting cover and acts as a nurse plant for cacti such as saguaro.
- Toxicity
- Not considered toxic to humans or pets; seeds were historically eaten by Native peoples.
How to grow Blue Palo Verde in Tucson & the low desert
Watering
Drought tolerant once established; in Tucson, water established trees deeply every 2-4 weeks in summer and monthly or less in winter to maintain vigor and reduce limb dieback. Deep, infrequent irrigation encourages a strong root system.
Fertilizer & nutrients
Generally needs no fertilizer; as a nitrogen-fixing legume it supplies much of its own nitrogen. A single light spring nitrogen application can speed establishment of young trees if growth is slow.
Pruning & care
Prune in late spring or summer after flowering and after the cold season; remove crossing or weak limbs and elevate the canopy gradually. Avoid heavy pruning, which stimulates weak watersprouts; never top the tree.
Notes
Arizona's state tree. Distinguished by blue-green bark and twigs and larger flowers than Foothill Palo Verde; green photosynthetic bark lets it photosynthesize even when leafless. Drops leaf and twig litter and has thorns at the nodes. Blooms about two weeks earlier than Foothill Palo Verde.
Sources: University of Arizona Cooperative Extension; Arizona-Sonora Desert Museum; AMWUA Landscape Plants for the Arizona Desert; Tohono Chul / Tucson Botanical Gardens