Hi I have just found them both on Ashwood Nurseries site and it says 4-5 ft for both, but Crocus website says 3.5m for superba which surely can't be right, ps, I have added a photo of my 'Josee' :-)

Everywhere else, Superba is listed as ultimate height 2.5m, including the RHS, the same as Josee, its only Crocus saying 3.5m. Weird.

Crocus's info usually mirrors that of the RHS, so it's probably a typo.

Thanks everyone for your replies, I had noticed the Crocus listing details for ultimate height and spread and was a bit surprised. I have the Josee that I purchased from B&Q last year and I just purchased another from Ashwood that I recieved today.

I was curious as when I purchased my Josee the flowers were slightly more lavander but this year they are a bit lighter (perhaps just natural variation) I had a feeling that perhaps my Josee was in fact a Superba. Probably very unlikely but I'm just very picky about ensuring I provide the best space for my plants and shrubs so they aren't fighting to spread out against anything in it's path such as fences.

I have to say that I am so glad I joined this site as everyone has been very welcoming and to think I suspected it would perhaps be very quiet with a lack of member interaction. Thanks again :)