UT
researchers are barking up the dogwood tree!UT
researchers are barking up the dogwood tree!By Tina Jones
Although the dogwood is not Tennessee's state tree, it still plays
a very important role. Tennessee nurseries grow more dogwoods than any other state (about
75% of all dogwoods produced) and have been doing it for more than one hundred years. The
yearly wholesale value of dogwoods in Tennessee is between $30 and $40 million. The
dogwood is not just an important part of Tennessee's economy. Wildlife
and birds also depend on the dogwood for food and shelter.
With so many people and animals counting on dogwoods for their livelihoods, it's easy to
see why researchers like Dr. Mark Windham and Dr. Robert Trigiano
and members of the Dogwood Anthracnose Team at the University of
Tennessee Agricultural Experiment Station became worried when a lethal disease called dogwood anthracnose began killing thousands and thousands of
dogwood trees across the United States.
Before the blossoms appear.
There are approximately 40 species of dogwood (Cornus sp.) in the world. Most people think the colored part of the dogwood
is the blossom, but it isn't. The colored leaves are actually called bract and merely
serve as a protective covering for the flower buds enclosed in the center. Blossoms that
appear in the spring actually developed the summer before and spent the winter nestled
inside the bract. The blooms in the spring indicate the beginning of the dogwood tree's
reproductive cycle.
Dogwood blooms. The pink petals of this plant are called "bracts" and are not
really the bloom at all. The tiny yellow flowers in the center are the blossoms that will
eventually produce berries and seed.
The actual blossoms that produce dogwood seeds are a crown of greenish-yellow florets in
the center of the bracts. Just like some flowers , dogwoods may
need bees and other insects for pollenation. Bract color can range from white to pink
to an almost red color.
The flowering dogwood C florida has a natural range from
Ontario to Mexico, east to Florida and north to Massachusetts. C. nuttalli is a
taller Pacific dogwood that grows from British Columbia (Canada) to northern California.
(Agri-Science p.47) In the northeastern U.S. the dogwood is a shorter tree while in the
south it can grow to 40 feet tall. The normal size of a dogwood is 20 to 25 feet. People
living in the south will start to see blooms in March while those in the north see blooms
in June.