If it is going to sit for a while park it on pavement/parking area of some sort. It is just a mess when you park one out in some mowed/grassy place and then finally move it plus the grass can grow up into the moving parts. The RV people cover their tires for UV protection, that might be an idea too.
On gravel so that it isn't sitting in any puddles or concrete/ pavement- definitely NOT dirt or grass!!! The tires dry rotted on my trailer from being parked on dirt (sometimes mud depending on the weather) and I blew two on the interstate (they looked perfectly fine!). After buying 4 brand new tires, we parked it on the driveway until we got a gravel pad put in for it. I was very lucky- it could have been disastrous.
Depending on your area, either a paved/concrete pad or gravel. We live way out in the country with a looooonnngg gravel drive anyhow, so whenever we get a new truckload of gravel we have part of it dumped on our trailer parking site, and a bit more dumped where we usually turn around. That way we drive the trailer up our drive, make a wide swinging turn in the grass to the point where we unload, then after cleanup we back the trailer straight onto its parking pad.
And because it's so handy to the barn and pastures, the trailer doubles as our tack room except in the winter (but that's another thread.......).
We had the driveway guys put in a pad of crushed concrete when they were doing the excavation for the driveway. It is just large enough for the trailer to sit on it, plus our little tent-style outbuilding. This year we added a bit more gravel to the front of the pad (where the truck sits) so hooking and unhooking in the mud isn't so messy.
I love having the trailer where it is--about 30 feet from the barn--because it's so easy to load and unload. Plus I can tie a horse to the trailer and give them a bath there, too.
We blew out a not-so-old trailer tire in early 2008, and another early this fall. When my hubby went to have all our tires replaced after the second blow out, the guy at the tire place asked him what we parked on and was told that we park on a gravel driveway, in an area where there are no water issues. He told my hubby that parking on gravel is not really enough -- that we should park on hard top (cement, pavement) or if not, he suggested plywood. Apparently moisture will still come up and impact your tires through the gravel. That was news to us! So we plan to (ugh, this is a reminder!) buy a sheet of plywood and cut it into four parts for parking.
"Our greatest glory is not in never falling, but in rising every time we fall." - Confucious
"dry rot" in rubber is caused by age and sunlight. Not by parking on grass. Parking anywhere for a long period of time can cause the tires to develop flat spots, especially if they are not inflated properly. This is also bad for the rubber.
We have no concrete at our farm so the trailer is parked in the hardpack gravel/dirt driveway in the summer when I use it all the time, and on grass when I put it away for the winter.
I check my tires every spring for wear and rot and proper inflation (and check the spare too). If you want to protect your tires keep them inflated and out of the sun. Sunlight causes a lot of damage - which is why it's recommended that your spare be kept covered.
Age is as big a culprit in tire life as use - so even if you don't use your trailer very much the tires can wear out and fail.
I thought about getting a tarp to cover my trailer but was told not to - the tarp will move in the wind and rub the paint off the top edges, and also trap moisture. So a garage would be ideal, but outside and uncovered is better than tarped. I suppose if you shrink-wrapped it like they do boats that might be better, but that can also trap moisture which leads to mold.
Not that I disagree with you Hilary, but FWIW, our trailer is in the shade most all day (a narrow fit between a tree and a pine tree) and I trailer 3+ days a week. The tire guys told us that parking on grass = dry rot and to avoid it at all costs. Just FWIW
so far as what surface is best for the tires... I have a feeling that the answer lies in what kind of drainage there is and how dry the ground.
Here in Michigan, where the ground is wet for all but about 2 months out of the year, I have to believe that a well-drained surface would be better than grass or concrete (where the rain/snow/ice can puddle). One year I parked on grass and the tires became frozen to the ground. After that I had crushed limestone drive put in. Once it's packed, it is super hard, but provides great drainage.
I bet in the SW, where the ground is dry and hard, parking on grass would be a poor surface and would suck moisture from the rubber (???) and lead to dry-rot.
I'll have to find an article that was published about 1 year ago in Western Horseman, I think, that discussed where / how to park trailer.
Definitely under cover is your best bet. I'm lucky to be able to park my trailer(s) in the giant shop DH built. My little 2 horse sits on a gravel pad with the jack on a piece of RR tie and the 4 horse is parked on concrete inside the shop proper again with a piece of RR tie under the jack. I swear my 1992 trailer hasn't aged a day since I bought it 5 years ago.
Yogurt - If you're so cultured, how come I never see you at the opera? Steven Colbert
When my tires froze to the ground years ago, I began parking on wooden boards. Tough to align, though. Now I park on top of pieces of rubber stall mats. They don't move like the boards did. Hope this idea helps.