I bought a very large Agapanthus from the garden centre back in September. It's called White Heaven. When I bought it, it had a flower stem of nearly 36" which was nearly over and when it finally died in December I cut it off/down. I have kept it in our conservatory which faces West and has underfloor heating. Since then it has had quite a few leaves turn yellow, and I would appreciate it if you could tell me whether I am overwatering or underwatering it, but it now has a flower stem some 14" tall and the buds are beginning to develop and spread out.