Q.Bamboo health
The base of the clums on my clumping bamboo is turning black. I fear I could lose the plant. I also see a white cotton looking growth on some of the stems. Do you know what this could be and how I can treat it?
Thank you
Robin

It sounds like Sooty Mold that is caused by an infestation, likely Scale or Mealybug from your description.
This article will help you.
https://www.gardeningknowhow.com/ornamental/foliage/bamboo/bamboo-plant-diseases.htm