I noticed that my azaleas in front have all very dark black stems---all the way from the ground upto almost the end of the stems. The ground below each plant is covered in stones and the stones too have turned all black. Is there anything that I can do other than removing them? Does the soil then remain a problem and make it difficult to grow other things there now? Thanks for your advice.
Certified GKH Gardening Expert
It sounds like Sooty Mold on your Azaleas.
This is caused by pests or insects on your plants.
Try to identify the pests involved and follow the treatment in the link below.