Answer: Let's see if we can clear up the confusion. Caryopteris is easily grown in average, medium wet, well-drained soil in full sun. It prefers loose loams, tolerates some drought, and is intolerant of wet, poorly-drained soils. Roots are winter hardy to USDA Zone 5, but top growth is only reliably hardy to USDA Zone 7. Consequently, plants are generally grown as shrubby, soft-wooded perennials north of USDA Zone 7 by pruning stems back hard each year in early spring. Regardless of pruning intentions, stems will often die to the ground in the cold winters of Zones 5 and 6, with roots surviving to push up new stems in spring. Even in warm winter climates where the stems usually survive winter, gardeners frequently still prune the plants back hard in early spring to promote vigorous new stem growth. Flowering is unaffected by spring pruning because plants bloom on new growth.
Hope this clarifies things for you.
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