This is a good example of the way in which data can be skewed by the use of certain criteria. I posted dozens and dozens of rose photos in March 2014 and dozens more in April. I didn't enter the photo contest, however, so the use of that criterion could suggest that I have no roses blooming before May (or at any other time, for that matter). Data can also be skewed by the method used in submitting photos to the database. Mine usually are imported from the forums, so there's no date showing on the images.
I think
@Calif_Sue and I have contributed the majority of rose photos, and by May our once-bloomers are almost finished for the year and our rebloomers can be entering their second flush. The timing of rose week therefore seems fine to me. In the past, rose week was always in February and even then we had no problems filling the week with photos and information.