I have an Acer palmatum ‘Orido nishiki’. This year the main stem of the tree at the top has gone white and black and all the stems that are leading off of it haave not leafed, although there are buds,where the rest of the tree has. can you tell me what this could be. I am really concerned that it could be a serious disease and that I will lose the tree.
The tree simply does a ‘cut back’, not being able to keep all parts going!
Sometimes a disease called coral spot exploits a struggling tree and causes the dieback.
Cut away any dead bits, mulch the root area with well-rotted leaves and give a light shake of potash or tomato food.
If and when, it settles down, it will re-grow from lower down.