This is high season for wildflower hikes along the Kentucky River Palisades, where plants found few other places in the region put on a colorful show.
It also is the time when keepers of these natural areas take a break from months of battling invaders determined to choke out these delicate native species.
The Palisades have suffered widespread damage in recent years from invasive plants including garlic mustard, wintercreeper euonymus, Chinese privet and, most vicious of all, Asian bush honeysuckle.
"I tell people that honeysuckle is why this tree-hugging environmentalist became a mass murderer," said Clare Sipple, who manages the Lower Howard's Creek Nature and Heritage Preserve in Clark County. "No telling how much of that stuff I've killed."
Sipple said honeysuckle is a big problem in the 338-acre preserve.
"We have a dedicated group of volunteers who work nine months a year clearing honeysuckle, and they have made a huge difference," she said. "Once you get the invasives out, the natives start coming back."
Fayette County's Raven Run and Floracliff nature preserves wage similar efforts.
"We work on it from August to February full-time at least two or three days a week," said Beverly James, the manager of Floracliff. "It's not something you can clear once and walk away from. It's a continual battle."
When some plants and animals are transplanted from one continent to another, they can go wild because they have no natural predators. Among the most famous is kudzu, the fast-growing Asian vine that is swallowing the South.
Asian bush honeysuckle was brought here from China as an ornamental plant in the late 1800s, but it has been a growing threat in this region since the 1970s, said Julian Campbell, a botanist and authority on Kentucky native plants.
Ironically, bush honeysuckle is now an endangered species in Japan, where it was native. But it is taking over forests in Kentucky, Ohio and Indiana.
Honeysuckle is mainly spread by birds, who eat its red berries and then scatter the seeds across the landscape in their droppings. Invasives also have been brought into the Palisades region each time a new road has been built or a building put up there.
As we hiked through underbrush along Cane Run Creek several years ago, looking for stands of native cane, Campbell pointed out how the ground beneath big stands of honeysuckle was bare.
"There must be some kind of underground chemical warfare going on," he said. "Nothing grows around it."
The most common way people attack honeysuckle is to chop or saw it off just above ground level and spray the exposed wood with a strong solution of an herbicide such as glyphosate, commonly known by the brand name Roundup.
That kills the plant, but it won't stop another honeysuckle from sprouting up next to it. It's a never-ending task.
Campbell has pondered ways to effectively battle honeysuckle, especially in the Bluegrass region's most sensitive environmental areas. "We know how to kill it," he said. "What we don't have is a method. It's a human organization problem."
He has been thinking about ways to organize small groups to fight it on a continual basis. He also thinks more research is needed on permitting cattle, sheep or goats to browse honeysuckle and wintercreeper in some wooded areas during fall and winter, as deer do.
"It's less in the deepest woods, which is a glimmer of hope," he said of honeysuckle. "Shade and browsing seem to reduce it."
Campbell has begun his own small effort as part of hikes he leads at least monthly in Central Kentucky's natural areas. Participants pay $10, which is donated to regional conservation organizations, or they can spend some time that day with him, cutting and spraying honeysuckle. For more information, email firstname.lastname@example.org.
Despite the invasion, there are plenty of beautiful wildflowers to see this time of year, including rare snow trillium, Dutchman's breeches, bloodroot and native phlox.