Prosopis thornless glandulosa 'AZT' ('AZT' Thornless Honey Mesquite)
Foliage: Deciduous
Mature Height: 25’ - 35’
Mature Width: 30’ - 40’
Growth Rate: Moderate to Fast
Hardiness: 0 degrees F
Exposure: Full Sun
Leaf Color: Dark Green
Shade: Filtered to Dense
Flower Color: Greenish-Yellow
Flower Shape: Fuzzy Spike
Flower Season: Late Spring
Thorns: No
Propagation Method: Cloning
Sizes Available: #25, #45, & 48"
Prosopis glandulosa thornless ‘AZT’ exhibits characteristics very similar to the P. glandulosa with its willow-like appearance, delicate leaf canopy and grayish sculptural trunk. The characteristic and main attraction that sets this ‘AZT’ clone apart from seed selections is the S-shaped branching structure that is thornless, the trees synchronous bud break and uniform growth. In the landscape setting, the tree grows at a moderate to fast rate to a mature height of 25’ to 35’ and 30’ to 40’ wide. The weeping leaf gives this tree an appearance similar to the California Pepper. The leaf canopy is spreading and lacy providing ample filtered shade that supports the growth and flowering of under-story planting. When used as accent trees or as individual specimens, trees are typically pruned up to highlight the graceful twisted, multiple trunk structure. Honey mesquites are photo deciduous in winter with new leaves emerging in late February and early March in the Phoenix, Arizona metropolitan area. The Honey Mesquite is the first mesquite to break bud in the springtime. In addition, with this clones synchronized bud break, the showy early spring foliage is an attractive glossy, bright chartreuse green. Elongate, greenish yellow, fragrant flowers 2” to 3” long begin appearing in March and may be seen as late as September. Flowers produce narrow, bright red to tan seed pods in summer. The trees grow best in full sun and well draining soils. They are hardy to 0 degrees F. making ideal landscape trees in areas (like southern Nevada) where extreme winter temperatures can damage other mesquite species.
These thornless trees make them ideal for landscape applications from re-vegetation of disturbed desert sites to streetscapes, park plantings and commercial and residential landscapes. The form and texture of the ‘AZT’ Thornless Honey Mesquite blend almost seamlessly with surrounding native Sonoran desert trees and shrubs.
They are easily incorporated into urban landscapes and are increasingly being used in more formal or traditional landscape designs. They are used as theme trees along streets and commercial projects, as screens, windbreaks or barrier plantings, as transition trees back to native species in revegetation projects or any landscape applications where ample shade is desired.
Variety 'AZT':
Arid Zone Trees makes selections from thousands of trees propagated from seed. Only Individual trees having the most desirable physical qualities (branching habits, leaf color, leaf canopy, and flower color) and sound horticultural characteristics (rooting, cold hardiness and growth rate) are selected for further study. These trees are then cloned (vegetatively propagated) and planted at our nursery for evaluation. Only the best of these trees are then placed in cloning production and are designated Variety 'AZT'. Since no one single selection of any desert tree specie is best adapted to all landscape applications, we continually search for new additions to our Variety 'AZT'.
Prosopis glandulosa thornless 'AZT' is propagated and available exclusively from Arid Zone Trees.
Cultural Practices:
Wind damage and uprooting are the products of poor pruning and staking practices and improper irrigation and should not be considered as inherent, unavoidable horticultural shortcomings of Prosopis hybrids. Foster the development of a more dispersed root system and reduce the risk of wind throw by arranging irrigation emitters at varying distances from the trunk to encourage roots to "seek out" water and nutrients. Frequent watering is needed to promote good terminal growth on newly planted trees. Irrigation emitter arrangement along with other information on irrigations practices for desert trees can be found at Irrigation Practices for Desert Trees.
Prune as needed to reinforce the structure and form of the tree. Periodic thinning is the most desirable method of pruning. Pruning to remove about 20% of the canopy during the growing season helps promote root development that is proportional to the shoot growth of young trees. Removing more than 20% of the canopy can inhibit rooting, lead to sunburn injuries that can later be invaded by wood boring insects, and encourage undesired re-growth made up of dense flushes of branches and leaves. Selective pruning should be used to promote the development of a symmetrical canopy with well spaced branches. Avoid hedging or heading back desert species, as this will only stimulate excessive branching. Use tree stakes only when absolutely necessary and then only briefly. Select low-breaking, upright trees as they occupy no more space than a single-trunk specimen yet retain the natural wind resistance of trees found growing native in desert settings. Always use clean, sharp tools that are cleaned regularly in a 10% solution of bleach. For detail pruning guide see Pruning Desert Trees.
Periodically insect pests can be a problem on some desert trees. On young trees, insect infestation can slow typical seasonal growth. Inspect trees during the growing season for common garden sucking insects such as aphids, thrip, whiteflies or psyllids. During dry months, (May and June) in dusty conditions, spider mites can appear. Monitor for infestation and apply controls as needed. Spray applications of water or water and Safer Soap give short-term control (3 to 7 days) for small insect population. For heavy infestation or longer control use federally registered insecticides. A contact insecticide application will kill existing adults. An application with a systemic soil drench will provide 8 to 12 weeks control for any post application insect hatchings or migration of insects. Before using pesticide for the first time or on new plants or cultivar, treat a few plants and check for phytotoxicty. Always read label and follow label instruction before using pesticides. For pesticide control recommendations contact a licensed pest control advisor.
The information provided here was gathered from research literature published by the University of Arizona, other professional landscape and horticulture organizations and our experience at Arid Zone Trees. Always consult local landscape experts for recommendations for your specific area.