Both of my horses prefer to roll in sand rather than mud or dirt if given a choice. Sand does not stick to the coat-even if it is wet, it brushes right off. Any time of the year you have grass growing, if you can get the horses to roll in grass, they don’t get dirty, except for a little green, which is easier to clean than mud! If you have your own place, you can get a small load of sand to make a rolling area about 4 inches deep and big enough diameter for a nice roll. Put it in a low traffic area of your turnout and away from fences and low spots so it does not get mixed with mud. You can teach your horse to use the new spot for rolling when you first bring him out, as that is usually when they want to roll. Halter your horse and attach a lunge line to give you plenty of room to stand back while he rolls. I taught my horses to roll by standing in the sand or grass and “pawing” the ground with my foot like horses do before rolling. If your horse likes to roll in the sand, chances are he will return to that spot even if not haltered. If you board your horse, maybe the stable would be willing to add a sand rolling area for everyone to use. As an alternative, wood shavings could be used for a rolling spot.
When I want to keep my horses clean, I put a Kool Coat sheet, neck cover and fly mask on them for rolling because I can wash these more easily than a full size blanket. One of my horses is white and one is chestnut. Ironically, the chestnut is the one who likes to be clean, but when she was a baby I had to teach her to sleep in her stall in the shavings as she had been sleeping in a pasture. I showed her I could lay down in the stall-I stretched out and told her how soft and dry it is…the next morning she had shavings all over her instead of mud from sleeping in the paddock! She also started to paw the pile of shavings out of the corner at bedtime! I think she is a smarty!