From growing pollen-less varieties I can say they seem to last much longer. An individual flower seems to hang around two weeks or more without getting 'old'. But I haven't taken down actual dates, so.... Yellow Cocotte and Spring Pink don't seem to accept any pollen. Nothing I've tried works and the female parts are often composed of 4 or 5 carpels rather than 3. Even after the tepals finally fall (or hang on after becoming dry), the ovary - sometimes even the whole pistil - instead of shrivelling, remains green and firm.
Edit: Keith, I wouldn't be at all surprised if mine were lasting 3 weeks too - I just never keep track of time so I couldn't trust myself to say it was that long!
