My dad pointed at to me that I probably shouldn't be wearing my gun when i'm working with stuff like the grinder and such. I generally apply the same reasoning to carrying while landscaping. For reasons of practicality, it might not be good to be OCing while using a weed whacker, but it may not be such a big deal on a lawn mower. It might be simpler to just have a pocket pistol.
As far as the customers concerns, i completely understand. I work with/for my dad doing audio/video/lighting installs. And his business tries to mostly cater to churches and the like. So, I constantly wonder the same thing. That being said I have only OCed in one church to date. The pastor seemed pretty cool about it. As did his son, who also found it important to try to announce it whoever was nearby. He thought it was funny. I didn't so much.
I think that I've rambled enough to get my point across somewhat. But yeah, I completely understand the concerns. My dad doesn't mind, but it's the customers that can be hit and miss and are not always easy to judge.