Invasive Species Management

What It Is

Invasive species management is the systematic control of non-native plant species that threaten native ecosystems. Alabama has more forestland impacted by invasive plants than any other southeastern state, and the Cumberland Plateau region faces heavy pressure from several high-priority species.

Invasive plants arrived primarily through ornamental horticulture (privet, honeysuckle), deliberate government programs (kudzu was promoted by the Soil Conservation Service in the 1930s–40s), agricultural trials (cogongrass), and accidental introduction. Once established, they can be extraordinarily difficult to remove — but with the right species-specific approach, control is achievable.

Critical principle: Control strategy must be species-specific. Generic “spray and burn” approaches fail, and in the case of Chinese privet, fire alone can worsen the infestation by stimulating resprouting.

Priority Invasive Species

Chinese privet (Ligustrum sinense): The most problematic invasive shrub in the region. Forms impenetrable thickets in bottomlands and riparian zones, completely excluding native vegetation. Control: cut stump with triclopyr, basal bark treatment, or mechanical removal where feasible. Multi-year follow-up is essential.

Kudzu (Pueraria montana): The iconic invasive vine. Control: repeated foliar herbicide applications plus targeted root crown treatment. Damaging the root collar is highly effective. Multi-year effort required. Goats and cattle can help weaken stands as a supplement to herbicide.

Japanese honeysuckle group (Lonicera spp.): Multiple species with different growth habits — the region hosts 3–4 species. Control: foliar spray with glyphosate or triclopyr in late fall/winter when natives are dormant. Fire alone does not control honeysuckle effectively.

Cogongrass (Imperata cylindrica): An aggressive grass spreading rapidly in the region, identifiable by its off-center white midrib. A state-listed noxious weed — report new infestations. Control: glyphosate or imazapyr, multiple applications. Do not burn without prior herbicide treatment — fire spreads cogongrass.

Japanese stiltgrass (Microstegium vimineum): Annual grass forming dense mats in forest understories. Control: pre-emergent herbicide or late-summer foliar treatment before seed set; mowing before seed set reduces spread.

Paulownia / Princess tree (Paulownia tomentosa): Fast-growing tree spreading prolifically from seed and root sprouts. Added as a priority species based on scientific review. Control: cut stump or basal bark with triclopyr.

How It’s Done

Effective invasive control follows this sequence:

1. Species identification — treatment must match the target species
2. Timing — many treatments are most effective in specific seasons
3. Treatment — herbicide (foliar, basal bark, cut stump, or hack-and-squirt), mechanical removal, or combination
4. Follow-up — invasive control is never one-and-done; monitoring and retreatment over 2–5+ years
5. Native establishment — filling the vacated space with desirable native plants prevents reinvasion

Herbicide basics:

• Glyphosate: broad-spectrum, no soil activity, relatively safe near water
• Triclopyr (ester form): selective for broadleaves and woody plants; use for basal bark treatment
• Always follow the label — the label is the law

Expected Outcomes

• Year 1: Significant reduction in invasive cover; native plants begin to emerge from suppressed seed bank
• Years 2–3: Native vegetation recovering in treated areas; continued follow-up needed on resprouts
• Years 3–5: Native plant community reestablishing; habitat function improving
• Ongoing: Annual monitoring and spot treatment to prevent reinvasion