rose of sharon

Question

I have a white rose of sharon (a beautiful shrub, my fav.). I also have other coloured ones that are beautiful as well but I love the white best. Anyway, my white one is about 18 years old and over the past, say, 5 years, a part of it doesn’t look healthy. The leaves are not as green and not as many flowers. The leaves also turn yellow much earlier than the rest of the plant, but the strangest thing is when it flowers there is no maroon colour in the middle. What do you think? Is it new growth? Or should I just cut that section out completely?

Thanks – Dave

Answer 1

One possibility is that this branch is a "sport", a genetic mutant which occurs on part of a plant, changing its coloration or other characteristics:
https://www.gardeningknowhow.com/garden-how-to/info/plant-sport-mutations.htm

Another possibility is that this is caused by environmental differences. The pigments in hibiscus flowers can actually fade in excessive heat or bright sunlight. If the different branch is exposed to more direct sunlight each day, this could be the cause.

You could either leave the branch on or prune it off, either will be fine. If you want to see whether it's a "sport", you could try taking a cutting.