How to fix a vinyl fence that is coming out of the ground?

sounds like the ground is heaving from the freeze/ thaw cycle and the posts are following the ground movement or they are rotten. They may need replaced. If you need to replace them, make sure the posts are put below your frost line.

It's coming out of the ground because it was improperly installed. Essentially you have to remove the fence and reinstall it deep enough. Answer this Hometalker's question!

Frozen soil expands and can push fence posts right out of the ground. Fortunately, there is an easy vinyl fence repair for frost-heaved posts. Pull the posts out of the ground, and then dig the post hole deeper so it’s below frost depth. (If you’re doing this repair in winter, you may need special equipment to dig into frozen soil, such as a pickaxe or heater.) Make the hole wider at the bottom than the top and fill the hole with cement after you re-insert the fence post. This vinyl fence repair will keep the post from popping back up because it will have to fight its way through frozen ground.

Thank you for your advice.