untuck
If you are able, no dress code, outside, summer, etc....why not just untuck, and consider an IWB holster as well. That is not comfortable w/ some folks I admit.
But, an "arborist" outside, lawns, parks, etc...... Who cares if your shirts not tucked. Some attention to holster and how you carry and handle yourself, and I'd think you'd be fine. I manage 4-5" barreled autos in OWB holsters like the Glock sport and untucked "fishing shirts/river shirts" and khaki's until it gets REALLY hot here, then resort to pocket carry with a smaller gun when it is just stinkin' hot. I also do a sleeveless tee and an open river shirt too, but that is a bit sloppy for business casual. Would a mild colored Hawaiian work now and again too?
Before I got fat as a pig, I managed a Colt Commander IWB for years in a "Summer Special" sort of IWB. river shirts and Hawaiian's.