English ivy (Hedera helix) is an evergreen, perennial vine that was introduced from Europe and Asia and is not endemic in much of the United States. English ivy can be invasive and difficult to control once established. Four similar, but not identical, experiments were conducted in sequence to evaluate selected, POST-applied herbicides for English ivy control. English ivy plants were propagated from cuttings and container-grown to obtain a large population of uniform plants. Aminopyralid and fluroxypyr applied at 1.34 and 0.71 kg ae ha⁻¹, which is more twice the maximum registered rate for either herbicide, were ineffective. Glyphosate and 2,4-D amine were generally more effective, but neither herbicide provided a level of control that could be deemed consistently acceptable. Glyphosate applied at 8.51 kg ae ha⁻¹ (the highest rate evaluated) provided 69, 98, and 89% control in the second, third, and fourth experiments as determined by foliage fresh-weight reduction relative to a nontreated control. Treatment with 2,4-D at 5.60 kg ae ha⁻¹ (the highest rate evaluated) controlled English ivy 28, 98, and 89% in the second, third, and fourth experiments, respectively. Mixtures of 2,4-D and glyphosate were generally no more effective than were the components applied alone. Metsulfuron was the most effective herbicide. Metsulfuron applied at 0.168 kg ai ha⁻¹ controlled English ivy ≥ 97% across the three experiments in which this treatment was included. This treatment also prevented regrowth.

Nomenclature: 2,4-D, aminopyralid, fluroxypyr, glyphosate, metsulfuron, sulfometuron, English ivy, Hedera helix L

Management Implications: English ivy was first introduced into North America centuries ago in the colonial period. This species has been widely planted as an ornamental ground cover, but it can be invasive and difficult to control once established. Herbicide-based control has traditionally been only marginally effective, and eradication was never attainable. Six herbicides, plus two herbicide combinations were evaluated for English ivy control. Surprisingly, two relatively new pyridine herbicides that are used for the control of noxious and invasive species in pastures and rangelands, i.e., aminopyralid and fluroxypyr, were less effective than either glyphosate or 2,4-D. The sulfonylurea herbicides metsulfuron and sulfometuron were also evaluated. Metsulfuron was more effective than sulfometuron and was also more effective than either glyphosate or 2,4-D. Metsulfuron applied at 0.168 kg ai ha⁻¹ consistently provided ≥ 97% control, as measured by foliage fresh-weight reduction, and prevented any regrowth. Metsulfuron may have potential for English ivy control and eradication.