Diagnosis
Diagnose: Butterfly Bush Winter Dieback
Use these observations to decide what to check next.
Cold damage to above-ground wood (winter dieback)
Begin at the crown, not at the cane tips. Firm tissue, swelling basal buds, or new shoots mean the root crown survived even when every exposed stem is brittle.
On questionable canes, make a shallow scratch from the tip downward and stop where moist green tissue or swelling buds begin.