A Landowner's Guide to Invasive Species in the Southeast

The Invasive Species Crisis in Southeastern Forests

Invasive plant species are transforming southeastern forests at an alarming rate. Across the Coastal Plain, Piedmont, and Sandhills — from Central Florida through the Carolinas — non-native plants are displacing the native vegetation that southeastern wildlife has depended on for millennia.

The numbers are staggering. The Southeast hosts over 1,400 documented non-native plant species, of which more than 300 are classified as invasive — meaning they spread aggressively and cause ecological or economic harm. The USDA estimates that invasive species cause over $120 billion in economic damage annually across the United States, and the Southeast bears a disproportionate share due to its mild climate, long growing seasons, and extensive forest and agricultural land.

For private landowners, invasive species are not an abstract problem. They reduce timber growth, degrade wildlife habitat, decrease property values, and make land less enjoyable and functional. A property overrun with Chinese privet, Chinese tallow, or cogongrass is worth less, supports less wildlife, and costs more to manage than one dominated by native vegetation.

The good news is that invasive species can be managed — and in many cases eliminated — with the right combination of mechanical treatment, herbicide application, and prescribed fire. This guide covers the most problematic invasive species in southeastern forests, how to identify them, what damage they cause, and how to fight back.

The Most Damaging Invasive Species

Chinese Privet (Ligustrum sinense)

Identification: Chinese privet is an evergreen to semi-evergreen shrub or small tree that grows up to 30 feet tall. It has opposite leaves (1–2 inches long), clusters of small white flowers in spring, and abundant dark purple berries in fall and winter. Dense thickets of privet can form an impenetrable understory wall.

Origin and spread: Native to China, introduced to the United States in the 1850s as an ornamental hedge plant. It has since invaded millions of acres across the Southeast, particularly in bottomland forests, riparian areas, and fire-suppressed uplands.

Ecological impact: Chinese privet is arguably the single most damaging invasive plant in southeastern forests. It:

• Forms dense, monoculture thickets that shade out all native groundcover
• Displaces native shrubs and understory trees
• Reduces wildlife food and habitat quality (privet berries have minimal nutritional value compared to native fruits)
• Alters soil chemistry and nutrient cycling
• Persists in heavy shade, making it almost impossible to outcompete

Management: Privet is difficult to control because it resprouts aggressively from the root system after cutting or mulching. Effective management requires:

1. Mechanical removal: Forestry mulching to remove the above-ground biomass
2. Cut-stump herbicide: Application of triclopyr (Garlon) or glyphosate to freshly cut stumps within 24 hours of cutting. This is the most critical step — without herbicide, privet will resprout within weeks.
3. Follow-up treatment: Monitor for resprouts and seedlings over the following 2–3 years. Foliar spray or basal bark treatment of resprouts is usually necessary.

Chinese Tallow (Triadica sebifera)

Identification: Chinese tallow is a deciduous tree that grows up to 60 feet tall. It has heart-shaped or diamond-shaped leaves (2–3 inches long) that turn brilliant red, orange, and yellow in fall — making it attractive but dangerous. White, waxy seeds in clusters are visible in fall and winter.

Origin and spread: Native to China and Japan, introduced to the U.S. in the 1700s for its seed oil. Benjamin Franklin reportedly promoted its cultivation. It has since invaded millions of acres across the Gulf Coast and lower Coastal Plain, from Texas to the Carolinas. Central Florida is on the front lines of Chinese tallow invasion.

Ecological impact: Chinese tallow is one of the fastest-growing trees in the Southeast, capable of reaching 15 feet in height within 3 years. It:

• Rapidly colonizes disturbed areas, old fields, and forest edges
• Produces enormous quantities of seed dispersed by birds
• Tolerates a wide range of soil conditions, from dry uplands to flooded wetlands
• Forms dense, single-species stands that exclude native vegetation
• Alters soil chemistry through allelopathic leaf litter

Management:

1. Forestry mulching: Effective for removing dense tallow stands
2. Cut-stump herbicide: Triclopyr applied to fresh-cut stumps. Essential to prevent resprouting.
3. Basal bark treatment: For scattered individual trees, applying herbicide (triclopyr in oil carrier) to the bark around the base of the tree kills the tree without cutting.
4. Hack-and-squirt: For larger trees in sensitive areas, herbicide is applied into cuts made in the bark.
5. Follow-up: Chinese tallow seed can remain viable in the soil for several years, so monitoring for new seedlings is essential for 3–5 years after treatment.

Cogongrass (Imperata cylindrica)

Identification: Cogongrass is a perennial grass that grows 2–4 feet tall in dense, circular patches. It has light green leaves with an off-center white midrib (a key identifying feature). In spring, it produces silvery-white, fluffy seed heads that are distinctive and easy to recognize.

Origin and spread: Native to Southeast Asia, cogongrass was accidentally introduced to Alabama in 1912 in packing material, and was later intentionally planted for erosion control and forage (it proved to be useless for both). It has since spread across the Gulf Coast states and into Central Florida, and is moving northward.

Ecological impact: The Federal Interagency Committee for the Management of Noxious and Exotic Weeds has called cogongrass the worst invasive weed in the world. In the Southeast, it:

• Forms dense, monotypic stands that exclude all native vegetation
• Has an aggressive rhizome system that makes it extremely difficult to eradicate
• Burns at extremely high temperatures (up to 1,000 degrees F), creating wildfires intense enough to kill mature pine trees
• Is unpalatable to wildlife — deer, cattle, and other herbivores refuse to eat it
• Reduces property values and can restrict land use

Management: Cogongrass is the most difficult invasive species to control in the Southeast. Effective management requires:

1. Herbicide application: Glyphosate (Roundup/Accord) or imazapyr (Arsenal) applied as foliar spray to actively growing cogongrass. Multiple applications over 2–3 years are typically required.
2. No mulching alone: Forestry mulching without herbicide follow-up actually worsens cogongrass infestations by fragmenting and spreading rhizomes.
3. No burning without herbicide: Burning cogongrass without prior herbicide treatment stimulates more aggressive growth.
4. Monitoring: Cogongrass can resprout from small rhizome fragments. Monitoring for 5+ years after treatment is essential.
5. Quarantine: Avoid moving soil or equipment from infested areas to clean areas without thorough decontamination.

Brazilian Pepper (Schinus terebinthifolia)

Identification: Brazilian pepper is an evergreen shrub or small tree (up to 30 feet tall) with compound leaves that have a distinctive peppery smell when crushed. Clusters of bright red berries appear in winter, giving it the common name “Florida holly.”

Origin and spread: Native to Brazil, Paraguay, and Argentina. Introduced to Florida in the 1840s as an ornamental. It now covers over 700,000 acres in Florida alone and is expanding northward. It is a Category I invasive in Florida, meaning it is causing documented ecological damage.

Ecological impact: Brazilian pepper is particularly devastating in Central Florida, where it:

• Invades pine flatwoods, sandhills, mangrove communities, and disturbed areas
• Forms dense, impenetrable thickets up to 30 feet tall
• Shades out all native groundcover and understory plants
• Produces berries that are spread by birds, creating satellite infestations
• Produces allelopathic compounds that inhibit native seed germination

Management:

1. Forestry mulching: Highly effective for large-scale removal of Brazilian pepper thickets
2. Cut-stump herbicide: Triclopyr or glyphosate applied to fresh-cut stumps
3. Basal bark treatment: Effective for scattered individual trees
4. Follow-up: Brazilian pepper produces abundant seed that is spread by birds. Monitor for new seedlings for 3–5 years after treatment.

Japanese Climbing Fern (Lygodium japonicum)

Identification: A climbing fern with delicate, lacy fronds that twine around and over any available support structure — trees, shrubs, fences, power lines. The fronds are light green and compound, with distinctive finger-like leaflets. Unlike most ferns, it climbs, which makes it immediately recognizable.

Origin and spread: Native to Asia, introduced to the Southeast as an ornamental. It has become a serious problem in Florida and the Gulf Coast states, where it:

• Smothers native vegetation by climbing over and shading out trees and shrubs
• Forms dense curtains over the forest canopy
• Creates ladder fuels that carry fire into tree canopies, killing mature pines
• Is extremely difficult to control once established

Management:

1. Herbicide: Glyphosate or metsulfuron methyl applied as foliar spray. Careful application is needed to avoid damaging native vegetation.
2. No mechanical treatment alone: Cutting or mulching climbing fern without herbicide stimulates spore production and resprouting.
3. Fire considerations: Japanese climbing fern acts as a ladder fuel, carrying fire from the ground into tree canopies. It should be controlled before prescribed burning to prevent crown damage.

Nandina (Nandina domestica)

Identification: Also called heavenly bamboo, nandina is an evergreen shrub with compound leaves that turn red in winter. Clusters of bright red berries are visible from fall through spring. It is commonly planted as an ornamental but escapes cultivation readily.

Ecological impact: Nandina berries contain cyanide compounds that are toxic to birds. Large quantities of berries consumed by cedar waxwings and other fruit-eating birds can be lethal. In forests, nandina forms dense understory patches that displace native shrubs.

Management: Cut-stump or basal bark herbicide treatment. Removal of ornamental plantings near natural areas is recommended.

Integrated Invasive Species Management

The Three-Tool Approach

Effective invasive species management in the Southeast almost always requires integrating three tools:

1. Mechanical treatment (forestry mulching, hand cutting): Removes the above-ground biomass, restores access and sight lines, and prepares the site for herbicide application and prescribed fire.

2. Herbicide: Prevents regrowth from stumps, roots, and rhizomes. Without herbicide, many invasive species — particularly privet, tallow, and cogongrass — will resprout more vigorously than before treatment.

3. Prescribed fire: Maintains the open, fire-adapted conditions that favor native species over invasive species. Most southeastern invasive plants are fire-sensitive; most native plants are fire-adapted. Regular prescribed fire shifts the competitive balance back toward native vegetation.

Timing and Sequencing

The order and timing of treatments matters:

1. Mechanical treatment first: Remove the bulk of invasive vegetation. For large infestations, forestry mulching is the most efficient method.
2. Herbicide within 24–48 hours: Apply cut-stump herbicide to all freshly cut stumps of sprouting species. This window is critical.
3. Monitor for 3–6 months: Watch for resprouts, new seedlings, and missed individuals.
4. Foliar spray follow-up: Treat resprouts and new growth with foliar herbicide application.
5. Prescribed fire at 6–18 months: Once the site is in burnable condition, conduct a prescribed burn to kill small invasive seedlings, stimulate native groundcover, and maintain open conditions.
6. Long-term monitoring: Annual monitoring walks with spot treatment of new occurrences. The cost of annual monitoring is a fraction of the cost of re-treating a full-scale reinfestation.

Prevention

The cheapest invasive species treatment is prevention:

• Clean equipment: Forestry equipment, ATVs, and vehicles can spread invasive species seeds and plant fragments between properties. Require equipment cleaning before entering your property.
• Monitor property boundaries: Invasive species often enter from adjacent properties along roads, fence lines, and waterways. Early detection along boundaries prevents interior infestations.
• Avoid planting invasive ornamentals: Many invasive species were originally introduced as ornamental plants. Do not plant nandina, Chinese privet, Chinese tallow, or other known invasive species near natural areas.
• Report new infestations: Many states have invasive species reporting programs. Early reporting helps coordinate regional management efforts.

EQIP Funding for Invasive Species Management

Invasive species management is a high-priority practice for NRCS EQIP funding in the Southeast. Relevant practice codes include:

• Herbaceous Weed Treatment (Code 315): Covers herbicide application for invasive grasses (cogongrass, etc.)
• Brush Management (Code 314): Covers mechanical removal of invasive woody species
• Forest Stand Improvement (Code 666): Covers removal of invasive trees as part of forest health improvement
• Prescribed Burning (Code 338): Covers fire as a component of invasive species management

An EQIP application that combines mechanical removal, herbicide treatment, and prescribed fire for invasive species management is exactly the type of multi-practice, conservation-focused application that ranks well in the competitive process. See our EQIP guide for application details.

TreeShop provides comprehensive invasive species management services across Central Florida and the Southeast, integrating forestry mulching, herbicide application, and prescribed fire preparation into effective, long-term invasive species control programs.

Frequently Asked Questions

How do I know if I have invasive species on my property?

Most southeastern properties have some level of invasive species presence. A property walk with a knowledgeable land manager or forester can identify the species present, assess the severity of the infestation, and recommend management strategies. You can also use the free identification resources available from your state’s Invasive Plant Council or Cooperative Extension Service.

Can I ever fully eradicate invasive species from my property?

For some species (Brazilian pepper, Chinese tallow) on small to moderate properties, near-complete eradication is achievable with persistent management over 3–5 years. For other species (cogongrass, Japanese climbing fern), eradication is extremely difficult and long-term suppression may be a more realistic goal. The key is preventing re-infestation from adjacent properties and seed sources.

Is herbicide safe to use in my forest?

When applied according to label directions by a trained applicator, the herbicides commonly used for invasive species management (glyphosate, triclopyr, imazapyr) have well-characterized safety profiles and minimal environmental impact. Targeted application methods (cut-stump, basal bark, hack-and-squirt) minimize off-target exposure. The ecological damage caused by unchecked invasive species infestations far exceeds any risk from properly applied herbicides.

Should I treat invasive species before or after forestry mulching?

For most woody invasive species (privet, tallow, Brazilian pepper), forestry mulching first followed by immediate cut-stump herbicide is the most effective approach. For cogongrass, herbicide must be applied BEFORE any mechanical treatment — mulching cogongrass without prior herbicide actually spreads it by fragmenting and distributing rhizomes.

How much does invasive species management cost?

Costs vary widely depending on the species, severity of the infestation, and acreage. General ranges for common treatments in the Southeast:

• Forestry mulching of invasive thickets: $1,500–$3,500 per acre
• Cut-stump herbicide application: $100–$300 per acre
• Foliar herbicide spray (cogongrass, etc.): $75–$200 per acre
• Annual monitoring and spot treatment: $25–$75 per acre With EQIP cost-share at 50–75%, landowner costs can be reduced significantly.