Planting Space Along Sidewalks
Trees usually have one of two root types, either they have deep taproots or they have lateral, fibrous roots. Trees with deep taproots send their roots deep within the earth to seek out water and nutrients. Trees with fibrous, lateral roots spread their roots horizontally near the soil surface to absorb rain runoff from the tree’s canopy. These lateral roots can grow quite large and heave up heavy cement sidewalks. From the other perspective, concrete over these roots can prevent the roots from receiving rainwater, oxygen, and other nutrients that trees need for survival. Therefore, it’s not a good idea from either perspective to plant shallow rooting trees too close to sidewalks. The height at maturity of trees also depends on what kind of root system a tree will have and how much room the roots will need to develop properly. Trees that grow 50 feet (15 m.) or less make better terrace trees because they are less likely to interfere with overhead power lines and also have smaller root zones. So how far from the sidewalk should you plant a tree? The general rule of thumb is trees that grow up to 30 feet (9 m.) should be planted at least 3-4 feet (1 m.) from sidewalks or concrete areas. Trees that grow 30-50 feet (9-15 m.) tall should be planted 5-6 feet (1.5-2 m.) from sidewalks, and trees that grow more than 50 feet (15 m.) high should be planted at least 8 feet (2.5 m.) from sidewalks.
Planting Trees Near Sidewalks
Some deep-rooted trees that can grow near sidewalks are:
White oak Japanese lilac tree Hickory Walnut Hornbeam Linden Ginkgo Most ornamental pear trees Cherry trees Dogwoods
Some trees with shallow lateral roots that should not be planted near sidewalks are:
Bradford pear Norway maple Red maple Sugar maple Ash Sweetgum Tulip tree Pin oak Poplar Willow American elm
