Evergreens are able to stay green in winter because they still photosynthesize and take up water. If the soil is frozen, water is less available. To compound the problem, the plants continue to lose moisture from the bright winter sun and cold winds. Without water for the roots to take up, drying and browning occurs.
Deciding if Dead
If you are seeing bronze needles, they will most likely green up again soon. If you see brown needles, they are dead, but the plant may still recover. If new growth is coming in behind the dead parts, the plant will cover up the dead areas over time. Depending on how much brown there is and how much unattractiveness you can tolerate, you may be able to prune the dead branches or tips. Yews will tolerate heavy pruning or shearing, but it can take several years for it to look good again. Some evergreens, including spruce, pines, and fir, do not handle pruning well. Boxwood and arborvitae can handle limited pruning. If you have damage in Junipers, prune back to a side branch. If they are pruned back too far they may not recover. Early spring through early summer is the recommended time to prune evergreens because new growth will cover pruning cuts and make them less obvious. If the plant is still looking bad by midsummer, and the new growth isn't covering up the dead, you may want to make arrangements to replace it. To prevent damage to your evergreens in future winters, especially those in exposed sites, you can wrap burlap around your yews or other evergreens. After droughty summers and falls, evergreens should also be watered at least 1 inch per week so they are well-hydrated for winter.
