MythBuster: Trees Edition
Myth Definition: A belief not based on science or facts, including misconceptions and misunderstandings.
Myth - You must amend clay soil with peat moss or compost
In most cases, backfill with the same soil that you have removed from the hole. Amending the clay soil could create a condition like planting in a pot without drain holes. Root rot may occur as a result.
Myth - Plant trees deeply so they are more stable
Planting depth should be the distance from the tree’s root flare to the bottom of the root ball. You might have to carefully remove some soil at the top of the root ball to expose the root flare. Too deep and you encourage poor root development and decay.
Myth - Pile up mulch around the tree trunk for protection
Mulch piled up around a tree’s trunk can lead to stem girdling roots (a strangling effect cutting off sap flow) and decay at the base of the tree. Mulch should be maintained at 3-4 inches deep and pushed back a few inches at the base of the tree.
Myth - Wrap the tree trunk to prevent heat and cold injury
Wrapping the trunk of a newly planted tree is usually unwarranted. Smooth tree bark contains chlorophyll and can photosynthesize tree sugars for energy. Tree wrap may be warranted in late fall and winter to prevent damaging deer rubs and winter sun scald.
Myth - You cannot over water a newly planted tree
It is very important to provide supplemental water during a newly planted trees establishment period. Usually a full growing season. Too much water can suffocate newly forming roots and can harm a tree quicker than a brief dry spell, which stimulates root growth.
Myth - Fertilizer is tree food
Sugars produced during photosynthesis are tree food. Fertilizer provides 17 essential mineral elements for all life processes.
Myth - Fertilize root damaged trees
Fertilizing root damaged trees can promote root decay and stimulate greater crown growth. A damaged root system is unable to adequately supply an existing crown with water and mineral elements. Stimulating greater crown growth at the expense of the root system only compounds problems for the tree.
Myth - Prune branches flush with the trunk
Pruning branches flush with the trunk, behind the branch bark ridge (area of raised bark at the branch attachment), or branch collar (a swollen area at the base of the branch) creates a larger wound into the trunk, leading to decay. Leaving branch stubs can be equally undesirable and lead to trunk decay.
Myth - Do not prune trees that bleed in the spring
Bleeding is a defense mechanism. Little harm results from bleeding sap.
Myth - Tree wound paint prevents decay
There is no scientific data to support this.
Myth - Tree wounds heal
Trees cannot restore injured tissue like humans. Tree wounds are compartmentalized within the tree. It is a natural defense used to resist the spread of decay.
Myth - The size of a tree pruning wound does not matter as long as a proper cut is made
Tree pruning wounds less than 4” in diameter will generally close preventing decay. The larger the wound, even if made properly, may not close, leading to decay. Very large wounds may never close.
Myth - Topping rejuvenates and invigorates trees
Topping causes a tree to use up vital energy reserves and promotes the production of fast growing, weakly attached branches. Topping leads to tree decline.
Myth - Ants cause tree decay
Carpenter ants do not eat trees and cause decay. The ants create galleries within already decayed wood for reproduction purposes. The galleries are kept very clean and can slow the decay process.
Myth - Removing conks and mushrooms stop decay
False: conks and mushrooms are reproductive structures only. Removing them does nothing to stop decay.