If you have small azaleas growing outdoors you started from cuttings, they may need winter protection. They probably don't have a root system sufficient to carry them through prolonged freezing weather.
The best protection is a windbreak, shade from the sun, and plenty of moisture in the soil.Azaleas and other evergreens lose moisture from their leaves during the winter as well as in the summer. When exposed to wind and sun, the moisture lose is much greater, and cannot be replaced by the roots as fast as it is lost. Damage is certain to occur, particularly when the ground is frozen.
Protection also is a good idea for other newly planted evergreens. Damage is possible although normally hardly, they are not well established in the new location.
In addition to a windbreak and shade, a much of leaves, straw or some similar material will help prevent the soil from freezing deep.
The mulch has an important influence on soil temperatures.The soil remains warm enough in the fall for roots to continue growth long after top growth is over. The newly planted tree or shrub has more time to develop a good root system capable of anchoring it in the soil and supplying the top with moisture.
In early spring the mulch should be removed; it would make the soil slow to warm up. In early spring, newly planted trees and shrubs should not be mulched.
Will covering a plant protect it from cold weather? Some experts say yes, others no. It depends on the plant and how it's covered. If an evergreen is covered and gets no light, it cannot produce food for the plant.
Some experimental work in Georgia indicates that covering azaleas with clear or black plastic can cause more damage than no covering at all. Researches elsewhere found the opposit - they found it effective to cover the plants with plastic, bringing it all the way to the ground and covering the ends with soil to hold humidity inside around the plants.
Rutgers University specialists say that little tents of plastic can kill a plant deader than any January weather. The reason is the plastic acts like a greenhouse during sunny days. The plant inside may start new growth and disaster is sure to follow.
A windbreak on the breezy side to prevent drying out by the wind, and shade on the sunny wide are about the best protection you can give, Rutgers Specialists say.