My poor Fan-Tex Ash tree. It is sapping all over, and it can only mean one thing– borers. Ash trees can be susceptible to these insects. By keeping the tree well watered and fed, you should be able to keep bugs at bay.
Unfortunately, my irrigation system has been watering too close to the trunk and not at the edge of the canopy, the drip line. If you think of a tree’s canopy as an umbrella, the drip line is the outside boundary where the water would run off. The majority of water gathering roots are located under the drip line.
I have plans to change this and redistribute the water, but obviously did not get to it soon enough. I could tell the tree got quite stressed during the hot summer.
Now, I’ve got to kill the borers before they kill my tree. Like it or not, I have to use a systemic insecticide. A systemic penetrates all parts of the plant with poison. Since borers reside and feed inside the tree, there is no other way to kill them. Contact killers cannot physically hit the borer and therefore are useless against them. I use organic pesticides whenever possible. It pains me to use this poison, but it’s a necessary evil if I want to keep my 8 year old tree.
With borers, a year-long systemic is the most effective. I will use Monterey’s Once a Year Insect Control. This is the second time in the tree’s life I’ve had to treat it. Hopefully, with redistributing the water, it will be the last time I have to use this poison.
By Cara Bohardt, Desert Gardener
What is your experience with borers?