I am new to this forum and have spent some years trying to grow my sea facing garden. My Hydrangeas have been a great success but 2 very healthy ones have died over the 18 months and another (all adjacent shrubs( is looking very poorly. The dead ones looked very healthy after pruning with great buds but then died away in the spring. Please see photo. Apart from this summer the past 2 years have been extremely wet here. Hopefully with your help I can eradicate the problem and stop it spreading to the rest.