Q. Every couple of years or so I get attacked by moles. None of the surrounding yards get any but they love my place. They have stayed away the past two to three years but they are returning with a vengeance. In the past I have tried various things to rid my yard of them. Poisons, traps, etc…I never know if one works or not, and they stay for a very long time anyway. Please give me some practical advice on how to make them go away. My yard has many fir trees in it, and lots of shade, which brings me to my next concern. The past two years I have notice round holes and falling bark from three of my fir trees in the back yard…. In the 35 years I have lived here, I have wrestled with carpenter and moisture ants. well, all kinds of ants!! I spray the trees two to three times a year and even had them professionally treated and sprayed for four years. Also the house. I am worried about the health of the trees now and have had some Tree Guys out to estimate limb removal and thinning and was told that they are healthy other than for some beetles that are in side the tree and that woodpeckers are eating the bugs and making the holes. That was not exactly comforting to me. I worry that the inside of the trees are being eaten away and will weaken and fall. Also it is curious to me why they just appeared two years ago. Other than having the trees taken down, can you advise me what to do. Margi Fishbaugh – Lakewood, WA
A. The moles “attack” your yard because it is providing them with a food source. They are predominantly insectivores feeding on beetles, grubs, and other insect larvae as well as earthworms. The moles will either leave when the food supply is exhausted or if there is something in the environment that suitably discourages them from feeding there. Eventually they come back again when the food source builds up again or the nuisance is gone. This is the reason for the cyclical nature of your mole problem. I am sorry to say that total control is very difficult. There are many ways to control individuals including repelling, poisoning and trapping but if you don’t get rid of the whole local population then the issue can reoccur as you have seen. A good explanation of our local moles is available from the county extension:
http://cru.cahe.wsu.edu/CEPublications/eb1028/eb1028.html
I generally recommend controlling grubs and other insect larvae (if you find they are present) in the soil using organic methods and therefore reduce their food source and therefore the damage. Again this does not guarantee complete control. As far as your trees are concerned if you did your homework in selecting your “Tree Guys” and they are certified professionals then their advice would be sound. If they say your trees are healthy and not hazards then I would trust them. If you are not sure if they are certified ask if they have ISA (International Society of Arborists) certification. Or you can check yourself (or select one) by using The ISA’s website search function:
http://www.isa-arbor.com/findArborist/findarborist.aspx
The fact that woodpeckers are feeding on the beetles means they are also keeping the tree pest free and healthy. They are much more persistent than you could ever be in a spraying program.