mcseccnp

I have always just use lime sulpur. You have to apply once a year never have much of a problem of rot. Sounds like you are water a little too much. Make sure you dont carve into the soil line. If you put varnish on it it is almost forever before it will come off. I have never seen a varnished tree. I have a lot of carved trees lime sul has always worked for me. Just another opinion. You know what they say about opinions.