Posted: 11/09/2012 at 13:27
If they all opened at the same time the flowering season would be very short, I think I read somewhere that each flower lasts a day or so, so they prolong flowering by opening up one at a time over a longer period.
There probably is a way of increasing flowering though but it's interesting to note that a stressed plant will produce more flowers than one in particularly fertile soil. If you are feeding it, make sure it is a Potassium based feed, a feed with too much Nitrogen will produce lots of leaves but will not encourage flowering.
Hope this helps, the flowers are so beautiful.