Hello! I have a 5-year-old State Fair apple seriously infected with fire blight. Trunk has become bare at the root stock join. Interestingly, the tree did flower quite well. Now, the leaves are very small. I want to remove the tree but not infect the surrounding trees -- especially a Mountain Ash about 12 feet away. Also, I'd like to replace it with something resistant. Is the soil likely infected, and can the soil infect a new tree? Will any remaining pieces of root infect what I put in it's place? I'm in zone 4b. Any suggestions of what to put in? Thanks!