I take both mine to the Groomer 3X year.
Given my location (HotSpot USA/Houston TX) they get very close trims in February and June. Then the October trim, which is more of en even the hair up (but a little longer) for the winter months. On the June trim, I have their chests and belles scalped, they SO love to plop down in a puddle of water to cool off, or just jump into the Bayou for a quickie.
Given how active my guys are, in that we go jogging/hunting down along the Bayou, having them with long hair would be a disaster. It's still trouble enough, given that I allow the hair on their Ears and Tails to grow long.