So I just finished re-reading the LotR, and Sam recieved a box of dirt from Galadriel. He ended up planting a bunch of trees in the Shire, and putting one speck of dirt on each one. The trees then began to grow exceptionally fast and were very healthy.
So here is my suggestion:
Lothlorien dirt pouch. It would be a rare loot option, from chests or drops. It would act as super bonemeal, so it only takes one to grow any plant to maximum potential. For example, plant some wheat, use it once, and boom the wheat is fully grown. Or if you use it on a tree, it instantly grows up.
Alternatively, It could act like normal bonemeal, except that it degrades like a tool. This would be a high tier item, since it would be so useful. You could name it "Galadriel's Dirt" or something.
(i deleted the portion about the new dirt.)