The message
from "Furby" contains these words:

I have heard that you should always double up on grow bags. I.e. one on top
of the other (so the roots have more room to grow)

Not very economical on bags but what my Mother always did was to
cut them in half and use each half as one would a flower pot.

Also is it me or have grow bags got thinner over the years , I seem to
remember them being the same size a 75L bag of compost.

I thought that when I saw some yesterday ...

Jennifer