Wondering what people's thoughts are on the advisability of planting hemlock in east-central Vermont, about 1400' elevation and at the border between zones 4a and 4b. Obviously in the past that would have been an ideal setting, but I'm wondering about the progress of the wooly agelid (sp); we want an evergreen screen from a road, and I don't want to plant hemlock now only to have the little critters creep up into central Vermont within 5 or 6 (or even 15) years and kill all the trees. Thoughts? Is it crazy to consider planting hemlock anew? Or at that zone and elevation do you think we're safe for decades to come?