View Mobile Site
 
Posted: November 16, 2013 7:35 p.m.

Trees in trouble?

Iconic magnolias may decline without attention

The nearly century-old magnolia trees that tower over Covington’s square, and help make it the icon it is, are healthy, but experts warn the trees could be in danger if their maintenance isn’t improved.

For years, some locals have warned about the damage done to the beautiful, flowering trees by the hundreds and thousands of people who walk, sit or lie down on the trees’ surrounding soil and root system during major events.

County landscape architect Debbie Bell said soil compaction is a very real concern, because compacted soil limits the ability of both water and oxygen to filter through and reach the root system, a tree’s life source. However, with the proper maintenance, including a few important things that have been neglected somewhat in past years because of budget cuts, Bell said the trees should be able to live for multiple decades to come.

Based on old photos — those that contain the trees and those that don’t, such as a 1907 postcard — Bell said the magnolias on the square are probably 85 to 100 years old. According to the Virginia Tech Dept. of Forest Resources and Environmental Conservation, magnolia trees have a maximum lifespan of 120 years.

Bell said the trees are healthy, but she said their health can decline rapidly if they don’t receive proper care. While there are metal support cables to support the trees’ sprawling branch systems, Bell said the trees have been lacking in pesticide treatment, soil aeration and the amount of mulch that covers their roots.

Root of a problem

A tree’s root system can spread out two to three times as wide as its branches, Bell said, and anyone who’s familiar with the square’s magnolia trees knows those branches cover a pretty wide area.

The larger, support roots are close to the tree, and the roots branch and thin out as they get farther from the tree. It’s the finer branches that pick up the nutrients, water and oxygen a tree needs to survive.

Bell said any activity of significance that takes place on the grass or dirt can compact the soil. The heavier the weight or more intense the activity, the greater the soil compaction.

"That stops water from soaking in (to the soil) and stops oxygen from getting into the soil. All those things can cause root death," Bell said.

Soil compaction only adds to the natural stress the trees experience in an urban environment, including additional heat that comes from being near pavement. The more stressed trees are, the more likely they are to be susceptible to insects or diseases. Often, if a tree has a bug infestation such as ambrosia beetles, or a fungal disease, by the time the issue is noticeable, the tree is beyond saving.

"It’s a very real concern of mine that the trees are damaged by all the activity out there, but we can mitigate most of that damage with regular care," she said.

One thing Bell would avoid doing is setting up stages, bleachers or grandstands on any part of the square, as it could harm not only the trees, but also the grass, which has a few bare spots that have developed over time. She’s hoping the fact the roads around the square are a state highway will allow the city to more easily close the roads for events, and place grandstands or other large fixtures on the street.

As for the general public, Bell said it’s better to bring a blanket to events such as concerts, as even the pressure from the four points of a chair can compact the soil. She also advised children, and adults, to avoid climbing on the trees, because their large branches could be susceptible over time to breaking.

Heavy equipment should never be allowed on the square, Bell said, unless absolutely necessary, as even a single pass by a piece of heavy equipment can compact the soil by 90 percent.

 Soil solutions

One key to keeping the trees healthy is to protect the soil.

Though it’s only been done twice in the past six years, Bell said the soil on the square should be aerated annually, and fertilizer and compost should be added on occasion.

She said a constant 2- to 3-inch layer of mulch should be kept on the soil around the trees at all times. The key to mulch is that it can disperse the weight on the soil more evenly and reduce compaction. Too much soil prevents water from getting to the roots, but a consistent 2-3 inch layer would offer protection and allow filtration, Bell said.

While the trees have occasionally been treated with pesticides, Bell said they really need a more regular seasonal treatment by a qualified company.

The county also has been regularly having the trees’ cabling inspected, and Bell said that needs to be kept up.

As for the grass on the square, Bell said the county considered replacing the current variety of grass ("Meyer" Zoysia) with a similar, but more traffic-tolerant variety (newer "Empire" Zoysia). As far as the grass goes, there is no 100 percent protection against the traffic, but the newer variety will stand up better. The county considered replacing the grass a couple of years ago, but the cost of $12,000 was too high at the time.

Other trees needed

The trees that line the outside of the square are sugar maples, and Bell said they’re not particularly well-suited to the South’s warm weather and are in pretty bad shape overall. She’s recommended replacing them with a variety of trees, including some Princeton American Elms, perhaps some oak trees and one more variety. Those trees would grow taller than the ones around the square now, which is a more similar look to how the square used to be decades ago when water oaks were popular.

However, the water oaks began to die and became unstable, causing some problems, including crushing a couple of police cars near the station when they fell.

She said the White Oak near the stage in the southeast corner is doing well, but also needs regular treatment. It was planted partially in the hope that it would grow tall and wide to give the square some presence even if the magnolia trees eventually died.

A tree could be put catty-corner to the White Oak – one used to be there – to allow the matching quadrants to trade off with impressive trees every few generations. However, officials may choose to keep the quadrant with the war memorial all grass to promote more activity there.

Replacing a magnolia

As a native to the Southeast, the magnolia tree is a good choice for a town square, Bell said, adding that she would probably just replace the current magnolias with others if they died. Though you can transplant larger trees, it’s riskier and more costly, Bell said. If you took a normal sapling, Bell said it would begin to have some presence within a decade or so. Of course, it will take a while to rival the visual impact of the current trees, which Bell estimates are close to 60 feet tall.

However, as long as the current trees are cared for, they should last for a while. Even when a tree begins to go into natural decline, it can live and look normal from the outside for years.

The city’s job

While Bell has done her best to care for the square on a limited budget, the responsibility now shifts to the city of Covington under the agreements the city and county recently signed.

The city, which already performed some maintenance, will now be responsible for handling all maintenance of the square. However, the county still has the final say in any permanent changes.

Given both parties’ vested interest in a successful downtown, for tourism, economic development and community identity, the groups will be eager to make sure the square remains healthy.

Commenting is not available.

Commenting not available.

Please wait ...