I have 8 spartan junipers and they have had a rough go this past winter as we had a very bad ice storm at Christmas, in Toronto, Ontario, Canada. Most are about 25 feet high and have been growing nicely for the past 25 years. The newest one is 12 feet high and has turned completely brown. The bigger ones show signs of turning brown too, but still have lots of green. I have bought fertilizer spikes for evergreens and hammered them in and watered the trees. How can I stop the "browning" from progressing further?