Question: I would be grateful if you could give me some information about Ailanthus trees aka "Tree of Heaven" because it grows so fast. There is one approximately three metres from my house and I am afraid its roots will damage our foundations.
Answer: There isn’t anything heavenly about the roots of Ailanthus. Although the foliage and flowers are attractive, in many countries, the tree is considered an invasive species. The roots of any tree are likely to spread in a radius wider than its height, so for a tree of heaven, the ideal planting distance from a building would be 25m.
Houses built on shrinkable clays are more at risk from damage tree by roots in the area than those on a sandy soil. There are so many variables associated with tree roots that it is not easy to predict whether there will definitely be damage caused, but three metres is too close for all but the smallest specimens. Tree of heaven tends to send up suckers, so can be a problem in gardens from this aspect too.
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