Q: I lost all 12 of my Leyland cypress trees to seiridium canker. I was told by an arborist that the disease spread via the ground, and that there wasn’t anything I could have done to prevent it in the first place. He explained that once they were infected, there was nothing I could have done to save them. Some of the trees were higher than my two-story house, and I am still very upset over my loss. Over the years (the trees were about 15 years old when I had them removed), I pruned the trees with hand pruners and a lopper. I never knew about sanitizing tools to prevent infection. I certainly do now! Do you think my lack of tool sanitation is what caused my trees to become infected? A: This is such a sad tale of loss that might have been preventable. At the same time, …