What causes holes in the leaves of a butterfly bush and down towards the bottom of the plant? The stems are brown not green.
Certified GKH Gardening Expert
I suspect the culprit is slugs. They come out at night and disappear during the day. While you would not always see them, if you know for certain they are there or find evidence of their nightly visits, this should confirm the fact that they are munching on your shrub. This article will help:
As for the stems, this article will help determine if your shrub is still alive or not. If it is and the stems or roots are still healthy, the shrub should come back. https://www.gardeningknowhow.com/plant-problems/environmental/how-to-tell-if-a-plant-is-dead-and-how-to-recover-an-almost-dead-plant.htm