Question
I'm planing on planting a royal empress tree in my garden, it would be planted about 20 feet from the pool that has a liner.
I was wondering if the roots of the tree will grow to damage the liner? Also how invasive is the empress tree? I live in Cape Cod
MA

Answer
The roots will be about 1 1/2 times the width of the foliage. 20 feet should be plenty of distance from the pool that the root will not cause any problems. This tree has a width of about 30 feet when mature which would mean 15 feet on a side. They also have a root structure that tends to extend downward, making them less of a potential problem in terms of disrupting underground piping or foundations. Their oversized leaves provide a great deal of shade.

Not an invasive as far as a yard tree. But since it grows fast and can spread by seed it is considered an invasive in the wild since it can grow fast and shade out natural plants. In a yard setting it is fine for shade.