Why Is Japanese Honeysuckle Bad

If you’ve ever admired the sweet smell of Japanese honeysuckle on a summer evening, you might wonder, why is Japanese honeysuckle bad? While its fragrance is lovely, this plant is a highly invasive and harmful species that causes serious problems for native ecosystems. As a gardener, understanding its impact is the first step to protecting your local environment.

It was introduced to North America in the 1800s for ornamental use and erosion control. Unfortunately, it escaped cultivation. Its aggressive growth allows it to outcompete and smother native plants, leading to a loss of biodiversity. Let’s look at why this plant is so destructive and what you can do about it.

This vine grows rapidly, forming dense mats that blanket the ground and climb over shrubs and trees. It blocks sunlight from reaching seedlings below, preventing forest regeneration. This creates a “green desert” where few other plants can survive.

How It Harms Native Plants and Trees

Japanese honeysuckle doesn’t just grow; it conquers. Here’s how it directly harms your garden and local woods:

Light Deprivation: Its dense foliage creates a canopy that starves native wildflowers and tree seedlings of essential sunlight.
Resource Competition: It aggressively competes with roots systems for water and soil nutrients, often winning the battle.
Physical Stress: By twining tightly around tree trunks and branches, it can girdle and eventually kill young trees and shrubs through constriction.
Altered Soil Chemistry: Some studies suggest it may change soil conditions to further disadvantage native species.

Negative Impacts on Wildlife and Ecosystems

While birds eat its berries, the overall effect on wildlife is negative. The berries are less nutritious than those of many native plants they replace. By removing the diverse native understory, it reduces food sources and shelter for insects, birds, and other animals, disrupting the entire food web.

Why It’s So Hard to Control

This plant is a survivor with several unfair advantages:

Vigorous Growth: It can grow over 30 feet in a single season.
Multiple Reproduction Methods: It spreads by seed, which birds distribute, and by rhizomes (underground stems), forming new plants yards away from the original.
Rooting at Nodes: Wherever a stem touches the soil, it can root and start a new plant, making it incredibly persistent.
Tolerance: It thrives in sun and shade and tolerates a wide range of soil conditions.

Identifying Japanese Honeysuckle

Correct identification is crucial. Look for these features:

Leaves: Oval, opposite leaves that are semi-evergreen (stay green late into winter).
Stems: Young stems are hairy and reddish, becoming woody and hollow with age. They twine clockwise.
Flowers: Fragrant, tubular flowers that are white to yellow, appearing from late spring through summer.
Berries: Small, glossy black berries that form in the fall.

Be careful not to confuse it with native honeysuckles, which often have solid stems and flowers that are red, orange, or pink without turning yellow.

Step-by-Step Guide to Removal

Removing Japanese honeysuckle requires persistence. The best time to start is late fall or winter, when native plants are dormant but the honeysuckle leaves are still visible.

Step 1: Manual Removal for Small Infestations

Wear gloves. Using pruners or loppers, cut all the vines at the base.
Carefully untangle and remove all the cut vines from trees and shrubs to prevent them from re-rooting.
Dig out the root crown and as much of the root system as possible. Even a small piece left behind can regrow.
Place all plant material in black plastic bags, seal them, and solarize in the sun for several weeks or dispose with your trash. Do not compost.

Step 2: Dealing with Large or Established Patches

Cut the vines as described in Step 1.
Immediately treat the freshly cut stumps with a concentrated glyphosate or triclopyr herbicide, applying it directly to the stump with a brush. This is the most effective method for killing the root system.
Monitor the area every few weeks for regrowth. Spot-treat any new sprouts with herbicide or dig them out immediately.

This process will likely need to be repeated over two or three growing seasons for complete control. Remember, patience and consistancy are key.

What to Plant Instead: Native Alternatives

Once you’ve cleared an area, replant with native species to prevent its return. Here are excellent alternatives that support wildlife:

Trumpet Honeysuckle (Lonicera sempervirens): A gorgeous native vine with red trumpet flowers that attract hummingbirds.
Crossvine (Bignonia capreolata): A vigorous native vine with stunning orange-red flowers.
Carolina Jessamine (Gelsemium sempervirens): Offers beautiful yellow, fragrant flowers in early spring.
Native shrubs: Consider planting viburnums, serviceberries, or blueberries to fill the space with beneficial plants.

Frequently Asked Questions (FAQ)

Is all honeysuckle invasive?
No. Native honeysuckle species exist and are beneficial. The problem is specifically with non-native species like Japanese honeysuckle (Lonicera japonica) and Amur honeysuckle (Lonicera maackii). Always check the scientific name.

Can I just keep it trimmed in my yard?
It’s not recommended. Trimming won’t stop it from spreading by seed or underground runners. Birds will carry the seeds into natural areas, causing harm beyond your property line. Complete removal is the responsible choice.

Does Japanese honeysuckle have any benefits?
Its primary benefit is its fragrant flower, which is enjoyed by some. However, the ecological damage it causes far outweighs this single positive trait. The native alternatives provide similar beauty without the harm.

How does Japanese honeysuckle spread so quickly?
It uses a “double strategy.” Birds eat the berries and spread the seeds far and wide. Simultaneously, its runners creep along the ground and root at nodes, creating dense colonies that choke out other plants locally.

What if my neighbor has it growing?
Have a friendly conversation. Share what you’ve learned about its invasive nature and the threat to local parks and woods. Offer to help them remove it or suggest the native alternatives listed above. Community effor is often needed for effective control.

By choosing to remove Japanese honeysuckle and replace it with native plants, you are making a direct, positive impact on your local environment. Your garden can become a sanctuary for wildlife and a showcase for the beautiful, resilient plants that belong here. It’s a rewarding task that protects our natural heritage for future generations.