rose of sharon

Question

My rose of Sharon bushes get hundreds of buds but most don’t flower – why?

Answer 1

There can be a few reasons including environmental, to much or to little water.
Fertilizer issues also can cause this, again to much or to little.
Also Rose Of Sharon can be infected with a fungus call Botrytis and Thrips insects or even a combination of these 2.
A fungicide applied prior to buds forming can help.
Neem Oil is a good treatment since it works as both an insecticide and fungicide. It's safe for people, pets and beneficial bugs.

Here are some links for you.

https://www.gardeningknowhow.com/ornamental/shrubs/rose-of-sharon/rose-of-sharon-bush.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm