Japanese honeysuckle vine (Lonicera japonica)

 

Japanese honeysuckle vine (also known as golden honeysuckle vine or Hall’s honeysuckle) is a vine, unlike the non-native bush honeysuckles (Amur, Morrow, Tatarian, and Bell’s honeysuckles). Japanese honeysuckle vine is a perennial, woody vine that can cover other vegetation. It is an early detection plant in Minnesota.

Description

Appearance

Japanese honeysuckle vine is a vine that can reach 30 feet or longer. It can develop a woody stem, and the vine can grow over shrubs and trees.

Leaves and stem

Leaves are attached to the stem in pairs opposite one another. Leaves have smooth edges and are 1-3 inches wide and 1-3 inches long. Younger leaves can have lobed edges. In warm climates, the leaves can stay green through the winter, but in colder climates it will lose its leaves before winter. The stem can become woody as it gets older and larger. Young stems have hairs and are a reddish color. The vines twines around other plants; they do not have any tendrils or adhesive disks as some other vines do.

Flowers

Flowers are attached to the stem in pairs. Flowers are tubular – the petals are fused making it look like it has a top lip and a bottom lip. Flowers can start white in color but turn to yellow as they age. Flowers are generally about 1.5 inches long. Plants bloom from June to July.

Seeds

Fruits ripen in the fall. Ripe berries are deep purple to black in color. Berries are found in pairs and are each ¼ inch wide. Each berry contains 2-3 small brown seeds.

Rhizomes and roots

It can spread by rhizomes (an underground stem that sends out roots and shoots) and runners/stolons (above ground stems that spread horizontally). Roots are fibrous.

Biology

It is a perennial vine. It reproduces sexually with fruits. The fruits can be spread by birds or other animals. It can spread vegetatively through rhizomes and runners. It can be found in forests as well as in more open habitats like prairies and roadsides.

Origin and spread

Japanese honeysuckle vine is native to Japan, Korea, and eastern China. It was introduced to the United States in 1806 as an ornamental plant. While ornamental plantings have been found in Minnesota, Japanese honeysuckle vine is considered an early detection plant in Minnesota and the goal is to prevent it from spreading into natural areas. It is regulated by the Minnesota Department of Agriculture as a Prohibited-Eradicate Noxious Weed so any plants found are high priorities for management and must be removed. Refer to EDDMapS Distribution Maps for current distribution.

Don't be fooled by these look-alikes

  • Non-native bush honeysuckles (invasive) including Tatarian honeysuckle (Lonicera tatarica), Morrow's honeysuckle (L. morrowii), Bell's honeysuckle (L. x bella), and Amur honeysuckle (L. maackii) – Japanese honeysuckle vine is a woody vine while the bush honeysuckles grow as shrubs. Japanese honeysuckle vine flowers are white to yellow while the non-native bush honeysuckle flowers are pink (and occasionally white to red).

  • Fly honeysuckle, Lonicera canadensis (native) - Fly honeysuckle and other native Lonicera have solid stems while the older stems of non-native honeysuckles (including Japanese honeysuckle vine) usually have a hollow brown pith or core in the center of the stem. Fly honeysuckle is a shrub, not a vine. Both fly honeysuckle and Japanese honeysuckle vine have yellow flowers.

  • Bush honeysuckle, Diervilla lonicera (native) - This native honeysuckle has elongated capsules for fruit rather than round berries. It also has toothed leaf edges and solid stem centers. Fly honeysuckle is a shrub, not a vine. Both bush honeysuckle and Japanese honeysuckle vine have yellow flowers.

  • Native vining honeysuckles (native): wild (limber) honeysuckle (Lonicera dioica), hairy honeysuckle (Lonicera hirsuta), and grape honeysuckle (Lonicera reticulata) – In the native vining honeysuckles, the leaves directly below the flower are fused (making it appear that the stalk is piercing through a leaf), while Japanese honeysuckle vine has no fused leaves.

  • Round leaf bittersweet, Celastrus orbiculatus (invasive) – Round leaf bittersweet leaves attach to the stem in an alternating fashion one at a time while Japanese honeysuckle vine leaves attach to the stem opposite one another in pairs. Round leaf bittersweet produces red fruits surrounded by a yellow capsule while Japanese honeysuckle vine has purple/black fruits.

 

 

Regulatory classification

This species is a Minnesota Department of Agriculture Prohibited - Eradicate Noxious Weed meaning that the above and below ground parts of the plant must be destroyed. Additionally, no transportation, propagation, or sale is allowed.

Threat to Minnesota

  • It can form dense cover and grow over other plants reducing the amount of native plant species. As vines they can weigh down shrubs and trees and cause them to fall over. Japanese honeysuckle vine can also twist around trees and shrubs and girdle them.
  • The dense cover also makes it more challenging for tree seedlings to survive. Limited tree seedling survival negatively affects wildlife habitat, recreation, the timber industry, and more.
  • In southern states it is known to be a host of insects that are crop pests.
  • One study found evidence for Japanese honeysuckle vine to have allelopathic effects on other plant species. In allelopathy a plant exudes chemicals that have effects on surrounding plants.

What you should do

One way that invasive plant seeds and fragments can spread is in soil. Sometimes plants are planted purposefully. You can prevent the spread of invasive plants.

PlayCleanGo: Stop Invasive Species in Your Tracks

  • REMOVE plants, animals and mud from boots, gear, pets and vehicles.

  • CLEAN your gear before entering and leaving the recreation site.

  • STAY on designated roads and trails.

  • PLANT non-invasive species.

Native substitutes

 

 

Control methods

Mechanical control can be done for small plants by pulling the plant by hand or with equipment such as shovels. For larger plants that have vines extending into trees, do not try to pull down vines in trees as there is danger that you will pull down heavy plants or branches and injure yourself. If you need to remove plants from your property, please review the Minnesota Department of Agriculture's Guide to Removal and Disposal of Noxious Weeds in Minnesota and contact your local County Agricultural Inspector for disposal suggestions in your county.

Herbicide control can be done using glyphosate and triclopyr. These are systemic herbicides that are taken up by plants and move within the plant, which can kill leaves, stems, and roots. Cut the stem close to the ground and then apply herbicide to the cut stump. For basal stem treatment, a method that applies chemical through the bark, low volume spray applications can be made with triclopyr ester (such as Garlon 4, Pathfinder II and similar oil-based products). This application method uses a triclopyr ester product applied directly to the bark of the plant from the root collar up about 12-18 inches. An ultra-low volume spray wand should be used to minimize herbicide use and reduce the potential for non-target injury.

Reporting

Report new occurrences by submitting a report through EDDMapS, emailing Report A Pest, calling Report A Pest (1-888-545-6684), or contacting your local county agricultural inspector.

Resources

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