Comparison of Invasive Shrub Honeysuckle Eradication Tactics for Amateurs: Stump Treatment versus Regrowth Spraying of Lonicera maackii

Elimination of Asiatic shrub honeysuckles (Lonicera spp.) from preserves and conservation areas in eastern North America is difficult because bird dispersal reintroduces seeds from shrubs in the neighborhood. To reduce this problem, honeysuckle control must be instituted on a broad scale and involve public participation. Many techniques for honeysuckle control are beyond the capabilities and inclinations of volunteers and local landowners. In a replicated study, we evaluated two suitable techniques and applied them in spring, early summer, late summer, fall, and winter 2009. These were stem cutting followed by painting with 18% glyphosate, and stem cutting followed by spraying of regrown shoots with 1% glyphosate about 40 days later. We regarded the spraying of regrown shoots as more practical for neophytes. Overall, cutting followed by stump treatment is more effective, killing 75–85% of individuals in spring and early summer, and >90% later in the year. Cutting and spraying regrowth was most effective in spring (56% killed), and poorer thereafter (20–40% killed). The result for spring was much lower than previously observed. Death rates for the cutting and regrowth spraying treatment were not affected by shrub size, but the amount of regrowth after spraying responded strongly to size. Cutting and regrowth spraying may be suitable in situations where reducing the competitive effects and reproduction of individuals is sufficient, or the resources to treat stumps with concentrated glyphosate are limited.