Shade Tree Decline

Thatch | Shade | Shade Tree Decline | Weeds | Soil Compaction | Surface Insects | Grubs

WHAT IS IT?

It's a term used to describe a tree in deteriorating health due to a variety of factors. Symptoms are usually subtle and slow developing. Premature fall color change, smaller and fewer leaves, and early leaf drop are early symptoms. Later branches may die out at the top of the tree and browning of the edge of the leaves may occur.

WHAT CAUSES SHADE TREE DECLINE?

Many times a combination of factors causes the problem. Some of these are:

• Late spring frosts
  
• Summer droughts
  
• Salt injury from winter use of salt
  
• Cutting the roots when trenches or foundations are dug.
  
• Wounding the trunk with the mower, string trimmer, or other equipment.
  
• Extra soil added or taken away under the tree canopy.
  
• Mulch that is too thick
  
• Soil compaction
  
• Natural gas leaks into the soil
  
• Excess soil mositure
  
• Repeated defoliation such as from insect damage or hail
  
• Lack of nutrients
  
• Girdling roots

HOW CAN DECLINE BE CONTROLLED OR PREVENTED?

Good site selection for the specific variety of tree or shrub is important. After that trees need to be fertilized in the late fall (after the leaves have fallen) or in the spring. They need to be watered during droughts and protected from wounds to the bark. If decline has begun, thin out the top by selective pruning. Aerate the soil if it has been compacted. Do not permit any heavy equipment to drive over the root zone of the tree.

We tend to look at trees as hardy, durable plants but they are very sensitive to many stresses. They may not die quickly but they will die if subjected to a variety of stresses.