Answer: Based on your description I think the evergreens have suffered some winter damage. Hopefully they will refoliate nicely this summer. In the meanitme you can trim off any dead twigs or branch tips. Dead wood will be gray or dull brown, brittle and snap off in your fingers. Live wood is supple and has green just inside the bark.
To minimize the chances of winter damage happening, it is best to plant them in a sheltered location with protection from winter winds, make sure the soil is kept evenly moist any time it is not frozen, and use a year round layer of organic mulch over the root area. The mulch should be applied in a flat layer two to three inches thick over the root area but should not touch the trunk.
Butterfly bushes are considered to be dieback shrubs in your area, meaning they will suffer winter damage and may die back to the ground as a result. Butterfly bushes are pruned in the spring. Cut it back to about 12 to 18 inches tall, or even shorter if needed to remove all winter damage. Then be very patient waiting for new growth the begin in mid to late spring when the soil warms up. Butterfly bushes have the best chance of winter survival if planted in a location with very well drained soil.
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