Prosopis thornless glandulosa 'AZT' Thornless Honey Mesquite 'AZT'
Prosopis glandulosa thornless ‘AZT’ Thornless Honey Mesquite is a clonally propagated, thornless selection of P. glandulosa. with its willow-like appearance, delicate leaf canopy and grayish sculptural trunk. The characteristic that sets this ‘AZT’ clone apart from seed selections are the S-shaped branching structure , the trees synchronous bud break, uniform growth and the absence of thorns. In landscape settings, 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 ‘AZT’ Thornless Honey Mesquite 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 day length deciduous (shedding leaves and going dormant is response to the shorter days of fall and winter) in winter with new leaves emerging in late February and early March in the Phoenix 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 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.
Thornless Honey Mesquites are ideal for pedestrian intense environments like streetscapes, park plantings and commercial and residential landscapes or re-vegetation of disturbed desert sites. The form and texture of this Mesquite blend almost seamlessly with surrounding native Sonoran Desert trees and shrubs. Easily incorporated into urban landscapes and increasingly being used in more formal or traditional landscape designs, they are used as theme trees along streets, commercial projects, as screens, windbreaks or barrier plantings or as transition trees back to native species.
Cultural Practices:
Wind damage and uprooting are the products of poor pruning, staking practices, and improper irrigation and should not be considered as inherent, unavoidable horticultural shortcomings of Prosopis species. 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 transplanted trees. Irrigation emitter arrangement along with other information about planting and irrigation practices for desert trees can be found at Irrigation Practices for Desert Trees and Tree Planting Practices an Overview.
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 retains 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, thrips, 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 phytotoxcity. Always read label and follow label instruction before using pesticides. For pesticide control recommendations contact a licensed pest control advisor.