Okay, this is for real not a joke. My Sapling has been growing in the island for 1 REAL LIFE DAY! I don't know if its a glitch, or something.. but what I do know is that its by Pumpkin seeds and melon seeds.. but not on them. :confused:
Do you know bones? Well put one in a crafting table and the bone will craft bonemeal. Then right click the sapling (with the bonemeal in your hand) a couple of times, quickly and it will grow.