After about 1.5-2" of growth (total length) longer hair doesn't matter, except as many of you say, it is more trouble to groom, and without that, looks messy.
I groom my guys about three times a year, with the March and July sessions, clipping them down to a #7 (about 3/8ths inch), because of our extremely hot weather down here. I run my guys twice a day in a straight Jog for a half mile or so, or, allow them to hunt along the Bayou, where they jump in to catch Frogs and Snakes. They're a LOT easier to rinse and dry with short coats.
The September/October Grooming, is just a light trim, with the intent of lengthening their coats for the expected cooler weather, and, jumps in the Bayou past October are discouraged.
We usually do a circular Run, but, given our new member "Ickey", I've rerouted to do a figure 8, dropping him back at the house, while the adults continuing on for their usual distance. He should be in shape by the time he's a year or more, to run the whole distance.
Meet Ichabod !
http://www.yorkietalk.com/forums/4044881-post1.html 