Thanks Paul and Steve,
Good to know that I don't need to worry yet
. It only has one plump bulb and one tiny, hardly worth mentioning bulb.
I had it out in the greenhouse until I read on this forum about a week ago that a cool room in the house would be better.
I let the greenhouse get quite cold (I aim for 5C but it's been down to 3C already this year) because I keep some cool growing orchids in there. The room I've moved it into is not being heated and I keep the door shut to keep it cooler , I try and keep it at 10C-15C but I've only bought a min/max thermometer today so not sure what I'm actually getting.
If I didn't dry it enough, early enough on, could that also affect it. While it was in the greenhouse I had started trying to dry it, but then had several days over a two week period when work in the greenhouse meant I had to put everything outside during the day and it rained heavily every day it did that. The old bulb it had when I bought it went soft and almost mushy at that point and I had to remove it for fear it would spread to the rest of the plant.
I have it dry now (and for the last couple of weeks) but I wonder if that could be a problem.