Unless sheltered naturally, young shrubs and other ornamentals may need some help making it through the winter undamaged. Fact is, newly planted ornamentals often need pruning, staking, bracing, wrapping and watering to thrive.
Pruning may be needed to remove broken or damaged stems or branches. On deciduous plants, pruning up to 25 percent of the leaf-bearing wood can reduce moisture loss from plants with limited root systems. It also thins the top and reduces top weight and wind resistance. Remove the whole branch, don't leave stubs, and be careful to preserve the tree's natural shape.
Some trees over 1 inch in trunk diameter and upright evergreens 4 to 5 feet tall and larger benefit from staking during the first year after planting. Staking keeps the root ball from rolling or pivoting in the ground when strong winds blow. Without support, the plant may have trouble establishing a sturdy, stabilizing root system and may begin to grow leaning away from the prevailing wind.
Place a single stake about 12 inches away from the tree on the side toward the prevailing wind so the wind pushes the tree away from the stake rather than toward it. If you’re using two stakes, put one on the windward side and the other opposite it. Three stakes should be spaced evenly around the tree and fastened together with horizontal braces to form a triangular structure around the trunk. Fasten the tree to the stakes with wire enclosed in a length of vinyl garden hose, soft rope or commercial tree ties. The tie should form a figure 8, with one loop around the trunk and the other around the stake and the cross between them.
Avoid using unpadded wire or cable around trunks or stems–it can cut through the bark and girdle the tree. Damaged bark can also heal and grow over the wire, making it impossible to remove without seriously damaging the tree. Staking should be done only temporarily–generally, stakes and guy wires should be removed after one season.
Because root systems are limited, newly planted trees and shrubs need plenty of moisture. Roots continue to grow into the fall, so, unless fall rains are plentiful, watering needs to continue until the ground freezes. You should soak the soil in the root zone every seven to 10 days during dry weather. Sandy soils may need more frequent watering than heavy clay or loam soils.
Bright winter sun can damage the bark of young plants and, combined with wind, dry the foliage of evergreens. Wrapping the trunks of thin-barked, smooth trees with burlap or special tree-wrapping paper shades them from the sun and helps prevent sunscald and bark splitting. To screen evergreens from sun and wind, tack canvas or burlap to stakes on the south and west sides of the plants.
Mice and rabbits may feed on tree bark in the winter. Rodent guards made of ¼-inch mesh hardware cloth need to extend from the soil to well above the usual snow line. Mice will gnaw on bark beneath the snow; rabbits can stand on top of frozen snow to damage tree trunks and lower branches, so guards need to extend at least 18 inches above the usual snow level.