It's that time of year. Flowers are blooming, the grass is green, and the sweet scent of honeysuckle wafts in the warm summer air.
Honeysuckle’s fragrance however, may be the only sweet thing about it. According to conservationists in Kansas and Missouri, Asian Bush Honeysuckle is the most visible and environmentally destabilizing invasive species in the metro area.
Larry Rizzo, a natural history biologist at the Missouri Department of Conservation, says that there is a difference between invasive and exotic species, and the two are not necessarily exclusive.
“Not all exotic species are invasive, and not all invasive species are exotic,” he says. “Many exotic species are harmless, don't spread diseases, and aren't harmful. But invasive species are species that displace native species and tend to lead to decline in biological diversity.”
This is exactly what honeysuckle is doing in Kansas City.
“It’s kind of a bully,” says Ryan Armbrust, who is a forest health and conservation officer at the Kansas Forest Service. “Bush Honeysuckle aggressively creates mono cultures of just itself, due to a couple of unfair advantages it has.”
A mono culture occurs when one species dominates the understory and edges of the ground, pushing out other plants and eliminating other species’ chances of survival.
One of the unfair advantages is that Asian Bush Honeysuckle has green leaves from late March to early December, according to Rizzo. Native spring ephemeral wildflowers — which have such evocative names as Dutchman’s Breeches, Jack in the Pulpit, and Spring Beauties — need sunlight in early April to bloom before the trees begin to leaf.
“With the honeysuckle, they can't do it and it literally suffocates them,” Rizzo says.
Wild flowers aren’t the only plants at risk. Valuable trees like oak, maple and hickory, which stabilize the environment and are host to hundreds of species of beneficial life, are in danger of not being able to reproduce because of the heavy shade Asian Bush Honeysuckle casts over the forest floor.
In addition, the honeysuckle creates a problem for soil erosion because the ground beneath it becomes bare and its open branching habit under the canopy exposes songbirds’ nests to predators.
How honeysuckle came to the Kansas City area
Asian Bush Honeysuckle was initially introduced as an ornamental plant in botanical gardens, but became more prevalent when it was pushed as a conservation plant in the 1920s.
“It was initially viewed as a good green plant that grows a lot of places, that spreads quickly, with the idea that it would hold soil. Birds were observed eating its berries, so people figured it was good for the birds,” Armbrust says.
But by the 1950s, it was identified as an aggressive, invasive species — even the birds feeding off its flowers weren’t gaining anything.
“Its berries are junk food for birds, not the type of nutrition migratory birds need,” Armbrust says.
But not all honeysuckle deserves this bad rap.
“We do have quite a few native honeysuckles that are great. One of the differences that you can tell when it’s in flower — a lot of our native honeysuckles are not large and bushy for one thing, but they also have more yellow flowers, striking yellow. Whereas the bush honeysuckle has white flowers, they may age to yellowish a little bit. If it’s a white flower and its pretty big and woody, it’s probably one of the Asian Bush Honeysuckles which are of concern,” Armbrust says.
The bottom line if you are planting a honeysuckle, says Larry Rizzo of the Missouri Department of Conservation, is to know what it is — scientific name necessary.
Efforts to eradicate Asian Bush Honeysuckle
Now that honeysuckle has taken root all over the metro, combating it is nearly impossible.
“Philosophically, is it too late? Are the cows out of the barn, can we unring this bell?” Armbrust asks.
Traditional methods of management, from digging it up to treating it with chemicals can be just as disruptive to the environment as the honeysuckle itself, says Armbrust.
“At this point, it’s a genie out of a bottle. They're here to stay, but we have to draw lines in the sand and protect our most diverse communities,” Rizzo says.
Environmental efforts both in Kansas and Missouri focus on assessing the edges of the threat, reducing the seed base, and controlling future infestations and re-infestations.
“It will be a war of attrition, it's not something we can eradicate rapidly but that doesn't mean eradication efforts are not worthwhile,” Armbrust says.