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Tree IQ tested

by Wyoming Livestock Roundup

By Tom Heald

It’s not lost on me Wyomingites are passionate about their trees. However, sometimes it is easy to get confused about how trees grow and live. Here is a little tree IQ test to get the cobwebs out of our brains.

True or false?  Trees have roots systems growing deep into the soil.

False. Trees have expansive roots. In fact, 90 percent or more of the roots of trees are found in the first 12 inches of the soil.  Researchers have shown the root system of most trees is at least five to seven times as expansive as the tree itself.

In other words, if someone were to cut down a mighty, 70-feet tall cottonwood tree, the roots can easily extend 350 feet or more from the base of the tree. Put another way, when we water our yards, we are most likely watering our neighbor’s trees and vice versa. This takes on a whole new meaning to being neighborly – or not. 

True or false? Trees heal their wounds and injuries much like humans.

False. Trees never heal themselves. In fact, they record every injury they ever sustain. Trees do not heal, instead, they seal off injury from the other living parts of the tree, this is called compartmentalization. 

All of those commercially available wound dressings do nothing to help the tree. It has its own defense strategy, and wound dressings can actually help decay organisms infect the tree by sealing them into the wound.

True or false? A branch that gets started when the tree is young will actually move up the tree as the tree grows up.

False.  The location of the branch never moves up the tree. It will remain in the same place until it gets damaged, broken or pruned.  Instead, it continues to grow outward and gets larger along with the tree proper.  

True or False? If one is to err on planting a tree too deep or too shallow, it’s best to plant too shallow.

True.  As stated in answer one, the roots of trees are shallow – the reason being is roots need oxygen and water, and those nutrients are highest near the surface. 

By planting shallow, one errs in favor of the tree and its roots. Planting too deep can actually kill trees because they are oxygen deprived.

Another reason is bark tissue of a tree is different than root tissue. Planting a tree too deep can actually cause the bark to begin rotting, therefore killing the tree. In my years as a county agent and now as garden center owner, I have consistently found people, including landscape professionals, planting too deep. 

True or false? Topping a tree is considered very bad for trees.

True.  Topping is indiscriminate pruning of trees and can hasten the death of a tree, or at the very least, create an ugly caricature of the tree.

Interestingly, topping got started in the middle ages in Europe. It was done to harvest wood for energy, while still leaving the tree to live.  It was a human necessity. GI’s in World War II saw a lot of topping being done in Europe for the same reasons it was done in the middle ages. They construed topping as a European method of arboriculture and brought the procedure back home.

Those who got all five questions right might want to consider being an arboriculturalist.  Those who missed all five may want to attend a tree workshop nearby.

Tom Heald is the owner of the Wyoming Plant Company Garden Center in Casper. For more information, contact Heald at or 307-262-2963.

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