
If this happens, the item is gone for good.

"Consumable" items will be deleted if left on the ground anywhere outside your tent for long periods of time, regardless of where they are.There is a system in place to ensure that stuff does not lie around forever. There are two systems at work that will possibly move or destroy items lying on the ground. If it disappears, it shouldn't be permanently lost-you should receive it back in your mailbox on the next Campaign Day. Shifts in the island's layout may slightly relocate such an item, or may make it disappear.We wouldn't design such an item and then make you keep it in your backpack/storage for safety! If it was specifically designed to be kept on display (pets, trees, flowers, furniture, etc.) then you should be able to leave it on the ground without worrying about permanently losing it.Please see this page for more information. Shells on the ground will prevent new shells from spawning, regardless of whether they're in your tent or outside.In prior versions inside the tent is no safer than outside the tent. Note: Version 4.0.0 made it safe to leave these items on the ground inside your tent.

Basically, if it isn't a pet, plant, or man-made structure then it's not safe if you leave it lying around outdoors on the ground. (anything that wasn't specifically designed to be left outside on display) that are left on the ground anywhere outside your tent will eventually get deleted by the game. Shells, food, wood, imp essences, etc.
