My 9 Rose of Sharon bushes changed from simple flowers to compound flowers this year. They were about 5 years old and close to 10 feet tall. Late last summer in August, all the buds turned brown but did not fall off the bush. The leaves looked perfect. This year, they are all blooming again, but all blooms are compound. I wouldn’t mind except the humming bird is avoiding them whereas they were all over my simple flowers. Do you know what caused this? Is there a way with fertilizer to reverse this?Thank you.
This is not unknown with Althea. HERE’S a link to more on that. You might try pruning it back to see is you can encourage a return to the original flower but you might also get something else entirely.