This website is an ongoing effort to provide an educational source no charge. Understanding how to care for trees, and how to properly prune could be taught to grade schoolers. It is sad that we treat some of the oldest and largest living beings on our planet in such an ignorant manner. Understanding and caring for ourselves, and how to care for a pet are other educational deficiencies that allow many problems to remain endemic in our culture. Arboriculture has had a tremendous inflow of scientific information in the past 20 years, but there are still many misnomers in circulation.
- Trees have taproots. In grade school in the 50's we studied pictures of trees that had a taproot almost as deep as the tree is tall. The fact is that tree roots need oxygen to elongate, and oxygen levels decrease with depth, especially in clay soils. So tree roots can only exist in the upper layers of soil. Uprooted trees exhibit the convoluted sandwich of roots that the tree sat on. No taproot. Trees are held up by an extensive lateral spread of roots, and uproot when rain saturated soil becomes too soupy for them to hold on to in high winds. Most trees roots are in the top 8" of soil if it is clay soil like Middle TN.
- Tree wounds should be painted. Tree paint does hold out bacteria, but the greater threat is from fungi, which like it dark and damp - the environment provided by an opaque layer of tarry paint.
- Trees should be pruned at transplanting. This was based on the idea that a tree looses 80-95% of its root mass when it is dug at the nursery, and this reduced root mass should have fewer leaves to keep supplied with nutrients and moisture. True, but what is true and more relevant is that the hormones needed for root growth are produced in the branch tips. Newly installed trees should not be pruned until they have become "established" and regenerated the lost root mass, which takes 18 mos. or so in Mid TN.
- If a tree is alive and has not been obviously wounded, construction activities have not hurt it. The damage done to tree roots by construction and other traffic may not be obvious to the untrained eye until the tree has severe dieback. Decline and death from this type of damage normally takes 3-5 years, and can go on for 10 years. Twig elongation (internodal growth), and tip dieback are good things to look for in determining the degree of decline in a tree.