A: In some instances it is better to remove insect and disease infested plants rather than chemically treat them. Although the salvia will probably return in the spring it is too easy for the insects to get started on one plant and move on the neighboring foliage producing new colonies and infestations elsewhere. The cold weather has probably destroyed much of the insect population however is it possible some of the insects will survive and are waiting for the perfect environment to reproduce and increase their numbers. I would suggest pulling the plants up and start fresh next spring with insect free plants.
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