I am trying to grow jungle trees. (Mega ones) 
I place my four sapplings and bone meal them and they won't grow no matter how much bonemeal is used.
This is happening in areas it should always grow in. I live in a mushroom island with areas I have changed out to grass. There is NOTHING around the sapplings I place but they still won't grow. I have tried doing it in many different biomes. 9/10 they won't grow up.  

The picture below is an example of an area I try to grow them in. There is nothing in the sky, nothing on the ground but I can try most areas and nothing will happen.

Have tested no other trees, but the small jungle tress mostly seem to grow fine.