Is there a rule of thumb for the depth of ground cover (say chips or mulch) that will kill alder or Hemlock. One wild cherry also died.
Not trying to kill, trying to decide if 6" cover did in a bunch of alder/hemlock or if a combo of the 2001 earthquake follwed by ice storm is the main culprit. D.Fir seemingly not effected in areas with same ground coverage except obvious broken tops from the ice storm. Degradation of the trees started to be observed in 2002.
BTW, there are other nearby areas with lots of alders with dead tops (no recent moth infestation either) so am inclined to think EQ + the rare ice storm.
Not trying to kill, trying to decide if 6" cover did in a bunch of alder/hemlock or if a combo of the 2001 earthquake follwed by ice storm is the main culprit. D.Fir seemingly not effected in areas with same ground coverage except obvious broken tops from the ice storm. Degradation of the trees started to be observed in 2002.
BTW, there are other nearby areas with lots of alders with dead tops (no recent moth infestation either) so am inclined to think EQ + the rare ice storm.