Answer: Butterfly bushes are not terribly picky about soil as long as it is reasonably well drained and they are in a sunny spot. If they are in a very windy spot you might consider some type of wind barrier to help them overwinter better, but apart from that the winter protection would consist of several inches of mulch over the root zone. If the fall is dry, make sure they go into cold weather well watered. An application of compost and/or a balanced general purpose fertilizer (such as 10-10-10) according to the label instructions would be a good idea in early spring. Mid spring is also the time to see how much winter damage has occurred and to trim them back to remove any winterkill and for shaping. They may die back to the ground in a hard winter but will regrow quickly from their root system.
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