I would like to plant fast-growing shade trees of medium height (no taller than 50 feet). Are willows a good choice? If not, what should I grow?
Arnold Hecker, Ravenna, NE
Richard Sutton, associate professor and landscape architect at the University of Nebraska in Lincoln, replies: Laurel willow (Salix pentandra) might be a good choice, but first let me caution that fast-growing trees typically have weak wood and may drop their branches in the early spring snowstorms that are not uncommon in Nebraska. In general, fast growth and strong wood are mutually exclusive qualities in trees. I would recommend the following: go ahead and plant a fast-growing tree, but also plant a slow-growing shade tree 20 feet away on the sunny side of the fast-growing one. Regularly prune the weak crotches out of the fast-growing tree. In 15 or 20 years, should you still be gardening at that location, remove the fast-growing tree. You will have had the fast shade you needed while the stronger, more desirable tree matured.
Fast-growing trees that should work well for you include laurel willow, river birch (Betula nigra), hybrid poplar (Populus canadensis ‘Nor’Easter’), Siberian elm (Ulmus pumila), and box elder (Acer negundo). Slow-growing trees I would recommend include any of the nonseed-producing cultivars of green ash (Fraxinus pennsylvanica), thornless honey locust (Gleditsia triacanthos var. inermis), hackberry (Celtis occidentalis), and burr oak (Quercus macrocarpa).