Answer: In my experience, it is best to trim Perovskia atriplicifolia back by about two thirds in the spring to encourage new growth and remove any winter damage. Be patient with it because it begins to grow a bit late in the season. Its natural shape is upright but somewhat open and it will flop or spread out by late summer. Most varieties are rather large so you need to allow plenty of room for them. Move yours this fall, but don't cut them back until next spring, after the roots have had a chance to establish themselves.
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