Answer:
The more you take away from me the bigger I shall get.
So cold damp and dark I am. To stay you would refrain yet those who occupy me do never complain.
What has banks but no money a bed but no sleep waves but no ocean?
Never ahead, ever behind, yet flying swiftly past, for a child, I last forever, for adults, I'm gone too fast.
I am flora not fauna. I am foliage not trees. I am shrubbery not grass.
I start with T end with T and within me is T.