Flowering dogwood trees, belonging to the genus cornus, grow widely across North America. These attractive trees grow to an average height of 30 feet and usually spread even wider. They are highly valued as ornamental trees due to their overall appearance and the abundant flowers that bloom in both spring and fall. There are two main varieties of dogwood that display the familiar white flowers.
Eastern Flowering Dogwood
The eastern flowering dogwood or cornus florida is native to the eastern half of the United States and Canada. The foliage is light green in spring maturing to a darker green by the end of summer. The various shades of red and purple that the leaves take on in the fall make the tree stand out in any landscape. Cornus florida has a number of other common names including white dogwood and American boxwood. The eastern flowering dogwood is the official state tree of Virginia.
The Pacific dogwood or cornus nuttallii is indigenous to the Pacific Northwest and is very similar to its eastern cousin. The most easily observed difference from the eastern flowering dogwood is the much deeper green foliage that turns orange in the fall. The flower of the Pacific dogwood is the floral emblem of British Columbia, and the trees are a protected species in that province.
Dogwoods prefer partial shade and high humidity, conditions that simulate their natural forest setting. They are classified as understory trees, thriving between the forest canopy and the undergrowth. Ideally the forest floor beneath the dogwood trees is rich in decaying humus that both feeds and acidifies the soil. This explains why these trees respond so well to mulching in a residential environment.
Dogwood Tree Care
Although dogwoods usually get enough water from rainfall, they may need hand watering during dry spells. If well mulched, the trees will be well fed and should not need fertilizer. Prune off dead wood in the fall to allow the tree to focus energy to the growing tips. This will also encourage more blooms. Always protect the delicate trunk of the dogwood against damage from lawn equipment such as mowers and trimmers. Trunk injury will weaken the tree and make it susceptible to insect infestations.
While many people admire the flowers of the dogwood, most don`t realize that they are not seeing flowers at all. The visible white petals are actually bracts, modified leaves that surround the true flower hidden within. When observed closely, the real flowers of the eastern flowering dogwood are greenish-yellow. But even though dogwoods really don`t have white flowers, they will continue to be a popular choice with landscape designers and gardeners alike.