Why do Amish guys have beards but no mustaches? Though this is based on a small amount of observation, I’ve noticed that the Amish men who have beards never seem to have mustaches; just the sort of ear-to-ear sideburn thing. Why is this? Is their lifestyle not conducive to the mustache, or is it more of a religious thing?
I’ve thought about this for years yet never heard it discussed.
The Amish have traditionally associated mustaches with the military and police, and do not wear them so as to symbolically separate themselves from those groups.
Cite (found by Googling “amish mustaches”)
This practice, along with many others, appears about to change.
I know that Mennonites and Amish are not synonymous. But I’ve heard from a Mennonite friend of the family that the reason Mennonite men don’t wear moustaches is that Mennonite women don’t like them. I would not be surprised to learn that the reason is the same for the Amish.
I hadn’t even noticed. Do some people think I’m Amish because I have a beard and no mustache?
I believe Scarlett67 is correct. Don’t have a cite, but that’s what I was taught in Sunday School … Practice died out quite a few years ago in my denomination (Church of the Brethren, a closely related Anabaptist sect to the Mennonites/Amish), so that may already have reached, um, ‘pastoral legend’ status. 
Didn’t stop my minister from teasing me when I came back from college with a beard & mustache. My parents were a bit flabbergasted, but suggested one day that I shave the beard & leave the mustache. The good reverend happened to be near at the time, and said I should go with the ‘traditional’ look instead & shave just the mustache. I’m pretty sure he was joking, but my folks didn’t seem to find it amusing …