Instructor: Dr. Rodrigo Diaz, firstname.lastname@example.org
A wild specimen of coral ardisia.
Coral ardisia (Ardisia crenata) is an invasive evergreen shrub native to southeast China. It was introduced as an ornamental in the early 20th century. Coral ardisia was used as a landscape plant in Florida and has since spread to other states in the southeast including Louisiana and Texas.
Coral ardisia sightings map from EDDMapS. Populations may exist outside of green parishes but have not been officially reported.
Coral ardisia has a high shade tolerance and can be found growing in wooded areas. The plant prefers moist soils with rich organic matter, but will rot in flooded areas[2, 3]. The bottomland hardwood forests of Louisiana provide a perfect environment for this invasive species.
Coral ardisia is easy to recognize in the landscape. The plant typically reaches about three feet tall and has dark-green, waxy foliage. Leaves have a scalloped, or crenate, edge to them that is totally different from other plants in Louisiana. Bright red berries grow as bunches on older branches and remain attached to the plant year-round. Plants form clumps with multiple stems arising from one root system .
Leaf arrangement on stem.
Reproduction can occur vegetatively or through the seeds found within the berry. New stems grow from underground rhizomes. Each berry contains a single, large seed within. Berries can easily detach from plant stems and fall to the soil directly below the plant. Birds will eat the fruit and drop the seed, dispersing the plant further. Seeds have a germination rate of 84-98% and can survive for years until environmental conditions become favorable [3, 4].
Berries on end of stem.
Coral ardisia disrupts the natural succession of forests and prevents new growth from filling in cleared space. Established populations form thick mats that completely cover the ground and can absorb up to 70% of sunlight that reaches the forest floor. Blocking out that much sunlight means other plants do not have the energy to grow and are crowded out by the thick growths of coral ardisia. Being an evergreen, coral ardisia can grow while other plants are dormant during the Winter, giving it a head start over native species . The result is a monoculture of only coral ardisia around the forest floor. The outcompeting of native plants removes a vital food source for animals that cannot eat coral ardisia and further damages the ecosystem at higher trophic levels.
Landscape dominated by coral ardisia.
Prevention is the best approach to manage invasive species. DO NOT plant coral ardisia in home gardens, use for compost, or transfer plant material to new areas. Live plant material should be disposed of in sealed bags to prevent spread.
Smaller plants can be pulled by hand, but larger individuals may require digging out with a shovel. Berries should be removed from the plant first and placed in bags to prevent them from falling off and sprouting new plants. You should make sure that nothing is left in the ground as the plant can regrow from rhizomes left in the ground .
Prescribed burns are not an effective answer as plants regrow after fire damage . Herbicides, like glyphosate, are available and effective at killing infestations, but care must be taken to not accidentally kill native species. Cleared areas should be checked periodically and any regrowth removed to prevent repopulation .
Roots, leaves, and berries in full view.