I stopped fertiliser in later August when I read something here on OB that I should have already done so. These did start to form arround that time so I bet that's what they are.
Anyway, it's getting just rain water now and only a little of that when it's really dry. It's also in the greenyhouse which will only be heated to keep of frost and no more (currently unheated) so hopefully I'll get those flowers in the spring.