The Arizona ash (Fraxinus velutina), also known as velvet ash, is a pretty, lush, deciduous native shade tree that does well in our climate. In the Tucson area, it’s native habitat is riparian, so it prefers a bit more water than other native trees such as mesquite. It’s a beautiful tree for fall color, as well, and has low allergenic potential. It’s also fairly fast-growing, particularly if watered deeply on a regular basis. It's a great candidate for a grey water or rainwater basin.
The compound leaves of this tree are a pretty, deep green, and it has an interesting gray bark texture. When choosing a spot for it, make sure it’s in a place where the leaf drop doesn't bother you. Female trees also drop winged seed pods, so it can be a bit messy. It also tends to grow roots along the surface, so it would be wise to plant it in areas where it can’t damage any hardscaping such as sidewalks and driveways.
The Arizona ash grows up to 50 feet or so in our climate, so make sure it’s far enough away from power lines, as well. The trees can live up to 50 years if well-cared for, but if it develops issues it may only live 20-25 years.
The Arizona ash is well-adapted to our desert soils and even does well in rocky areas. It can take full sunlight, but make sure you do not prune the branches too high — too much sunlight on the trunk can cause a sunburn on the bark, called sunscald, which results in damage to the tree. For this reason, it’s not a good tree for areas with reflected sun. In other parts of the country with humid weather it can develop fungal diseases, but this is rare in our area. Arizona ash is hardy to at least 0 F, being native here up to 7,000 feet.
The tree is native to the desert southwest of the U.S. as well as northern Mexico. It exhibits a lot of variety when grown naturally from seed, and you may find different horticultural varieties in local nurseries. Fantex and Modesto are some of the varieties available for residential landscapes.
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