Q.Invasive Angel Trumpet Tree roots
My neighbor planted a single tree that has multiplied to a total of five thru far. The roots are coming through the weep holes and beneath a retaining wall that separates our property. The wall is showing signs of pressure damage and I have been removing the roots and “sucker” trees that develop in my yard.
If the trees are cut down, what needs to be done to prevent the roots from continuing to grow?
Thank you for all assistance!

What I found is for Brugmansia suaveolens, white angel's trumpet. If you treat freshly cut stumps/suckers with concentrated glyphosate, using a foam paintbrush, it shouldn't come back. (If you live near a water source, you must use an herbicide rated safe for waterways.) However, you may kill the main, or parent, shrub as well.