Q.rose of sherin
I have three rose of sherin trees in a row two of them bloom every year one of them is a bit smaller, but does get a lot of buds, but never blooms. Why?

Here is an article that will help: https://www.thespruce.com/flower-buds-on-my-rose-of-sharon-not-opening-2132265

First, please know they are ROSE OF SHARON. I once had this problem, became disgusted and decided to dig out the failing plant. I discovered that ten inches down was a huge amount of rocks and that is why the plant did not do well. It was planted over hidden rocks and needed more soil to really do its thing. Who knows...maybe that's your trouble too.