I've got some apple mint in a rectangular window planter. It measures about 24"x8", and about 10" deep.
The mint started getting really leggy and scraggly looking recently, and since it gets plenty of sun I'm thinking it may be rootbound. If it is, what can I do instead of putting it in a bigger pot? Which is not an option at this point.
Can I take something small, sharp, and saw-like and cut away the outer rootball by about 1/2 inch, in the shape of the planter, and just fill in the new space between the rootball and side with fresh potting mix?