You have met the challenge of rotted wood head-on, Ursula.
I try to be very careful to only use woods that are durable and rot-resistant. I think I have done a pretty good job picking and choosing. I absolutely know that the majority of my mounts will last a lifetime and with some, several life-times.
I just love working with woods, some common and some exotic. Heck, I cannot begin to tell you the woods that I have prepared and did not have a clue what the wood was. On occasion I have taken or sent photographs to wood "experts", asking what the wood was. The majority of the time, the expert can't tell me. Much of my woods come from the base/root areas of the tree, and those woods can be so hard that my planning them or drilling through them will produce smoke. Other woods have been under water or lying in swampy areas for decades, and everything that is going to rot has rotted. What's left simply won't rot. Lots of my cypress and heart pine falls into that category.