Invasive trees should be removed when young. Seedlings can often be found dispersed randomly throughout the landscape, but more often they appear in large clusters. Norway maple seedlings grow beneath and in the area of the parent tree, while Ailanthus altissima, tree-of-heaven seedlings cluster in large stands generally at some distance from the mother tree.
One option for removing seedlings where mowing isn’t practical, try uprooting large cluster with a squeegee.
Often insects will help to kill off invasive plant species. Learn to recognize beneficial biocontrols.
For more information click the following pages: