Cherry trees (Prunus species) make attractive additions to many yards and gardens. In the spring, a liberal covering of pink blossoms enlivens a landscape just beginning to green up. As the year wears on, tasty fruits take the place of the blossoms and provide a food source for birds, wildlife and people. Like all trees, cherry trees need water, which they draw up through their roots.
The roots of your cherry tree absorb water and, with it, dissolved mineral nutrients. The outer layer of root cells, called the epidermis, begins the process by absorbing water. Water moves next into the cortex and then passes into the tree's vascular system, where evaporation of water from the leaves pulls the water absorbed into the roots up the tree and into the leaves. Tiny fibers called root hairs greatly increase the surface area available for absorbing water.
Cherry trees have another ally in obtaining water: special fungi called mycorrhizae. These fungi colonize the roots of cherry trees, penetrating into the cortex between root cells and spreading through the soil around the tree, where they absorb water for the tree in exchange for sugars produced in the tree's leaves.
Most cherry trees have a low, spreading root system. Descriptions provided by the U.S. Forest Service indicate that, in many species, the roots do not delve much deeper than a foot into the soil. Instead, the root systems spread far from the tree. For example, the bitter cherry (Prunus emarginata) grows roots that extend up to 50 feet from the tree. The chokecherry -- a species that grows as a large shrub or small tree -- is a notable exception: Its root system may plunge 6 feet deep.
Your tree's root system helps to determine the tree's water needs. Cherry tree roots don't like to be constantly wet, so the Virginia Cooperative Extension recommends planting them only in well-drained soil. Because the roots spread so wide and close to the surface, they absorb water quickly, and the cherry tree withstands drought conditions better than most fruit trees, according to the extension. However, watering during dry spells improves fruit production.
Cherry trees will send up root suckers, clones of the parent tree that arise from its root system and compete with it for water and nutrients. Root suckers often spring up from injuries to the parent tree's roots, and because the cherry root system grows so shallowly, you should take special care to avoid injuring the roots with a lawn mower.