The Kentucky Invasive Plant Council (KY-IPC) hosted their annual conference on November 2, 2023 at Kentucky State University’s Research and Demonstration Farm in Frankfort, KY. This was the first time KY-IPC hosted an in-person conference since the event started virtually in 2021, with over 150 people in attendance. The conference was a great opportunity for land management professionals, private landowners, natural area volunteers/stewards, researchers, and nonprofits from across Kentucky to get together to discuss the latest news and emerging threats here in the state and to earn continuing education units (CEU’s) for their pesticide license.
2023 KY-IPC Conference at KSU’s Research & Demonstration Farm in Frankfort, KY
This year’s conference was split into indoor presentations and outdoor demonstrations. Some of the topics discussed included managing invasives when installing native grasslands, biological controls of invasive plants (garlic mustard aphid and honeysuckle leaf blight), invasive species to watch for (spotted lanternfly, Japanese chaff flower, amur cork tree, and overlooked invasive plants along fire breaks), and a case study of aerial spraying of bush honeysuckle at Clay WMA. Demonstrations included using drones for invasive plant monitoring and management, research plots of invasive plant management at KSU Farm, and invasive plant management with goats.
Another highlight of the annual event was to recognize people and places that are doing great work towards invasive species eradication in the state. KY-IPC solicited nominations for three categories to recognize a professional land manager, a nonprofessional individual, and a natural area or organization.
Ryan Fortenberry, OKNP Cumberland Plateau Land Manager
The 2023 KY-IPC award recognizing a professional land management practitioner in invasive species management went to Ryan Fortenberry, the Cumberland Plateau Land Manager for Office of Kentucky Nature Preserves (OKNP). Ryan is an excellent steward of the nature preserves under his watch. He is charged with protecting many sensitive sites with high quality natural communities and rare species, which he maintains through his vigilance of looking for and eradicating invasive species before they become a problem. He also has multiple sites where the invasives were already a problem, and he has worked to eradicate those populations through his hard work and dedication.
Terri Koontz, Kentucky natural areas steward and volunteer
The 2023 KY-IPC award recognizing a nonprofessional individual went to Terri Koontz, a volunteer at several natural areas in Kentucky. When she learns of a new emerging invasive plant, she is not satisfied simply to know it exists; she goes out of her way to learn all she can about it, including why it is in invasive, how to correctly identify it, and what she can do to manage it. Terri recently learned to recognize Japanese chaff flower and took it upon herself to remove a large population behind the Gladie Visitor Center at the Red River Gorge. By sharing her passion, knowledge, and willingness to get down on the ground and work with friends and other volunteers, Terri stewards Kentucky natural areas wherever she goes.
Jimmy Woods, KDFWR Wildlife Biologist, accepting award on behalf of Clay WMA
The 2023 KY-IPC award recognizing a natural area or organization dedicated to invasive species eradication went to Kentucky Division of Fish and Wildlife Resources’s (KDFWR) Clay Wildlife Management Area. Clay WMA is one of the most intensively managed areas for wildlife habitat in Kentucky through invasive species eradication and prescribed fire. The current land manager, Jimmy Woods, wrote a three-year management plan to treat the entire WMA for bush honeysuckle, which included a 2022 aerial herbicide spraying of large tracts of the forest in collaboration with UK researchers to evaluate the effectiveness of the treatment. Clay WMA has also hosted several educational field days for various groups to view and learn about large-scale management operations of invasive species.
The final highlight of KY-IPC’s 2023 annual conference was the announcement of this year’s winner of funding for a natural area boot brush station, which was awarded to Kentucky Natural Land Trust for their Blanton West Preserve near Blanton Forest State Nature Preserve in Harlan County. A boot brush station will help fight the spread of invasive species and signage will educate the public about invasive species.
Join us April 2nd at 11am EDT as we pull winter-creeper from populations of running buffalo clover at Ashland, The Henry Clay Estate in Lexington following the iNaturalist tutorial hike. To learn more about running buffalo clover, click here. You do not need to partake in the iNaturalist tutorial hike to help pull winter creeper, but you are welcome to! Bring a knee pad and gardening gloves if you have them. We will meet next to the Gingko Cafe. If you wish to join in, please email Heidi Braunreiter, heidi.braunreiter@ky.gov.
By Heather Doolin, Office of Kentucky Nature Preserves
Heavenly bamboo (Nandina domestica), also commonly called sacred bamboo, is an evergreen shrub, vaguely resembling bamboo. Heavenly bamboo began its journey in North America as an ornamental plant, escaping cultivation and invading forests of ten southern states, Kentucky being included in those affected.
By Deborah White, Kentucky Native Plant Society Board
By the end of winter, we are looking for any hope of spring, any bright color in the landscape we can find. When you see a pretty yellow flower in late winter, check to see if it is lesser celandine (Ficariaverna) before you get excited.
Description
Ficaria verna: Common License
The leaves of this invasive plant emerge in winter, and they cover the ground quickly, outcompeting many native plants. This pest plant has a single yellow flower at the end of a stem. It is closely related to buttercups (its former name is Ranunculusficaria, and sometimes it is called fig buttercup) and, like buttercups, the flower has many stamens. There are seven to thirteen flower petals. The leaves are medium to dark green, generally heart-shaped and not lobed with wavy edges that have smooth or rounded teeth. Also, the small bulbils at the base of the plant will help identify it (see also the control section as these bulbils allow this weed to spread).
Habitat
Lesser celandine grows in riparian areas like stream banks and adjacent flat moist areas, shady woods and even lawns. Lesser celandine is found in the eastern United States, west from Texas and Missouri, as well as Washington and Oregon on the west coast.
Lesser celandine covered these shaded woods at UK Arboretum in 2019. Photo by Emily Ellingson.
How it Got Here
Lesser celandine is native to Europe, Asia and Africa. Introduced to the United States for horticultural use as a border plant, this weedy invasive is, unfortunately, still being sold. It easily escapes from gardens to nearby forests. The fingerlike bulbils and fruit can be spread by flooding, or any movement from one habitat to another, even mowing.
Lesser celandine in the United State; blue states show its presence. Map by NRCS.
Ecological Impacts
Lesser celandine can quickly form a blanket across the ground in natural areas. It crowds out native plants and depresses their reproduction. Like other invasive weeds, the elements that control these plants in their native range, whether fungus, animals or other biological controls, are absent, leaving this plant free to increase, unchallenged.
How to Control
Small infestations may be removed by pulling the plants by hand, but all plant parts must be removed to be effective. The roots and bulbils easily fall from the plants and then establish new plants!
It is also possible that covering the plants with black plastic to solarize, or heat up the soil can help kill the vegetative structures and root systems of the plants. This would be appropriate where lesser celandine is abundant.
Studies show spraying with herbicide is effective, especially if applied before other plants have emerged. Glyphosate has been used to control lesser celandine but be aware that it is not appropriate for use near aquatic habitats. A 2.5% solution may be applied when it is at least 50 degrees Fahrenheit–being extra careful to spray only lesser celandine because the herbicide will affect any plant it contacts. It may take two or even three applications and future monitoring to eliminate the plants. You will be helping our natural flora by battling this yellow invader!
References
Aulakh, Dr. Jatinder S. Lesser Celandine (Ficaria verna Huds.) Identification and Management. Connecticut Agricultural Experiment Station.
At the end of winter we are looking for any hope of spring, any bright color in the landscape we can find. When you see a pretty yellow flower in late winter, check whether it is lesser celandine (Ficariaverna) before you get excited.
Deborah has been a botanist for the Kentucky Office of Nature Preserves and Florida state plant conservation programs.
Japanese Stiltgrass (Microstegium vimineum), often called Stiltgrass or most commonly Microstegium, is a shade tolerant grass in the Poaceae/Grass plant family. This is the second most biodiverse plant family in Kentucky right behind Asteraceae/Sunflower family. Given the massive number of species in the family and the distinctness between members in the family, recognizing Microstegium can be tricky but I hope to help so that native plant lovers can start to remove this species from their landscape!
Description
It is likely if you have hiked along a creek in a disturbed area or walked along a road, you have probably come across Japanese Stiltgrass and thought nothing of it. However, this should be of great concern to landowners/land managers/native plant enthusiast. Once you can competently identify the next patch of Microstegium you come across, you can help eradicate it from the area.
DISTINCT FEATURES
By far, the most distinctive feature for Microstegium that I use in field identification is the faint silver line running down the middle vein of the leaf. This characteristic is not as prominent and distinctive among any other native grasses in Kentucky.
Silver line on leaf of Microstegium (picture taken by Nick Koenig).
APPEARANCE
Japanese Stiltgrass is a “weak-stemmed annual, branching, decumbent [running along the ground then rising up], rooting at the lower nodes [points where leaves or stems come out].” (Weakley 2015).
Picture of a few Microstegium shoots prior to flowering and seeding (picture provided by Jeff Nelson).
LEAVES
As described in the Flora of the Southeast (Weakley), the leaves are ovate-lanceolate (meaning oval and much longer than wide, roughly 2.5-7 times longer than wide ), 2-10 cm long tapering at the base.
HABITAT
Microstegium can most likely be found in “disturbed areas, colonizing moist, rich soil, especially in floodplains” such as along a creek bank where it is often found (Weakley 2015). Due to the Japanese Stiltgrass’s ability of being shade-tolerant, the species can make deep incursions in a forested area.
Amur honeysuckle (Lonicera maackii) is the most widespread and arguably the most invasive of the nonnative invasive honeysuckle shrubs in Kentucky. Jeff Nelson’s article on Amur honeysuckle provides a general overview of the species. This article provides some details as to why this species is so invasive and why is an ecologically undesirable species.
Amur honeysuckle, native to central and northeastern China, Japan (rare), Korea, and far eastern Russia, occurs as an understory shrub in open hardwood and mixed hardwood-conifer forest consisting of oaks, elms and other hardwoods and fir, spruce and hemlock. It is also known from and more common in riparian and scrub communities (Luken and Thieret 1996). It grows as scattered individual shrubs or small clumps, not unlike viburnums do in Kentucky. Large, dense stands do not typically occur, but in open, riparian areas it can be weedy. In its native range, individuals typically do not exceed 4 inches diameter and 20 feet tall (Yang et al. 2011). In Kentucky, the species is often an understory shrub in open forest, but forms dense thickets at forest edge, along fence rows and in open areas. It grows larger here as well, to 6 inches diameter and 30 feet tall (personal observation).
Large Amur honeysuckle, two stems 5 inches or greater in diameter. 29 April 2020. Photo by David Taylor
This shrub leaves out early in spring, often breaking bud in mid-March, long before native trees and shrubs. By mid-April of most years, leaves are fully expanded, and the shrubs are actively growing. In the fall, Amur honeysuckle typically senesces (leaves turn yellow and drop) in late October to mid-November, and sometimes not until early December. Native trees and shrubs typically break bud late March to mid-April and do not fully expand until early May. In eastern Kentucky, they are actively dropping their leaves by mid- to late October in most years. The extra 5-8 weeks of photosynthetic activity in the honeysuckle allows it to store additional energy giving it an edge over native species (McEwan et al. 2009). It is also somewhat tolerant of late freezes. Both promote its invasive nature.
Tall Amur honeysuckle, approximately 27 feet tall. 29 April 2020. Photo by David Taylor
While Amur honeysuckle grows better in full sun (Luken 1995), it is known to survive in 1 percent of full sunlight in the heavy shade of trees (Luken et al. 1997a). The native spring flowering spice bush (Lindera benzoin) by comparison, requires about 25 % of full sun to survive (Luken et al. 1997a). Forest grown Amur honeysuckle under heavy shade tends to produce few stems which grow upward toward light specks. They tend not to have much branching, nor do they attain much diameter. In the open, individual shrubs produce numerous stems and branching is extensive. Maximum diameters are obtained in the open (Luken et al 1995a). Overtopped Amur honeysuckle shrubs respond with the production of long, upright stems that seek light. Honeysuckle in open forest may branch extensively and produce heavy shade.
In any list of the top five invasive plant threats to Kentucky’s native plant communities, bush honeysuckle would appear in all of them. There are three species of bush honeysuckle commonly found in Kentucky: Amur (Lonicera maackii), Morrow’s (L. morrowii), and Tartarian (L. tatarica). Another two, Standish’s (L. standishii) and Fragrant (L. fragrantissima), are less common. All are members of the Caprifoliaceae (Honeysuckle) family. All of them are similar in appearance and effect. Because of the similarities and because it is the most widespread of the bush honeysuckles, the rest of this article will concentrate on Amur honeysuckle. There are slight differences in appearance between Amur honeysuckle and the other bush honeysuckles, but in general they are similar enough to easily recognize.
Description
Most of us have seen invasive Lonicera while hiking or even around town. They’re everywhere. Knowing how to identify them is the first step to removing them.
Appearance
Lonicera maackii is a woody perennial shrub that, at maturity, is typically 6’-20’ tall, but occasionally taller. The shrubs are upright and deciduous. Although deciduous, in Kentucky the bush honeysuckles retain their leaves longer in the fall than native shrubs and leaf out earlier in the spring. The pith of mature stems is hollow and white or tan.
Leaves
Leaves are opposite, ovate with a tapered tip, lightly pubescent, and up to 3½ in. long.
Flowers
Flowers are paired, tubular, white to pinkish, fading to yellow, less than 1 in. long, borne from leaf axils, five petals, upper 4 fused.
Fruits
Fruit
Fruits are red to orange-red berries produced in late summer and persist through the winter. This shrub can bear fruit when it is as young as 3 to 5 years old.
Habitat
Amur
honeysuckle is one of the most common and invasive bush honeysuckles
found in Kentucky. It occurs in most states in the eastern U.S.
except for Minnesota, Maine and Florida and has been reported to be
invasive in many. It is adaptable to a range of conditions from sun
to deep shade and wet to dry. It occurs in disturbed habitats
including forest edges, forest interiors, floodplains, old fields,
pastures, and roadsides. Disturbance increases the likelihood of
invasion. Amur honeysuckle grows especially well on calcareous soils.
It spreads by fruits that are abundant and highly attractive to birds that consume them and defecate the seeds in new locations. Vegetative sprouting aids in the local spread and persistence. It does not generally root sprout.
Where Found in KY
The
bush honeysuckles are found across Kentucky, in any just about any
suitable habitat.
How it Got Here
NE
China, Japan, Korea, and Russian Far East
Amur honeysuckle was imported as an ornamental into New York in 1898 through the New York Botanical Garden. It has been widely planted for wildlife cover and soil erosion control but long ago escaped from plantings and began reproducing on its own and spreading into natural areas. It was originally planted in the U.S. as an ornamental shrub, but it quickly escaped gardens and naturalized throughout much of the eastern U.S. to the Great Plains into a variety of sites including roadsides and railroads, woodland borders, some forests, fields, unused or disturbed lands and yard edges. Once spread into the wild, it can form dense, shrubby, understory colonies that eliminate native woody and herbaceous plants. Amur honeysuckle flowers late April to June, and the white and yellowish flowers produce red berries in the fall that may contain more than 1 million seeds on mature (25-year-old), 20-foot tall plants. The seeds are consumed and spread by some species of songbirds generally after other more nutritious native foods are gone. As with many invasive species, bush honeysuckle can grow and thrive over a wide range of habitats. In Kentucky, all shrub honeysuckles are exotic and invasive.
Ecological
Impacts
Amur honeysuckle impedes reforestation of cut or disturbed areas and prevents reestablishment of native plants. It leaves out earlier than most natives and form dense thickets too shady for most native species. Additionally, researchers in the Midwest found increased nest predation of robins using Amur honeysuckle as a result of plant structure, which facilitates access to nests by predators such as snakes. While the carbohydrate-rich fruits of exotic honeysuckles provide some nutrition for birds and rodents in winter, they do not compare to the lipid-rich fruits of native species that provide greater energy to sustain migrating birds. Few insects feed on the plant, but birds and mammals spread the fruits. It may have allelopathic effects on neighboring plant species.
How to Control
There are several methods for controlling–removing–invasive bush honeysuckle. They all take tenacity and a bit of effort.
Manual/Mechanical
Young plants can be pulled by hand. Larger plants either can be pulled using a weed lever-type tool or cutting repeatedly for a few years.
Grazing
Goats are particularly fond of this this plant and will rapidly consume young plants and any they can climb into. Cutting larger plants and allowing goats to eat the sprouts can be effective, but could take several years depending on what root reserves the plants have.
Fire
Fire will kill seedlings. Larger plants may be top killed, but mostly likely will sprout from the base. The sprouts must be treated as well.
Biological Control
No biological controls are currently available for this plant. However, the honeysuckle leaf blight fungus (Insolibasidium deformans) has been found in both northern and central Kentucky. It has been observed severely injuring and killing open grown populations of Amur honeysuckle.
Herbicides
Appropriate herbicides, when applied correctly, are known to effectively control bush honeysuckle through cut stem, foliar, and bark applications. Contact your local Extension Office, or Natural Resources Conservation Service office or Kentucky Department of Fish and Wildlife private lands biologist for recommendations concerning herbicide choice, application rate and application method that best suit your conditions and needs.
Native Alternatives
Lonicera simpervirens
Whether you were raised in Kentucky or you’re an implant, you’ve probably enjoyed the luscious fragrance of honeysuckle as the sun begins to set. It isn’t quite jasmine; not quite gardenia; it’s unique, powerful, and intoxicating. It’s easy to understand why homeowners planted the invasive Loniceras. Where alternatives are concerned, there’s good and bad news. The good news is that we have native Lonicera. The bad news is, they are pollinated by bees and hummingbirds, so the scent is weak. In comparison, the invasive is pollinated by moths—hence the strong evening scent. What the natives lack in fragrance, they make up for in color (to attract the bees and hummingbirds).
Across North America, there are over a dozen native Lonicera species. In Kentucky, we have one to consider: Lonicera sempervirens L., trumpet or coral honeysuckle. It prefers moist soil and full sun, but tolerates shade, although, in the shade, it will produce blooms for a shorter period of time.
Lonicera simpervirens
Lonicera sempervirens is one of the longest-blooming natives available to us here in Kentucky. It’s brilliant red trumpet-shaped flowers spring into life as early as late March and persist into fall, even early winter. Its leaves often persist throughout the cold, giving a bit of winter interest. The base is woody and gnarly (interesting to look at) but the vigorous upper vines are gentle and easily coiffed if necessary. You can train it to look like a bush if you prefer.
Unfortunately, Lonicera sempervirens won’t gift you with a glorious fragrance. If that’s what you’re after, consider Wisteria frutescens (L.) Poir., Kentucky wisteria. Similar to Lonicera, you’ll get the most blooms in full sun, but it will tolerate shade. It’ll grow in the same type of moist soil as well. It’s purple blooms are larger and showier, and it’ll grow a bit larger than Lonicera, but the native species isn’t as harmful to structures as the invasive Wisteria floribunda and Wisteria sinensis. Wisteria is stronger and woodier than Lonicera so it will require a stronger support, such as a strong arbor. (Resist growing it along a fence or up the side of your house because it’s difficult to remove.) It’s also more assertive than the native Lonicera, so it might require a bit more care to keep it under control.
There are several other species of Lonicera listed as native to Kentucky by the USDA plants database, but they’re rare or endangered. It’s unlikely you will find one in a reputable nursery.
