What is killing my PG hydranga
Could voles have killed my PG hydranga. It is 15 years old, 7' tall and always beautiful and healthy. Is in full sun and hardly ever even watered it. This year it is dead and my neighbors (who never waters anything ever) is in beautiful shape. I took a piece that still had a couple of half dead leaves on the end (rest is just dead branch) to the local nursery and since he could not find signs of bacteria or fungus he asked if we had voles. We do and he said maybe voles tunneled to the roots of the tree and is draining water away from it. He said to spray castor oil around the whole area with the hose attachment to get rid of them but not at 80 drgres or over and it has been hot and seems it is going to stay over 80.
We also have moles and chipmunks and squirrels, etc. We have been overrun this year with wildlife including woodchucks, fox, coyotes, racoons.
Please, any thoughts. Will it come back or do I have to take it out? I wish I could try the castor oil but do not know when or if the heat wave will be over this summer.
Thank you for any help.
PS could you do it at night when it is under 80 even though the next day would be 80?