Removing invasive honeysuckle is necessary for restoring native ecosystems. Common varieties like Amur honeysuckle (Lonicera maackii) and Japanese honeysuckle (Lonicera japonica) have aggressive growth patterns. These non-native shrubs and vines leaf out earlier and retain leaves longer than native plants, shading out the forest understory and preventing the growth of other species. Uncontrolled growth creates dense thickets that reduce biodiversity and can release chemicals that inhibit neighboring plants (allelopathy). Eradication requires persistence and a multi-year strategy to overcome the plant’s ability to re-sprout and spread.
Mechanical Removal Techniques
Mechanical removal is effective for small infestations or where herbicide use is restricted. Seedlings and small plants (less than one inch in diameter) can be managed by hand-pulling, especially when the soil is soft and moist. Ensure the entire root system is removed, as any fragments left behind can lead to re-sprouting.
For larger, established shrubs, specialized tools like a weed wrench or a shovel provide leverage to extract the entire root ball. “Root docking” involves cutting the lateral roots away from the main root crown using a tool like a Pulaski axe or a grub hoe. Once severed, the plant’s crown can be tipped over and removed, effectively preventing re-sprouting without chemicals.
Chemical Control Strategies
For large, dense, or mature honeysuckle populations, chemical control is the most efficient long-term solution. The cut-stump treatment is recommended for established shrubs with stems greater than one inch in diameter. This method involves cutting the stem horizontally close to the ground and immediately applying a concentrated herbicide solution to the freshly cut surface.
The application must target the cambium layer (the ring beneath the bark), which transports resources downward into the root system. A 20-50% solution of glyphosate or a 20% solution of triclopyr is commonly used; adding an approved dye ensures every stump is treated. Basal bark treatment is an alternative for shrubs with intact stems, especially those with thinner bark or where cutting is difficult. This technique involves applying an oil-soluble herbicide (like triclopyr ester) mixed with a penetrating oil carrier, to the entire circumference of the lower 12 to 18 inches of the stem.
Foliar spraying, where diluted herbicide is sprayed directly onto the leaves, is reserved for widespread, dense mats of Japanese honeysuckle or for treating small, uniform new growth after an initial cutting. When performing foliar applications, minimize the risk of herbicide drift onto non-target plants by avoiding windy conditions and using low-pressure sprayers.
The Importance of Timing
The plant’s biological processes dictate the most effective window for herbicide application. The period from late summer through late fall is the most successful time for chemical treatments. During this time, honeysuckle retains its leaves longer than native plants and actively translocates energy (sugars) down to its root system for winter storage.
Applying herbicide during this downward flow ensures the chemical is carried directly to the root crown and root system, maximizing uptake and resulting in a complete kill. This late-season timing minimizes harm to dormant native vegetation, making the honeysuckle an easily visible target. While mechanical removal can be performed year-round, manual labor is easier when the soil is soft and moist from seasonal rains.
Long-Term Management and Monitoring
Successful eradication requires a long-term plan extending beyond the initial removal. Continuous monitoring is necessary because the honeysuckle seed bank can remain viable for several years, leading to new waves of seedlings. Repeat visits for at least two to three years are recommended to hand-pull new sprouts before they establish a root system and produce seeds.
The disposal of removed plant material must be considered to prevent re-establishment. Honeysuckle branches and vines can root where they touch the ground, and berries contain viable seeds, so leaving piles of debris is not advisable. Removed brush should be chipped, burned, or hauled away to a disposal facility. Site restoration is the final step, involving planting native, non-invasive species to fill the void. Introducing native groundcovers, shrubs, and trees will outcompete new honeysuckle seedlings for light and resources, creating a natural barrier to future invasion.