A large rhodo (name unknown - see flower below) has some of its buds turning brown and eventually shriveling and turning black. The buds were healthy looking until the last couple of months when the browning started. It always did that for some buds but this year is particularly bad. An adjacent rhodo (white in the background) is totally unaffected. I was giving it some fertilizer in the past but not in the last couple of years. Last year l spread about 4cm of soil amender at its base. There was also the draught of course and did not water it as much as l would have normally due to the restrictions. I am hoping that it is not a virus. After the buds turn black, they do become 'hairy'.