I have a Primula allionii Broadwell Milkmaid which was given to me about 3 years ago, when the plant was about 8-9 years old ( I think? ) . I have been in the process of removing the dead leaves this afternoon, a rather long winded job that I have not yet finished. The plant seems to have lost some of its vigour ( not surprising in view of how prolifically it flowers every year), and some of the stems are a little thin. Do allionii types respond to cutting back, like I think some P. marginata types, and if so when?