Totally off the subject of fruit trees, but does anyone know what
might be causing lower part of arbor vitae to turn black, somewhat
shiny, but will not rub off; seems to be spreading; have tried
various fungicides, but doesn't seem to help; have also cut it out,
disinfecting shears?
Or, any other place to turn for help; have tried Googling, but still
no answers. Have also had some testing done.