Our weeping Alaskan cedar has borer. The exit holes are D-shaped which apparently is caused by flat headed wood borers. My question is how can we restore the tree back to good health? We were told that spays of some kind (don't know what that may be) applied at the right time in the spring can help but I would like to hear from an experienced gardener on a fix.
Control of Borers on Weepng Alaskan Cedar
Certified GKH Gardening Expert
Yes, neem oil, or any kind of peppers boiled into a spray will work well. This collection of articles will give you more information on making your own pest control, and many other things: https://www.gardeningknowhow.com/special/organic/