Insects and Diseases Attack
Every Tree and Shrub
Every Tree and Shrub
Our Native American species survived for millions of years with the ravages of our native insects and diseases. More recent events show an acceleration of different infestations that cause catastrophic damage. This section is for the controllable ones.
If you have ever planted a garden, you know how pests, insects and diseases attack the plants. The same happens with the trees and shrubs. Each specie has its own predators.
You should not purchase any specie undergoing catastrophic damage (endangered):
- American Chestnut (Castanea dentata)
- American Elm (Ulmus americana)
- American Sycamore (Platanus occidentalis)
- Eastern Hemlock (Tsuga canadensis)
This list changes constantly and these four trees are only an example of common knowledge for Urban Foresters. You should research what type of tree or shrub you want to plant and follow a criteria for your choice. The best way to have current information and advice is to contact your local County Extension Agent.
Pennsylvania is a land grant state, initiated by Abraham Lincoln, to grant States federal government land in exchange for establishing a College of Agriculture and placing an extension of the College in each County. These satellite County offices would forward new information to farmers and send back questions for the College to research for an answer.
Protect Against Insects and Diseases
This link will show a chart for the different problems with each specie of tree and shrub. Is this too much research? Just tell you which specie has least number/severe problems? First, you need to decide some basic characteristics for the trees/shrubs you want:
- What is the maximum height/size you want?
- How close to the house or another structure will it grow?
- Is color (spring flowers or fall bright foliage) important?
- How much shade do you want?
- Do you want fruit?
- What rate of growth is best?
Once you decide this basic information, you then will see the choices available. Now contact your extension agent and list the specie you want to plant and ask for information about their care, maintenance and vulnerability to infestations. Certified Nurserymen are qualified to answer these questions – I prefer to first contact the County Extension Service then contact the Nursery.
Your Awareness
Every Native American tree listed above had an outside source for the invasive insects and diseases that caused catastrophic damage. For example, American Chestnut (Castanea dentata) in the early 1900's started to die after the pathogenic fungus Cryphonectria parasitica, native to East Asia and South East Asia, and was introduced in the early 1900s.
This specie was used universally in the U.S. for the its beautiful wood for furniture, structural members in building, delicious fruit (remember the lyrics "chestnuts roasting on an open fire"), resistance to insects and one of the most prolific trees growing in the United States. When the Chestnut Blight struck down ALL these trees - the nation's streets and private property were now exposed to more sunlight and every tree had to be removed. Not all four billion that succumbed to the blight - only the ones that would cause humans injury when they deteriorated enough.
How to Detect a Problem
Tree situational awareness:
· Do you hear a Woodpecker? They make holes in a tree that insects and disease love to find and infiltrate the tree.
· Do you see carpenter ants? They bore holes in trees which wound the tree and provide an entry point for insects and disease.
· Do you notice sawdust at a tree? Look closer and find the source.
· Is that weird looking thing growing on the tree going to be a problem?
· Did lightning strike the tree and leave a scar? How will you treat the damage?
· And many other questions.
· You may need to take pictures of anything you find suspicious and sent them to the extension agent with your questions.
This information may take a while for the County Extension Agent to receive, research and reply to you. You will have to make more decisions after you receive the reply. This time consuming process is a lot less costly than contacting a third party as a tree surgeon. In addition, the extension agent will have the most current information as opposed to a nurseryman or tree surgeon.
