Originally Posted by ZoeM

Many thanks everyone for your replies - I feel suitably chastised!

The odd thing is, that I have had 2 other box in pots for 7 years: I have never repotted them, never added any fresh compost, and I give them the odd seaweed/general plant food feed in the summer. And the pelargoniums have been very happy for the past 5 years, until I started giving them any attention!