I have a customer who has some overgrown boxwoods, both English and American. They have grown to about 8-10 feet and the customer wants them cut back. She wants them cut back to about 4 ft. By doing so it woulf pretty much leave the shrubs naked of any foliage. Will this kill the plants? In the past I have cut back other types of shrubbery, hollies, etc, with good success. I have never done it with boxwoods and was wondering if anyone out there has? I would really appreciate any input.