What happened to my dogwood? -Washington Daily News

What happened to my dogwood?

Posted on Friday, March 10, 2023 at 12:32 pm

Their graceful prostrate branches with creamy white flowers mark the beginning of spring so beautifully. When I see them getting ready to bloom, I’m reminded that I have several calls about dogwood during the season. Many of them ask, “What happened to my Dogwood?” As usual, there is no short answer. By the way, these creamy white flowers are not actually flowers, they are modified leaves called bracts. Just in case you end up on Jeopardy, I thought you should know.

Dogwood is a wonderful tree in its native environment. They complement the forest understory and do not suffer from many of the stresses we subject them to in the home landscape. Growing on a lawn is not their native environment, it is a harsh reality they must adapt to in order to survive. Does this mean that we should not grow them – absolutely not! We always have to think: the right factory, the right place!

Dogwood adapts well to growing in slightly acidic, moist, well-drained soil. As a forest tree in the understory, it enjoys the protection from heat, cold, and harsh winds that larger, overstory trees provide. When we take such a plant and expose it to the sun, expose it to wind, heat and cold, it causes stress. Dogwood is not a long-lived tree, in ideal conditions it lives an average of about 80 years.

There are only a few diseases and insect pests that affect dogwood. The worst of which is dogwood anthracnose (Discula destructiva). The good news is that this disease is not commonly found in the coastal plains of North Carolina. Root rot often kills dogwood on the coastal plains. These are root rots from Phytophthora and Armillaria, which usually occur in soils that remain saturated or waterlogged for long periods of time. The only insect that will cause significant damage to dogwood is the dogwood borer (Synanthedon scytula). These holes can often be found near the base. The borer is the larva of a clear winged moth that resembles a small wasp. Borers will cause the decline of old trees and the death of young trees. Look for sawdust at the base to see if you have any holes. More often than not, it’s cultural issues, things we can prevent, that cause dogwood to die.

There are many cultural challenges that a tree growing in a lawn will face, further adding to these stresses. First, it’s the wrong fit. This is true for any tree I am called to look at. Homeowners and many landscapers plant trees incorrectly. When planting a tree, first prepare the site. This includes taking a soil sample and taking a long look at how the site drains. Next, find the first root on the tree, it should be planted no further than an inch below the soil surface. Dig a hole twice as deep and two and a half times as wide as the root ball on your new tree. Backfill the excavated soil until the tree is at the proper height (again, the first root should be no deeper than 1 inch below the soil surface). Now plant your tree, sprinkling the soil lightly around the roots. The soil should be lightly filled so that during rain water does not get on the upper part of the roots. Rain and irrigation serve to settle the soil over time. If you’re planting a tree that comes in a container, it’s important to check for and cut off any twisting roots. Trees grown in a nursery can be in pots for a long time. This can cause the roots to hit the side of the container and then grow in a circle. If these roots are not pruned before planting, they will continue to grow in this circular pattern until they eventually girdle the tree. This cuts off the supply of water and nutrients coming from the roots and kills the tree.

Mulch is always good, especially with dogwood. A good mulch ring two to five feet in diameter and two to three inches deep will serve many functions. It’s like a blanket for the roots in the winter and a conditioner in the summer. Mulch serves to moderate soil temperature, effectively minimizing the high and low seasons. This will conserve soil moisture by reducing evaporation. A good layer of mulch will reduce annual weed pressure and reduce turf competition for nutrients. Finally, mulch protects the tree from mechanical damage by keeping weed trimmers and mowers away from the trunk. However, like most things in gardening and life, it has to be done right. Adding mulch to the base of your tree, called volcanic mulch, has the opposite effect, often causing more stress than no mulch at all. It will slowly suffocate the tree! When spreading the mulch, be sure to keep it two to three centimeters away from the trunk.

Plant Dogwood in moist, well-drained soil in full shade to morning sun. Make sure to prune off dead and crossed limbs each year. Prune well to keep air moving through the tree. It helps to dry the tree after rain and heavy dew to reduce the disease. With a very shallow root system, Dogwood is very sensitive to drought. If it doesn’t rain for more than two weeks, don’t forget to water your tree. If you use a sprinkler, don’t let the water continuously hit the trunk of the tree, it will have the same effect as volcanic mulch! Follow these simple steps and watch your tree flourish.

The series “KNOW TO GROW” will be held every Friday from 9:00am to 11:00am throughout March. Please call the office for more information and to schedule a class.

If you have problems growing in your home landscape, please call the extension office at (252)946-0111 or email me at gene_fox@ncsu.edu. On Saturday, April 8, there will be a class on growing tomatoesthousand from 9:00 a.m. to 11:00 a.m. Make an appointment by phone. Save the date for April 15th at 9:00 a.m. for Extension Master GardnerSM Volunteers will host the annual vegetable sale. Until then, happy gardening!

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