Brown Spots on Buds of Rose of Sharon
We used fish emulsion late in the summer on our Rose of Sharon. It is covered with buds now in fall that have brown spots. Will it be alright or should I prune them all off? Will the plants survive our winter?
Fortunately fish emulsion is a slow release low nitrogen fertilizer. It probably had minimal if any negative impact on your plant. Fall after the leaves drop or early spring before growth begins are the best times to fertilize trees and shrubs. Wait a year to fertilize new plantings. Once established, properly watered and mulched trees and shrubs need little fertilizer. The weather or late season pruning could have stimulated late flowering. Cold temperatures probably caused the browning. You can pick off the buds or allow them to drop naturally. Your plant should be fine if the winter is not too severe.