Trees that make surface roots or are shallow rooted are bad and those that love moist conditions, like willows, are the worst offenders. Here is a list of shallow rooted trees: Acer platanoides, Norway Maple Acer rubrum, Red Maple Acer saccharinum, Silver Maple Amelanchier species, Serviceberry Betula nigra, River Birch Cercis canadensis, Eastern Redbud Cotinus obovatus, American Smoketree Fagus grandifolia, American Beech Fraxinus americana, White Ash Fraxinus pennsylvanica, Green Ash Plantanus occidentalis, American Sycamore Populus species, Poplar or Cottonwood Quercus bicolor, Swamp White Oak Quercus palustris, Pin Oak Salix species, Willow Taxodium distichum, Common Baldcypress Thuja occidentalis, Eastern arborvitae Tsuga canadensis, Canadian Hemlock Ulmus americana, American Elm And a list of surface rooters: Norway maple Acer platanoides Red maple Acer rubrum Silver maple Acer saccharinum River birch Betula nigra Hackberries Celtis spp Beeches Fagus spp. Sweetgum Liquidambar styraciflua Southern magnolia Magnolia grandiflora London planetree Platanus x acerifolia American sycamore Platanus occidentalis Pin oak Quercus palustris Willow oak Quercus phellos Live oak Quercus virginiana Weeping willow Salix babylonica American elm Ulmus americana