Washington

In the east, Japanese Barberry is on their list. It grows and seeds like weeds. Said to be invasive. But the birds love to nest in it, find dried berries all winter. Cutting barberry down, or pruning anyway, gives a pile of branches loaded with thorns that repel deer. They are commonly used to protect plants like spruce or white pine or blueberry from deer.

Dear decimate my ivy btw. Can't see as anyone needs to to anything to ivy.