• Beth Kilgo

Wolf Creek Trout Lily Preserve: Invasive Species, Part One

Part one in a three part series on the invasive species in the Wolf Creek Trout Lily Preserve and surrounding areas. part one discusses the Japanese honeysuckle.This series goes with the series on the Preserve.

None of the pictures are owned by the author of the article.

There are several invasive species that threatened the wetlands and the trout lily slope, many of which, known by their common names, aren’t always thought to be invasive. Of those are Japanese honeysuckle, Chinese privet, and the inch plant, all are common names.

The Japanese honeysuckle is one of the plants that threatens the slopes the trout lilies inhabit and is an opportunistic invader that will take advantage of disturbance, insect damage, or tree gaps. While it provides winter forage for deer and is effective in controlling erosion, its ability to displace native plant species, as well as its relatively fast growth rate, have quickly become problematic.

Another threat passed by the Japanese honeysuckle is it’s dangerous for dogs. The stems and berries can cause nausea in humans; however dogs and other small mammals cannot process the chemicals fully.

The vine of the Japanese honeysuckle changes over its lifespan. When the honeysuckle is young, the vine is reddish and fuzzy. As it ages, it becomes hollow and has brownish bark that can peel in long strips. Japanese honeysuckle is fragrant and flowers in late April to July and sometimes in October. The flowers grow in pairs, and the flowers are first white in color but change to yellow over time. The Japanese honeysuckle grows black-colored berries in September through November. Japanese honeysuckle is often confused with the native species, the coral honeysuckle.

The coral honeysuckle is distinguishable by its upper leaves and red or orange berries. Coral honeysuckle has connate leaves, a single leaf the stem grows through, compared to the Japanese honeysuckle’s ovate-shaped leaf.

The Japanese honeysuckle can be spread by birds that consume the seeds in the berries or underground rhizomes or above ground runners. The rhizomes alone would be a challenge because they spread underground and store energy to ensure the plants survival in extreme conditions; however, the runners pose a similar problem. A runner is a portion of the stem that grows horizontally. The tip of the runner may produce buds that can become new plants. While gardeners may value the buds, they can be disastrous to wild plants, especially once established.

The Japanese honeysuckle threatens the natural diversity by preventing native species from spreading and growing. It can also cause more invasive species to take root. Japanese honeysuckle will twine around anything in close proximity and overtake small trees and shrubs, which may lead to their collapse. Additionally, they may form mats in the canopies, blocking light for all plants below.

The Japanese honeysuckle was introduced to America in 1906, and despite its uses, it’s still a threat to damaged native populations.