I grew a few evergreens in Utah, where we had a LOT of snow. They became dormant after a while, but I bought them from someone in Utah who had been growing them for a few years already. They adjusted to their environment, and I never had any loss. I never cut the foliage, but mulched well. I never put the mulch over the plant, but it would migrate to the middle of the plant over winter, so I would have to pull it back in the Spring when the snow started to melt. I removed the old leaves off at that time. I think the leaves gave the plants a little extra insulation.
