What’s Wrong With My Dogwood Tree?
What if the cat being chased by the dog ended up climbing a dogwood tree? If it knew it was a dogwood
tree, would it prefer another tree instead? I’m sure the cat is just happy to be safe. There is a dogwood
tree still growing alone in the front yard of the first house I lived in. I picture it as a small tree, because
that is how I remember it. Now, it is a large, lonely dogwood – one that probably provides safe escape
for many neighborhood cats.
The dogwood is a very recognizable tree in South Georgia and is adaptive to many different soil types. It
likes well-drained soils high in organic matter. You do not see dogwoods growing in poorly-drained soils
in woods environments. They need good soil drainage and protection from drought.
We usually see the best results from dogwoods planted in association with larger trees that provide
moderate shade. Dogwoods like partial shade. In the wild, the dogwood is commonly found as an
understory tree growing under hardwoods and pines. Growth problems are more likely in hot, dry
exposures.
I have answered quite a few questions concerning dogwoods in the past few weeks. Issues described to
me concern dogwoods that appear to be struggling. Each time I drive to a location to look at dogwood
problems, I see dogwood trees in others’ lawns that are experiencing the same symptoms. Leaves are
showing signs of chlorosis (yellowing) and necrosis (burning at the tips.) Additionally, some are covered
in leaf spots.
The first thing we considered is a common disease. Dogwoods frequently get a disease called Spot
Anthracnose. The symptoms are reddish-purple spots on the leaves and flower bracts. We see Spot
Anthracnose in the spring when flowers appear. We also observe Cercospora leaf spot in microscope
samples. This is found on many ornamental plants and flowers. It turns out, these leaf spots are normal
and are not the primary problem.
This conclusion lead to one other diagnosis. Weather conditions this summer have proven to be
sporadic with rainfall, though dry conditions predominately have existed. I have discussed this matter
with UGA Extension Pathologist Dr. Elizabeth Little in a few conversations over what I believe is mostly
environmental stress.
Dr. Little says, “The die back of the new growth and the leaf loss is probably environmental. I have been
seeing drought-like stress issues on dogwoods in the last month. It could be the rapid switch we had from
a long period of cooler and wetter to very sunny and hot caused more drought stress damage than one
would expect, especially on the younger foliage but all over the trees as well. The amount of stress will be
site-specific and some trees may be more vulnerable than others. Weak trees with poor root systems will
get more problems.”
In conclusion, we are seeing environmental stress on dogwoods right now. This is not only observed in
Thomas County, but also much of the rest of the state. Dr. Little works in UGA’s Pathology lab and
diagnoses pathogens on ornamental plants and turfgrass. The sporadic temperatures and rain events
have also played a role in Leyland cypress problems existing at this time.
As we move into September, check flower bugs on your dogwood trees. We can get an idea of the
flower load during this time. Those that produce an abundance of flowers followed by a heavy berry crop will produce less flowers the following season. Also, dogwoods in heavy shade produce fewer
flowers than those in more sunlight.