Creeping Hydrangea on Oak trees
A few years back I planted a creeping hydrangea near one of my oaks (in this case a healthy 80'er). A dear friend of mine, who knows a lot about these things (recently 'missed' in getting his certified tree expert designation) and who is a L.A. asked me what is more important? - the flowering (it has now creeped nearly 30' up the trunk with the caliper of the main hydrangea runner being 2" circumference) or the potential accelerated sickness or death to the tree. I know that I would never have ivy climbing up that oak, but thought that hydrangea wouldn't be a problem.
He says any plant like climbing like that will attract bugs which can eventually attack and weaken the oak - I recall this planting being very popular in Japan (though I don't recall the type of tree that it would run up).
Comments please: Will I eventually lose the oak if I allow the hydrangea to creep and prosper? Or is there no appreciable harm to the oak that will occur?