I do on occasion...I don't lunge as a rule but will have to start as a way of getting one of my pony's to drop some weight and help her clicky stifles.
As an oldie, I must state we, lunged, long reined, schooled and did everything on grass for years, just make sure its not too bumpy, muddy, hard or slippy.
Only have access to grass, so yes lunge on grass, also do flatwork, jump etc on grass. Obviously all depending on the state of the ground, but having started riding when I don't think anyone had schools with surfaces I have never considered it a problem, apart from the fact that it doesn't do the field a lot of good.
Also schooled in the depths of winter on a sloping field and, when I was younger, had far too many horses to ride and time was at a premium, I have been known to school in walk and trot by the light of the moon. (Not any more I hasten to add
I lunge on a grassy slope as don't have a school at present.
I keep the circle massive (11m lunge line, plus I walk a circle in the middle and move around the field a fair bit) avoid very hard ground, don't do too much canter, and stick to 20 mins as an absolute maximum. No problems so far, and certainly no problems with slipping/tripping
All of my lungeing is done on grass, as I don't have an arena.
Personally I think a well maintained grass school is potentially better on the legs of a horse than a poor school surface (and let's face it many are poorly maintained, deep etc).
There is no movement under the horse, only the "give" in the going, which makes for very stable footing.
Of course, I would say that as I don't have a manege. Maybe I'm just kidding myself into thinking I'm not being hard done by!
I work in walk, trot and canter on the lunge. Obviously I wouldn't canter on an overly hard surface in the grass school or a very wet one.
I have lunged and schooled on grass when i didn't have access to a school although i havent done it for many years, I can say i have had less horses loosing footing on grass than in the school when hooling about.
Yes, well used to before I moved onto a livery yard when had our own fields, had no choice, providing your sensible about it, take into consideration the individual horse, they way it goes on the lunge, ground conditions and size of your circle and the speed your asking etc then it's no different from riding on the grass, or if your horse is looning around when there loose in the field.
Only advantage I have found is that your in an closed off safer area when your lunging in school and your not as effected by the good old British weather so much.
When my horse comes back in to work, I will eventually start working her on grass, and lungeing to start with. I have access to a great indoor school and we will have an outdoor one as well. But the reason for me wanting to work on grass is that on the occasions that we competed on grass, my girl just couldn't cope with the change of footing very well. So rather than starting by riding on it when we potentially could fall over, I'd rather her learn to find her feet by lungeing first and then move on to ridden work. However, that's a long way off at the moment as we're going to be restricted to the school for a bit as my mare is recovering from a bout of lami.
I never used to lunge but have started no im getting kreeky! While its slippy I use the yard with fine gravel better than slipping on the side of the hill and They can not get away from me We have to lunge on grass at shows so I can see no problem just keep them balanced and steady AND booted!!!
If you go to any of the big events, even the likes of Badminton and Burghley you will see top horses being lunged on grass. If you are careful and know your horse well why not?
I used to lunge my old cob a lot on grass and would seek out areas of the field which had little inclines or changes of terrain. It was invaluable for encouraging him to balance himself over undulating ground plus the hilly bits helped with muscle tone.
and don't have a school so do it in the field but find that I have to keep him in trot/canter as he tries to eat the grass at walk
The only time he has lost his balance and actually fell over was when he was being a total a*se and pratting about cantering - and that was on a perfect surface in a school