Our plant pathology professor at Penn State, Les Nichols, didn't always teach us what we expected. We were in his class to learn about tree diseases and fungus, or so we thought.
But he was experienced enough to spend half his time teaching us about the things we might someday mistake for plant diseases that were actually caused by more common things.... problems created by storms, unusual weather or physiological types of problems having to do with a tree's roots.
Professor Nichols always said that if we saw trouble in the top of a tree to check the roots first. Forty years of landscaping experience has proven his words to be right on the mark, "golden" in fact.
There are many things beneath the soil, out of sight, which can kill ornamental shade trees. So let's take a look at some common (physical) causes of tree mortality.
Larger trees have always been moved by digging a root ball that is in proportion to the size of the tree trunk. Root balls are typically 10 to 12 inches in diameter for each inch of trunk diameter. Trees handled this way are called "B&B" which stands for "balled and burlapped."
Back in the old days, natural burlap was used for wrapping wrap root balls to contain the soil, and twine was used to cinch them up. This tying of root balls with twine was called "drum lacing" since the roping pattern resembled the sides of a snare drum.
The problem with using these natural burlap and twine products came when nurseries would have to hold trees for more than a couple months. Burlap and twine typically began to rot away, increasing the likelihood of the earth ball falling apart when the tree was moved to its new home. Someone came up with the idea of treating burlap and twine with chemicals to extend the hold time before they began to rot. Treated burlap and twine is typically green in color, instead of a natural tan color. These products are still in use today.
At some point, a few other "new inventions" came down the pike. One was the wire tree basket, which is a woven metal basket that a root ball is lowered into after the tree is dug. Tree baskets save time by eliminating the labor involved in drum lacing. A new burlap called "leno" was produced that used plastic fibers, greatly lengthening the hold time of B&B trees in a nursery. Natural twine was replaced with plastic twine to also increase nursery hold time.
While B&B trees are held at a nursery, they begin to root-out through the synthetic burlap. The longer they are held, the more difficult it becomes to remove this synthetic burlap material due to extensive root growth. At some point it becomes nearly impossible to remove, and the best that can be done is to cut away as much of the material as possible without killing the tree in the process.
Unfortunately, some unscrupulous nurserymen, in an effort to save time and increase profits, have planted trees without any concern for their longevity. Synthetic burlap and plastic twine has been left tightly wrapped around the root ball and trunk, basically signing the tree's death warrant when it is planted. While a tree may penetrate the synthetic burlap with small roots, the tree isn't able to root into the soil like it should. Furthermore, tightly bound tree trunks become 'girdled' by constriction, especially from synthetic twine (and sometimes by guy wires).
The resulting tree problems may take a decade or three to show up, but they will surely come. We saw a 30-foot White Pine get blown over by high winds since it wasn't properly anchored with a good root system, due to synthetic burlap. Other trees, like the one of the choked rootball below, begin to struggle and exhibit problems that could be easily mistaken for disease or nutritional deficiencies.
If you have a tree exhibiting problems in the top of the tree check the roots first!