We need to hang a hose hanger-thingy. You know, it’s a semi-circular thingy to keep the hose organized for neat storage. But, to hang this thing, I’d have to nail into vinyl siding. Is it ok to do this? What have others done to solve this problem, besides throwing caution to the wind, that is… 
I see no harm in nailing through vinyl siding. Just make sure you know what’s on the other side.
I have seen freestanding hose hangers. If you don’t want to nail through the siding, you could also make your own if you are mechanically inclined.
Vinyl expands and contracts due to heating and cooling. There will be buckling near the nails. Note that the siding is nailed on thru slotted holes. You could make your own wide holes but they would likely be visible.
Also, if you nail near a flaired part of sheet, you could crush it.
That’s why things which need to be firmly affixed to the dwelling such as exterior lights, receptacles and such are mounted first, or sit on mount blocks, and the siding is run up to them, behind a flange or channel accessory.
You might try using drywall screws. (with an electric screwdriver)
They’re self tapping and it seems to me they would make a cleaner penetration.
Do you own or are you renting?
Attatch the hose hanger to a wooden stake or post and drive it into the ground. Or, get a metal stake hose holder and drive that into the ground.
That way you avoid crimping up the siding. Besides, if you do try to screw through the siding, how would you know you got a good enough anchor? Often, vinyl or aluminum siding is used to cover over older weakened exterior treatments which might not hold up the weight of a partially filled hose of water held on by screws. Also, siding often has empty space and/or insulating foam panels behind it.
Play it safe. Don’t screw or pound nails through the sidiing.
You’re going to have to align your hanger with the underlying studs to have any support strength. Do you have the tools & know-how to find those studs behind the vinyl and the who-knows-what behind it?
Once you do locate a stud, you probably don’t want to use nails. You can’t pull anything down tight against the siding without bending or crushing it, risking large-scale cracking & water intrusion.
So the better idea would be to run some bolts into the stud, and then rigidly attach the hose hanger to them, set maybe 1/8 - 1/4 inch out from the siding face. That’ll need some more shade-tree engineering to sort out.
All in all, a MUCH better (and easier) idea to mount the hose hanger on a free-standing post you drive into the ground.
Well, if there’s nothing else nailed into the same piece of vinyl, then changing size won’t matter; it’ll just grow and shrink relative to the nail.
The nail gives me a problem, though. Buy some screws. Actually those hose hanger thingies come with screws. Look for them behind some tape on the aparatus somewhere, or behind the cardboard branding overlay.
My mailbox is hung on nails driven through vinyl siding. I did it myself, but I have to note that the previous owner had his mailbox hung on nails driven through the same siding. (Not to mention other fixtures, like the porch light.)
I’ve had no problems whatsoever with stretching or anything (Hey, tyhe siding is put in place with nails!) In order to minimize any possible problems with leaking, I filled in the old nail holes with RTV sealant, and put RTV sealant around the new nails I drove in.
Haven’t had any problems at all with it.