Find and Eliminate Asian Bush Honeysuckle in Your Woods

Above: Purdue's Lenny Farlee standing in front of Asian bush honeysuckle with bright red berries.

Take a walk in your woods, a local park, or along a walking trail. As most deciduous trees have lost, or are losing, their leaves, you might notice a shrubby plant in the understory that still has green leaves and reddish berries. This could be one of the Asian bush honeysuckles, an invasive plant.

Asian bush honeysuckle is an umbrella term for four problematic shrub honeysuckles in Indiana: Amur, Tatarian, Morrow’s, and Bell’s honeysuckle. All 4 are included in Indiana’s Terrestrial Plant Rule (see https://www.in.gov/dnr/rules-and-regulations/invasive-species/terrestrial-invasive-species-plants).

In fact, one competitive advantage Asian bush honeysuckles have is that they green up early in the spring and stay green later in the fall.

According to Indiana Plant Species Assessment Working Group (IPSAWG), “Asian bush honeysuckles grow so densely they shade out everything on the forest floor, often leaving nothing but bare soil. This means a great reduction in the food and cover available for birds and other animals. Serious infestations can inhibit tree regeneration, essentially stopping forest succession.”

IPSAWG reported that these invasive honeysuckles were introduced from Eurasia as ornamentals, for wildlife cover and for soil erosion control. “However, their aggressive domination of native communities makes them a bad choice for these purposes,” said IPSAWG. “In Indiana they are particularly invasive in central and northern parts of the state, but are starting to move into the southern portion.”

“Asian bush honeysuckle is very tolerant of shade and has seeds that are spread by birds,” said Lenny Farlee, Sustaining Hardwood Extension Specialist at Purdue University. “So, it’s very easy for it to invade the forest environment.”

“Asian bush honeysuckle can be recognized with opposite leaf arrangement and grey, brown, or tan stems,” said Farlee. “If the Asian bush honeysuckle twigs are sliced in half, we can see that they have a hollow pith and a brown fuzziness on the inside of that void.” He added that we’ll find that most of our native shrubs have a solid pith on the inside of the stems.

Several species and hybrids of Asian bush honeysuckle can be found in the eastern United States. “They do vary some in terms of leaf color, texture, and shape, and also some variations in the color of the flowers,” he said. “However, they are consistent in terms of having opposite leaf arrangement, and also the hollow stems.”

“Asian bush honeysuckle is capable of growing in many different types of soils and site situations,” said Farlee. This adaptability is another competitive advantage of these plants.

“In late summer and fall, Asian bush honeysuckle can have orange to bright red fruit lined along the stem,” said Farlee. “This fruit is very juicy and watery.” The birds will eat them, but they are not a great food value to the birds.

“In central and northern parts of the eastern United States, Asian bush honeysuckle often holds its leaves into the fall well past when most of our deciduous hardwood trees have dropped theirs,” said Farlee. “This provides an opportunity for scouting for Asian bush honeysuckle, and also an opportunity to evaluate how heavy an infestation may be.”

Woodland owners striving for good forest health may spend a great deal of time and money controlling invasive species, and the Asian bush honeysuckles are often part of that control strategy. The more we can all do to help control these plants, the better.

For more information, access IPSAWG’s fact sheet on Asian bush honeysuckle, including control methods, at: https://www.in.gov/dnr/files/Bush_Honeysuckle.pdf. Find a video narrated by Farlee on Asian bush honeysuckle at: https://www.youtube.com/watch?v=uYoRgE7xTQo.