Newberry, like most areas in the south, is home to many dogwood trees providing the landscape with beauty throughout the year.
During the spring, the blooms are beautiful.
In summer, the foliage is attractive.
In fall, the leaves are red.
In winter, without foliage, the tree enhances our landscapes with its beautiful branching form.
Dogwoods, like many trees in our landscapes, are exhibiting signs of drought stress. According to S.C. State Climatology Office, Newberry County is currently in a moderate drought.
Dogwood trees do not develop a deep root system and are, therefore, subject to rapid depletion of soil moisture.
In the wild, dogwood trees thrive growing under the canopy of hardwood and pine trees where they are sheltered from the scorching sun.
In the landscape, dogwood trees prefer growing under larger trees that provide shade.
However, many dogwoods in Newberry are planted in full sun and are exhibiting drought stress far more than those planted in the shade.
In order to preserve moisture, the stomata on the underside of the leaves will close thereby reducing loss.
The trees will even drop leaves to reduce its need for water.
Brown and dry leaf edges indicate leaf scorch.
This appears to be a disease problem to some, but it is actually due to drought stress.
While it is impossible to irrigate dogwoods in the woodland setting, we may irrigate in our home landscapes. Use a soaker hose or sprinkler to water trees thoroughly.
When using a soaker hose, place it at the drip line area and water for 8 hours in order to completely wet the depleted root system. Trees will need water at a rate of one to two inches each week until normal rainfall returns.
A two to three inch layer of mulch under the tree out to the drip line will help conserve moisture from rain and irrigation. This will also deter weed growth. Grass growing under dogwoods will deplete moisture and is thus, not advisable.
Winter hardiness is also reduced in trees that suffer from drought stress.
Drought stressed dogwood trees are more susceptible to disease and insect damage.
Powdery mildew is favored when areas with poor air circulation experience damp, cool nights and dry, warm days. This fungal disease is identified by the white powder that coats the upper leaf surface.
The leaves may show marginal leaf scorch along with reddish discoloration, dead patches, and early defoliation. This is commonly seen in the late summer.
Spot anthracnose occurs when humidity is high and rain is frequent. Spots appear on the flower bracts and then on the leaves.
Two other common leaf spot diseases in dogwoods are Cercospora and Septoria. The leaf spotting that occurs due to these fungi is common during wet summers.
Cleaning fallen debris, pruning infected limbs, and improving air circulation via selectively pruning the canopy will help decrease the risk of these fungal diseases. Fungicides are also available. Remember to always follow the label when using fungicides.
Insect damage to dogwood trees is usually minimal unless the tree is planted in full sun without adequate water. Trees may be seriously damaged by insects when drought stressed. Severe infestations may require insecticides. If insecticides are deemed necessary, follow the label.
The dogwood borer is the larva of a moth. It is five-eighth inch long, cream colored, with a reddish-brown head. It gets into the tree via an opening in the bark such as one created by mowers and string trimmers.
Once inside the bark, it feeds on the cambium and eventually may kill the tree.
Dogwood club-gall midge is a fly about one-sixteenth inch long. Its larva hatches, enters the shoot, and causes a gall to form on the stem. In fall, the larva will exit the galls and over winter. A deformed, wilted leaf is a symptom of this insect’s presence.
Scales look like little bumps and feed by piercing and sucking. The immature form, crawlers, are susceptible to insecticides but the adults are protected by their covering.
Trees that are properly maintained will be able to withstand some insect and disease problems. Dogwoods prefer moist, sandy or loamy, fertile, slightly acidic, and well-drained soil.
If your landscape does not have at least one specimen, locate a desirable area and plant one. It will provide years of year-round beauty.
The Newberry Master Gardener Association is grateful to all those who participated in another successful year at the Newberry Farmer’s Market. Thank you buyers, venders, presenters and non-profits.