Girdling tree roots

Girdles and girdling. When I heard these words on Saturday, I had flashbacks to long lost lady’s lingerie, so imagine my surprise when I realized we were talking about trees, not fashion undergarments.

Girdling was a new term for me, and learning about girdling roots came with a sad story.

One of my favorite trees growing in the WVU Demonstration Garden at the State Fair is sick. It has girdling roots and is dying.

In this garden, there are two Japanese Maple Trees that have been a part of the garden for 15-plus years. This summer, the volunteers noticed that one had vibrant reddish leaves and one had dull green leaves. It was time to call a tree expert.

A tree doc will perform a thorough exam, including shallow digging at the tree’s base. He will also look for classic symptoms – including the leaf color, the lack of root spread that may leave one side flat, and weak or breaking branches.

A lady’s or a man’s girdle wraps around the body and squeezes the body tight. This is exactly what happens when tree roots girdle. The tree’s own roots grow to wrap around the trunk and other roots. As this happens, it squeezes the tree and, if not treated very early, will squeeze the tree to death.  

As the girdling roots grow, they slowly cut off the supply of nutrients produced through photosynthesis and those absorbed through the ground from flowing freely through the tree’s system. To be blunt, the tree strangles itself.

Maple trees are susceptible to girdling roots. This can also happen to trees and shrubs grown in a container if they become pot-bound.

The most common cause of girdling roots is improper planting. Because we are approaching fall, and many of us will be adding shrubs to our gardens, here is a reminder. Preparation of the site is essential. It’s not about how deep you dig the planting hole; it’s how wide. The plant roots need room to spread.  

Each tree or shrub will come with planting instructions and guidelines. A good rule is to prepare the site 2 to 3 times the width of the root ball or as they say, dig a $50 hole for a $5 shrub.  I know that sounds like a lot of extra work and extra space. Trust me, it is worth it.  

Most trees do not want a deep hole. You want the root crown above ground. The tree needs oxygen. 

So please, please, don’t cover the roots and trunk with mulch. This is often called a mulch volcano. It is not healthy for the tree.  If you want to add mulch under your tree, pull it away from the base. This will give the roots space to “breathe”

After your site is prepared, remove the shrub from the container and spread the roots. This is not the time to be timid and gentle. It may mean getting a garden knife to break apart the tight roots. I generally slice off the bottom and make cuts in the sides. Then take my hands and pull apart the roots. What I am doing is giving them a chance to spread horizontally and not wrap around themselves.

If your tree has girdling roots and they are diagnosed early, you may be able to save the tree. There are several ways to prune and make incisions in the wrapped root to ease its grip. If you’re doing this yourself, study and do the research to learn proper techniques.

Once the wrapped roots are two inches or larger in diameter, things get tricky, and you should talk with a tree doc. You will need expert advice on the next steps to take for your tree’s health.

In the case of the Fair Garden’s Japanese Maple, the girdling root is almost 4 inches wide. It was diagnosed too late to save the tree. After the Fair and after thousands of people have had one last look, the tree will be removed. Plans are in place for a replacement – not a maple but a dogwood.

 I look forward to watching it grow and add a new beauty to this special garden.