Austrees are hybrid willows, the result of a cross between white willow and Pekin willow. White willows are native to North America; Pekin willows are from China.
Pekin willow and its close relative, the globe willow, are marginally hardy in the Denver area, but thrive on the Western Slope if given sufficient water.
These trees have many of the same disease and insect problems associated with most poplars and other willows. After a dry, cold winter, willows may show extensive dieback. They often develop cytospora canker, bacterial wetwood and other stress-related diseases. Other problems include winter sunscald, storm damage, aphids and fall webworm.
Some soil conservation districts in Colorado recommend Austrees because of their fast growth, erosion control, shelterbelt and windbreak value. Austrees are successful for these purposes as long as their water supply is not limited and other problems can be minimized or tolerated.
Willows in urban landscapes may have a longer list of faults than attributes. In addition to insect and disease problems, willows have vigorous, invasive root systems which may clog sewer lines. They are "messy" trees, regularly dropping leaves and twigs. Other than their trait of growing quickly, most willows offer little ornamental landscape value. In addition, fast-growing trees generally have short lives, weak wood and are susceptible to storm damage.
In urban areas, where special care can be extended to a wider variety of plant choices, depend on your local nursery or garden center to supply well-adapted landscape plants.
For more information, see the following Colorado State University Extension fact sheet(s).
- Bacterial Wetwood
- Environmental Disorders of Woody Plants
- Cytospora Canker
- Aphids on Shade Trees and Ornamentals
- Oystershell Scale
- Shade Tree Borers
- Fall and Winter Watering
- Large Deciduous Trees
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Updated Tuesday, November 19, 2013