Q. I had a lot of borer damage to my trees so last summer
I cut out most of the large branches and reduced the height of the trees to
about 10 feet and let them grow back. Then I treated the soil with an
insecticide, surfactant and fertilizer. That was my counterattack regarding the
borers.
I cut out most of the large branches and reduced the height of the trees to
about 10 feet and let them grow back. Then I treated the soil with an
insecticide, surfactant and fertilizer. That was my counterattack regarding the
borers.
 |
| Borer exit holes in the trunk of Italian Cypress sent in by an alert reader. |
A. Make sure trees that you do cut back will grow back.
Some trees like most ash trees will not grow back very well if they are pruned
severely. Also make sure the pruning instruments are all sanitized before
pruning.
Some trees like most ash trees will not grow back very well if they are pruned
severely. Also make sure the pruning instruments are all sanitized before
pruning.
 |
| This formulation of imidacloprid (this name is found under ingredients) is probably the most common one found on shelves. Shop around because there may be some that are less expensive. Compare the percentage of imidacloprid on the label with the price of products. Higher percentages single just means you get more “bang for the buck”. |
Insecticides
like Imidacloprid (active ingredient) used as a soil drench (mixed with water
and contained on the surface of the soil above the roots) are systemic and
taken up by roots of the tree and kill many types of borers. Whatever
insecticide you use should be systemic and have a label that says it is
effective against wood boring insects.
like Imidacloprid (active ingredient) used as a soil drench (mixed with water
and contained on the surface of the soil above the roots) are systemic and
taken up by roots of the tree and kill many types of borers. Whatever
insecticide you use should be systemic and have a label that says it is
effective against wood boring insects.
 |
| Excerpt from the product label of Imidacloprid 2F manufactured by Prime Source LLC. The active ingredient is available from several manufacturers so it is imperative to read the product label before making any applications. |
If the insecticide
has “staying power” inside the tree then I would apply it after the tree
flowers. This is usually in early spring. Long-lasting, systemic insecticides
like Imidacloprid are suspected to harm honeybees. There is a possibility the
insecticide could be available to honeybees if it is applied just before
flowering.
has “staying power” inside the tree then I would apply it after the tree
flowers. This is usually in early spring. Long-lasting, systemic insecticides
like Imidacloprid are suspected to harm honeybees. There is a possibility the
insecticide could be available to honeybees if it is applied just before
flowering.
 |
| A portion of the product label for Imidacloprid 2F warning about killing honeybees. Be careful when you spray insecticides or apply them as a drench to the soil. |
I
am not sure why you are using a surfactant unless it is to help this
insecticide drench move into the soil faster after drenching the area.
Surfactants are a very broad category of spray additives but usually used to move liquid
fertilizers, insecticides and fungicides inside plant leaves when they are
sprayed.
 |
| One example of a surfactant. When mixed with a spray it helps the product get inside leaves or stems. When mixed with a liquid drench it might help the drench move into the soil better. |