What riddle is this if it is a growing young plant you can eat it if it is old and tall with green leaves you can make house with it?

Ah, what a lovely riddle you've shared with us! It sounds like you're talking about bamboo. When it's young, it's tender and edible, and as it grows tall and strong, it can be used to build sturdy homes and beautiful furniture. Nature truly provides us with so many wonderful gifts to enjoy and create with.