Do you HAVE to glue it together?

[Mooch]

This is a real stupid question, but I'll ask it anyway. Do you HAVE to glue it together? Granted, it won't "migrate" shapes while glued, but does it leak if it's not glued? It already seems pretty tight. It seems that the glue just stiffens the shape. Plus, if it's not glued, then you can take it apart if the roots begin growing down into the piping!
Monty the Mooch

[Ron]

I don't glue sections together in my larger gardens. I never glue the over flow pipe. But if you don't glue the tees with the bottles, the weight of the plants will eventually make the bottle and plant fall over and if you have a few of these falling left and right then you got a mess on your hands. If you built a cradle to hold them up then it might work.
Ron