Stop the invaders!: Non-native plants harm Louisiana ecosystems

By Wesley Harris

Non-native, invasive species are those plants introduced into an area and spread aggressively, displacing native plants essential to wildlife. Invasive species are a problem because they:

–Compete for the same natural resources and life requirements as native species—food, water, space, shelter

–Crowd out native species essential for wildlife survival, degrading local ecologies by disrupting the food chain

–Alter patterns of natural disturbance

–Degrade aquatic habitats and clog waterways

–Decrease biodiversity

–Lead to a host of economic problems. 

Most invasive species come from Asia and were originally imported for landscaping. Naturalists condemn the use of these plants and advocate for their destruction. 

Chinese Tallow (Triadica sebifera) Other names: Popcorn Tree, Chicken Tree

Chinese tallow is a medium-sized tree that will often colonize open fields or neglected fence lines. The tree’s deep red and orange fall color disguises its destructive nature. Chinese tallow can alter soil chemistry due to the high concentration of tannins found in its leaves. Its sap is toxic to animals.

Chinese tallow grows rapidly in both sun and shade, is tolerant of both shallow flooding and periods of drought and has no known diseases or predators in this region. It makes enormous quantities of seeds starting at an early age. Birds spread the seeds, resulting in dense stands that completely out-compete native tree species.

If you have tallow on your property, environmental scientists highly recommend you kill it, take it out, and plant something native. Tallow costs hundreds of thousands of dollars to control on various public and private lands across Louisiana. Native alternatives include titi (leatherwood), (Cyrilla racemiflora), sourwood (Oxydendrum arboretum), and mayhaw (Crataegus opaca). 

Mimosa (Albizia julibrissi) trees produce thousands of seeds in long pods. The seeds seem to sprout everywhere, resulting in encroachment on native species. It does not tolerate deep shade, so it is mostly found along ditches and open sunny areas like the tallow.

Common Privet (Ligustrum sinense) Other names: Chinese Privet, Chinese Ligustrum, Small-Leaf Privet. Common privet is a multi-stemmed bush that grows as high at 15 feet, often forming very dense hedges along fence lines or in the understory below larger canopy trees. It often colonizes in lawns and invade nearby areas. The bush sprouts from adventitious root suckers and can rapidly cover an area so densely that it becomes impossible to walk through. The Bluebonnet Swamp Nature Center in Baton Rouge was thoroughly invested with privet after Hurricane Gustav took down many large canopy trees. The introduction of more sunlight to the forest floor encouraged the spread of the privet to the detriment of native species. Birds often spread privet seeds after ingesting the dark blue drupes. Although a few birds eat the fruit, this does not make privet an acceptable planting because the non-native crowds out natives essential for more species of birds and other wildlife.

Tree Ligustrum (Ligustrum japonicum) Other names: Wax-leaf Privet, Japanese Privet. Ligustrum is a classic plant of the old South, having been used in southern gardens for decades. It colonizes wood edges and disturbed areas within unbroken forest and is spread by birds which eat the drupes. Invasive ligustrum can reach 30-40 feet tall with multiple stems and can persist in shady conditions. Do not cultivate either the waxy- or non-waxy varieties of privet. Both may displace native species where they aggressively spread far beyond your home’s boundaries. 

Elephant Ear (Colocasia esculenta). Elephant ears possess great ornamental appeal, but they spread in very dense clumps in wetlands and along the edges of swamps and freshwater shorelines which displaces native vegetation.

Because of the devastating impact human development has had on wildlife habitat, use native plants in your yard or landscape. Some non-native species are okay, but research before you plant. Common non-native, non-invasive species suitable for Louisiana include Asian Azaleas (Rhododendron spp.), common banana (Musa spp.), and Camellias (Camellia spp.). For more information, visit

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