Parkinsonia microphylla
little-leaved palo verde
Overview
Parkinsonia microphylla is a slow-growing deciduous desert tree in the pea family, reaching 10-25 feet (3-7.5 m) tall and 10-20 feet (3-6 m) wide, with a short trunk and a dense, intricately branched crown. The bark and twigs are green to yellowish-green and carry out photosynthesis, which lets the tree keep producing food after it sheds its leaves in drought. The bipinnate leaves are tiny, with minute leaflets that fall during dry spells and after flowering. Branch tips taper to stiff spines. Pale yellow flowers about 0.5 inch (12 mm) across, with one cream to white banner petal, open in late spring, mostly April to May, in loose clusters. Flat seed pods 1-3 inches (2.5-7.5 cm) long follow and constrict between the seeds. It grows on rocky desert slopes and washes of the Sonoran Desert and acts as a nurse plant for young saguaro. Growth is slow and the wood is brittle, so branches can break in storms.
Native Range
Parkinsonia microphylla is native to the Sonoran Desert of southern Arizona, southeastern California, and northwestern Mexico, including Sonora and Baja California. It grows on rocky slopes, bajadas, and desert washes.Suggested Uses
Used as a small shade tree, specimen, or screen in desert and xeriscape gardens on well-drained soil. The spring flowers draw bees, and the seeds feed birds and small mammals. Space trees 15-20 feet (4.5-6 m) apart to allow the crown to spread.How to Identify
Appearance
Size & Dimensions
Height10' - 25'
Width/Spread10' - 20'
Reaches mature size in approximately 15 years
Bloom Information
Pale yellow flowers open in late spring, mostly April to May, a few weeks after the related blue palo verde. Bloom lasts about 2-3 weeks and varies with winter rainfall. Flat constricted pods ripen through early summer.
Detailed Descriptions
Flower Description
pale yellow with cream bannerFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 8-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grows in full sun on lean, rocky, sharply drained soil with a pH near 7.0-8.5, and tolerates intense heat and prolonged drought once established. It drops its leaves in dry periods to conserve water, relying on green bark for photosynthesis. Excess water and rich soil produce weak, fast growth and shorten the tree's life. It needs little to no supplemental irrigation in desert climates and no routine feeding. Hard frost below about 15F (-9C) damages young growth.Pruning
Prune in late spring or summer to remove dead, crossing, or low branches and to lift the canopy. The wood is brittle, and heavy pruning can leave stubs that die back. Removing large areas of green bark reduces the surface the tree uses for photosynthesis.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
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D
late springsummer