This Q&A pretty well sums up my feelings about this mail order promoted tree.
Q: I have three Austree hybrid willows that are 9 years old and 40 to 50 feet tall. These trees are very high-maintenance, and the root system is approaching the sidewalk, driveway and house. Roots also are growing on top of the ground. Grass does not grow well under them, but they provide minimal shade. Should they go? R.B., Flower Mound
A: Yes, they are horrible trees. That's why I recommend avoiding them. Cut your losses and cut them down. I doubt they would even make good firewood. If you want willows, plant weeping willows. Better choices for fairly fast-growing trees include bur oak, Mexican sycamore, Texas red oak, dawn redwood and Montezuma cypress.
‘Austrees’ or ‘Australian Willows.’ According to the Rocky Mountain Austree website the Austree Hybrid is the ‘result of 30 years of selective breeding’ in New Zealand. They point out that these trees are used for ‘conservation, noise and dust barriers, shade trees, hedges, privacy screens, windbreaks, and erosion control.’ They also note that, ‘the hybrid vigor of this tree is substantial.’
Austree is a cross between Hankow or Pekin willow (Salix matsudana) and white willow (Salix alba). The white willow is native to North America and the Hankow willow is native to China and Korea. Usually when plant breeders create a hybrid it’s with the goal of combining the best characteristics of each parent. However, both parents are willows and neither of these has much to brag about.
Extremely fast growing trees like these willows tend to have a multitude of problems. They have weak wood that is prone to breakage from wind or ice. They’re subject to attack by aphids, woodborers, wood rot, and canker diseases. They’re also messy.
Like all willows, Austree is very short-lived. Its effective life expectancy is about twelve to fifteen years. Like other willows, the Austree is susceptible to numerous canker diseases which can significantly shorten its life expectancy. It’s also very important to keep in mind their invasive roots.