Invasive Plants to Avoid in Tennessee Landscaping Projects

Tennessee's diverse geography — spanning the Blue Ridge Mountains in the east to the Mississippi Alluvial Plain in the west — creates conditions where invasive plant species spread rapidly and cause measurable ecological and economic damage. This page identifies the invasive species most commonly encountered in Tennessee landscaping projects, explains how each species disrupts native ecosystems, and establishes practical decision frameworks for plant selection. Understanding which species to exclude is as foundational as knowing which Tennessee native plants for landscaping to include.

Definition and scope

An invasive plant, as defined by Executive Order 13112 (1999) and reinforced by the Tennessee Exotic Pest Plant Council (TEPPC), is a non-native species whose introduction causes, or is likely to cause, economic harm, environmental harm, or harm to human health. "Non-native" alone does not qualify a plant as invasive — the critical criterion is documented or projected harm to natural areas, agricultural land, or infrastructure.

Scope and coverage limitations: This page applies specifically to landscaping decisions made within the state of Tennessee, drawing on guidance from the TEPPC, the Tennessee Department of Agriculture (TDA), and the USDA National Invasive Species Information Center (NISIC). It does not address federal quarantine regulations governing interstate plant movement, nor does it cover invasive species management on federally designated lands such as the Cherokee National Forest or Great Smoky Mountains National Park, where separate federal regulatory frameworks apply. Landscaping projects in bordering states (Kentucky, Virginia, North Carolina, Georgia, Alabama, Mississippi, Arkansas, Missouri) fall outside this scope, even if species distributions cross state lines.

How it works

Invasive plants outcompete native vegetation through 4 primary mechanisms:

1. Allelopathy — chemical compounds released into the soil inhibit germination and growth of neighboring plants. Ailanthus altissima (Tree of Heaven) produces ailanthone, a phytotoxic compound identified in research-based literature available through public sources such as USDA Forest Service.
2. Prolific seed production — Ligustrum sinense (Chinese Privet), one of the most problematic invasives in Tennessee, produces thousands of berries per plant per season, dispersed by birds across wide geographic areas.
3. Vegetative regeneration — species such as Lonicera japonica (Japanese Honeysuckle) and Pueraria montana (Kudzu) regrow from root fragments, making mechanical removal alone insufficient.
4. Phenological advantage — invasives including Lonicera maackii (Amur Honeysuckle) leaf out earlier and retain leaves later than native species, capturing photosynthetic opportunity that native understory plants cannot match.

The TEPPC publishes a ranked list categorizing invasive plants into three levels: Category 1 (severe ecological impact, widespread), Category 2 (substantial impact, less widespread), and Category 3 (established but impact still under assessment). Landscaping professionals operating under the Tennessee Department of Agriculture's Plant Industry Division guidance should treat Category 1 and 2 species as non-starters for any new planting.

Understanding these mechanisms is relevant beyond species selection — it also shapes water management and irrigation in Tennessee landscapes, since invasive plants often exploit disturbed or irrigated ground more aggressively than natives.

Common scenarios

Scenario 1: Post-construction site revegetation
Disturbed soils after grading or construction create ideal conditions for invasive colonization. Kudzu (Pueraria montana), classified as a Federal Noxious Weed by the USDA APHIS, can grow up to 1 foot per day under optimal Tennessee summer conditions and will dominate bare ground before specified native ground covers establish. See also Tennessee landscaping after construction for site-specific protocols.

Scenario 2: Woodland edge planting
Ligustrum sinense (Chinese Privet) and Elaeagnus umbellata (Autumn Olive) are frequently mistaken for acceptable shrub selections because of their dense foliage and seasonal interest. Both are TEPPC Category 1 species and form monocultures in woodland margins, eliminating native shrub layers that support pollinator and wildlife habitat — a concern directly relevant to Tennessee landscaping for wildlife habitat.

Scenario 3: Ornamental grass selection
Miscanthus sinensis (Chinese Silvergrass), sold widely in retail nurseries, has naturalized aggressively in Tennessee. It contrasts sharply with native alternatives such as Panicum virgatum (Switchgrass) or Schizachyrium scoparium (Little Bluestem), which provide equivalent visual structure without documented invasive spread.

Scenario 4: Erosion control on slopes
Crown Vetch (Coronilla varia) and Multiflora Rose (Rosa multiflora) are historically sold for erosion control but have both been documented displacing native plant communities. Tennessee landscaping for erosion control details native alternatives — including Juniperus virginiana (Eastern Redcedar) and native grasses — that deliver equivalent slope stabilization.

Decision boundaries

When a plant is listed vs. when it is not: The TEPPC list is the primary decision tool in Tennessee. Any species ranked Category 1 or 2 should be excluded from all project specifications, regardless of client preference. Category 3 species require documented site assessment before inclusion.

Nursery stock and existing installations: Not all nurseries in Tennessee have removed TEPPC-listed species from inventory. The absence of a "Do Not Plant" label at point of sale does not indicate regulatory clearance. Contractors reviewing hiring a landscaping contractor in Tennessee guidance should confirm that species exclusion criteria are written into project scopes.

Contrast — regulated vs. monitored species: Federally listed noxious weeds (e.g., Kudzu, Purple Loosestrife) carry mandatory removal obligations under USDA APHIS authority. State-listed invasives under TEPPC are advisory in most contexts but carry legal implications when installed in proximity to protected natural areas under Tennessee Code Annotated § 70-8-301 et seq., the Tennessee Noxious Weed Law.

For a broader introduction to how plant selection fits into the overall service framework, the how Tennessee landscaping services works conceptual overview provides context. The Tennessee Lawns and Landscape Authority home offers additional guidance resources organized by project type and geography.

References

• Tennessee Exotic Pest Plant Council (TEPPC) — Invasive Plant List
• Tennessee Department of Agriculture — Plant Industry Division
• USDA National Invasive Species Information Center (NISIC)
• USDA APHIS — Federal Noxious Weed List
• USDA Forest Service — Tree of Heaven Research
• Executive Order 13112 — Invasive Species (1999)
• USDA PLANTS Database — Pueraria montana (Kudzu)