Answer: In my experience the best times are early September and very early spring as soon as it begins to grow. These are also the best times to divide it. If you need to move it now, make sure it is well watered the day before, replant immediately and then keep it evenly moist (damp like a wrung out sponge, not sopping wet) while it re-establishes. You may also need to trim it back a bit to compensate for lost roots if it wilts badly after you move it.
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