hibiscus question

Hi Hibiscus people!
In the past couple of years, I have given starts of tropical hibiscus to a friend. These were both double blooms..red and peach. They have done very well for him, but this year are reverting to single blooms. Can you tell us why?
Mine are still double.
Thanks for your help,
Marcy

Often the first blooms are single and as the plant matures the flowers will be the double form.

Thanks ardesia, but these are mature plants...so it's just the opposite.
The red one is about 8 ft. tall...not sure about the peach one.
Could it possibly be from NOT pruning them??

Sorry, I did misread it and thought they were rooted cuttings.

However, I still believe it is only the first (outdoor) blooms of the season that will be single. Give it a bit of time and I bet they will be double again. I had the same situation with one last year.

Ok thanks. I will tell him to see what happens from here.