20% garlon 4 in basal bark oil sprayed at the base of invasive Siberian elm, Ulmus pumila, kills these small elm trees growing in our prairie planting. Above is one dead elm. There is a small ring of dead, or at least wilted, herbaceous plants at the base.
Near this prairie planting, there are a few big Siberian elm trees that lofted seeds across acres. We keep top killing them with annual fire and they keep re-sprouting. Last year the crew applied a small amount of basal bark herbicide to thousands of these shrub sized trees and they appear to have all died.
Below is an untreated Siberian elm: