Help - 2 Dead and one more infected
I have a number of Hydrangeas in my sea facing garden in Co Kerry, Ireland. Planted some 6 years ago they have grown really well and form a spectacular show with blues, pinks in my weak but acid soil. Over the past 18 months 2 adjacent plants have died off for no apparant reason and 3rd adjacent one is showing signs. Perhaps coincidence but after being clipped back to super buds they wilted in spring. I think it must be Bacteria Wilt for which I understand from my research is incurable. See Photo. I cut back the stems and noticed they were mainly brown inside. When dug up the roots had semi rotted but a little life remained. The one that is showing signs of stress in the photo I have cut it back to the base and cleaned all the dead leaves.
I would welcome any feedback to a) stop it affecting any more plants and b) eradicating it from the soil so I can replant. Jeyes fluid came to mind but what strength, how long, etc