Will Japanese Honeysuckle Kill Plants?

Growth Characteristics

• Japanese honeysuckle grows either sprawling along the ground or clambers upward on shrubs, trees and building structures. As a ground cover it's about 2 feet tall but 30 feet wide. When climbing up on other plants, it reaches 15 to 30 feet high. This easy-to-grow, soil and light-tolerant species sprouts from seed or its vining stems root where they come into contact with the soil.

Competitive Advantage

• Fast growth and huge number of seeds makes Japanese honeysuckle so successful as a rampant weed. It will grow in the dapple shade in forests, covering wildflowers and shrubs so they cannot photosynthesize light, thereby choking them out. Once a tree falls, the immediate burst of sunlight allows the honeysuckle vine to quickly grow upward, increase flowering and set seed. Birds relish the honeysuckle's seed, consuming them and dispersing them all around the landscape in their droppings. In regions where winters aren't colder than roughly 15 degrees Fahrenheit, Japanese honeysuckle remains evergreen. This constant shading prevents other plants' seeds from sprouting or benefiting from warming rays of the sun in early spring.

Growth Limitations

• Japanese honeysuckle seeds tend to overtake areas of barren soil that is evenly moist and basking in sunlight. If the soil is dry or too shady, seeds don't germinate well and exposure to untimely cold or wildfire kills juvenile seedlings, according to the U.S. Forest Service. Moreover, plants do not persist or establish on coarse, sandy soils or in nutrient-lacking peat ground. In forested areas where native vegetation is thick and shades the soil, Japanese honeysuckle doesn't establish well. Likewise, on a dense grassland, the native grasses prevent seeds from reaching soil and readily germinating. Once bare, moist soil and ample light marries, dormant honeysuckle seeds or tiny seedlings quickly grow and then take over.

Garden Containment

• Although beautiful when in bloom, gardeners must remain vigilant if a Japanese honeysuckle grows on their properties. Cultivars may also become weedy problems, especially Halliana. Mulch or hoe the soil to kill seedlings, or destroy plants and plant American native honeysuckles instead, such as Lonicera sempervirens. Do not allow seedlings of the Japanese honeysuckle to escape the confines of your garden, especially if it abuts a forest edge or abandoned property.