TN-IPC 2017 List Revision

Overview and Request for Public Comments

Tennessee Invasive Plant Council (TN-IPC) has revised its Invasive Plants of Tennessee list, last updated in 2009. This revision is designed to highlight new plant species that have emerged as potential threats to native plant communities in Tennessee and simplify presentation of the data by eliminating the ranking hierarchy and focusing on species most likely to significantly affect intact native plant communities or hinder their restoration. Therefore, the list does not (re)enumerate all non-native invasive plant species in Tennessee but instead emphasizes species that matter most to those seeking to manage natural areas or restore native plant and animal habitats. In streamlining the list, TN-IPC strives to place a sharp focus on those species that pose the greatest threats to the integrity and function of native plant communities. For these reasons, the list is organized into two categories, Established Threat and Emerging Threat.

1. Established Threat — Many species in this category are archetypal invasive weeds known by every land manager, but all are widely established across Tennessee. All taxa assigned to this category have been reported from more than 10 counties. These taxa cannot be eradicated on a landscape scale using methods currently available, but officially designating the plants as invasive may serve to educate the general public and give land managers support to eradicate the species where appropriate (i.e. high quality natural areas, in tandem with rare species management, part of public engagement/citizen science projects, etc.). In addition, designating the species as a threat may push industry and state/federal agencies toward less invasive alternatives in landscaping and revegetation, thereby helping to avoid the next serious exotic plant escape.

2. Emerging Threat — Species in this category have been previously reported from less than 10 counties in Tennessee, but are known to invade and disrupt natural plant communities in adjacent states. Theoretically, the early detection/rapid response model could be used to eliminate infestations or reduce the spread of these species in Tennessee. In addition, the act of listing these plants, many of which are relatively obscure in Tennessee, will help the land managers and the general public to recognize these species in the field.

TN-IPC 2017 List Revision Sources: Please click this link for a PDF containing sources of information used in the compilation of the revised list.

 

Established Threats

Emerging Threats

Public Comments

Comment 1

Is it not possible to ban or at least strongly discourage sales of these invasive plants in TN? Maybe at least require a warning sign where they are sold? It’s crazy to me how some of them are sold openly at common places like Home Depot and Lowes! I’ve actually bought some before not knowing and when I returned them and spoke with them about it at my Home Depot they said they weren’t aware and they did not control which plants their supplier gave them… Maybe an education campaign to these stores would be helpful!
-Rachel Goulet

TN-IPC Response

The state of Tennessee has chosen to regulate the sale of a small subset of invasive plant species. The Tennessee Department of Agriculture Pest Plant List 0080-06-24-.02 prohibits the propagation and sale of thirteen plant species including the common invasive plants bush honeysuckle and Chinese privet.

One northern state recently instituted an informational tag requirement on commercially available invasive species that are not currently banned from sale. This approach warrants research to determine its feasibility here. TN-IPC has targeted its education outreach to public consumers through our brochures “Tennessee’s Native Plant Alternatives to Exotic Invasives” and “Landscaping with Native Plants.” Because plants sold at big box stores are decided on a regional basis, the national and regional organizations NAIPC and SE-EPPC are best equipped to lead an education campaign for these large retailers. TN-IPC will encourage this.

Comment 2

Chinese parasol tree (Firmiana simplex) is well-established in north Knoxville (Knox County) and should be added as an emerging threat due to the rapidity with which I see it multiplying. I have witnessed stakes cut from saplings of this tree rooting and sprouting after being stuck into the ground for tomato supports. I suspect it would root from a branch node, if a cut bole were placed on the ground. Not sure what is happening with the seeds. Not seen it in bloom yet where it is established, but it is a very aggressive root sprouter, even in shade. I suspect this particular population came from a tree that was planted as an ornamental. This plant should not be sold!!!!! Just Google “Chinese parasol tree for sale” and freak yourself out on the returns.

I expect porcelainberry [Ampelopsis brevipedunculata] to make its way out into the more rural and protected areas rather quickly. The birds spread them copiously and young plants are sprouting vigorously this year (2017) in north Knoxville, likely due to all the rain we’ve had this year. I see new vines quite often.

This is a first pass on the list. I’ll give the list more thought as I have time.                                                        -Lisa Huff

TN-IPC Response

After visiting the infestation site in North Knoxville and noting the ability for the species to be invasive in adjacent states to the south, TN-IPC agrees Firmiana simplex could pose a threat to Tennessee plant communities in the future and will add the species as an Emerging Threat. Hopefully, the ongoing eradication efforts in North Knoxville will be successful and keep the species from spreading further.

Ampelopsis brevipedunculata is listed as an Emerging Threat.

Comment 3

When I worked in the Cumberland Plateau region of Tennessee, I dealt with beefsteak plant (Perilla frutescens) as an emerging threat. Never saw it where I worked until 2013 or 2014 and then all of a sudden it was popping up frequently. At the time, it was mainly invading roadsides, floodplains, and trail-edges. It was tough to keep pace with the spread of the plant but early detection and rapid response helped make control efforts possible. EDDMapS shows the distribution of beefsteak plant to be statewide so its status should at least be listed as an emerging threat.

Big box stores have been selling this plant and other cultivars for some time now. As long as that continues, I would imagine the threat of its invasion to become more problematic.
-Justin Coffey

TN-IPC Response

Beefsteak plant is considered a threat in Kentucky and Virginia and has been previously documented from many counties in Tennessee. TN-IPC agrees this species can be invasive. Due to its broad distribution across the state, the plant will be added as an Established Threat.

Comment 4

I agree that Perilla frutescens seems to be an emerging problem. I have seen it here in Hamilton County.
Glechoma hederacea – creeping charlie is also very common here.
Cynodon dactylon – [Bermuda grass] Everywhere. Almost seems like people are encouraging this stuff…….
Conium maculatum poison hemlock – is also a very common weed here in Hamilton County.
-Lyn

TN-IPC Response

TN-IPC agrees Conium maculatum, Cynodon dactylon, and Glechoma hederacea are weedy plants that grow in disturbed habitats in Tennessee. However, the objective of the list is to focus on species that “pose a significant threat to native plant communities.” In our view, these species do not usually invade intact native plant habitats and, therefore, do not warrant inclusion on the list. See comments on Perilla frutescens above.