Whilst the late summer/autumn flowering gentians like monsoon conditions, Susie, they don't like sitting in wet soil. In the garden the bulk of the rain will drain away quickly, but less so in a pot. If your gentian has been in the same pot for several years the roots could well have filled the pot and restricted drainage. I would suggets repotting it in the spring into a pot that will easily take all of the roots and potting up with a gritty compost.

Hi Bulbaholic,
Thanks for that, I had wondered about splitting it and putting some into the alpine garden which is around the top of the wall but thought they might dry out too much. Will take your suggestion on board.

Sue

We mainly grow ours in the garden, Susie, a few in pots. If you can split it successfully then why not try both?