There’s an old joke: What’s worse than finding a worm in your apple? Finding half a worm. For an apple-tree-owner, worse still is finding a worm – or worm holes – in every single fruit on your tree.

Q: I have had wormy apples in my Honeycrisp apple tree. Last year, I had the same problem. I was told to spray a fungicide. I also sprayed neem oil. I waited until the apples started to form. I still ...