Why are my bottle brush plant leaves turning red and falling off?
I have a mature bottle brush plant in a very large pot on my patio this year. It has leaves that are turning red and falling off and it looks like it's going to flower as it has for the years previously. We live in South Yorkshire and this winter we had the beast from the east, plus two lots of heavy snow. It is about five foot tall and the stems seem to be hanging down. I have treated it with a copper fungicide but have not solved the problem, so I am at a loss as to what to do now.
It sounds like it is getting rootbound in container. You will have to do some root and top pruning to be able to keep it in the same container, or repot it into a larger one. This will correct the issue.
This article will guide you on how to root prune properly: https://www.gardeningknowhow.com/houseplants/hpgen/prune-roots.htm