Plants that are well maintained during the year (proper pruning, watering and fertilizing) and that are healthy will be better candidates for winter survival. Winter conditions can kill plants in many ways, even some cold hardy plants. Their tops or roots may freeze. Some evergreens that do not have enough water supply in the soil may dry out when subjected to persistent winds.
Boxwood (Buxus sempervirens) is a dark green evergreen native to southern Europe and northern Africa. It usually grows to a height of three to four feet in the Iowa climate, and is popular for borders and hedges because of its dense, dark green foliage. Boxwood requires fertile, well-drained soils and prefers wind protection if grown on an exposed site.
Fortunately, trees and shrubs have the ability to leaf out again if the initial growth is damaged or destroyed. Healthy, well established trees and shrubs should not be greatly impacted and will produce additional growth within a few weeks. Trees and shrubs planted within the past 3 to 5 years may benefit from a light application of fertilizer and periodic watering during dry weather.