Exotic invasive plants: Know what not to plant

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Exotic invasive plants: Know what not to plant

Gardening in our area is as much about knowing what to plant as it is about knowing what NOT to plant. Many plants grow well here — some so well that we wish we had never laid eyes on them. Of particular concern are the exotic invasive plants that we planted because they were beautiful and before we learned of their destructive nature.
Many of these plants were brought to our country because of their ornamental attributes. Gardeners who know about them and plant them anyway ignore the findings of the University of Florida IFAS Assessment, the Florida Exotic Pest Plant Council, the Southeast Exotic Pest Plant Council and other agencies whose job it is to identify exotic invasive plants and educate the public about them.
•A Thug to Avoid
One beautiful botanical brute we need to learn about is coral ardisia. It has dark green, glossy leaves, white or pinkish flowers, and clusters of showy scarlet berries. One look at these attractive plants in full berry is enough to make most gardeners want to include them in their landscape. Unfortunately, the plants can still be bought at many nurseries.
Planting instructions suggest that coral ardisia be planted in rich, deep soil with lots of organic matter. Shade to partial shade and moist, well-drained soil are preferred, and a good layer of mulch will help maintain soil moisture and enrich the soil as it decomposes. This pretty well describes a natural area just ripe for coral ardisia to get a foothold.
•Reasons for Concern
The red berries of coral ardisia are attractive to birds, particularly cedar waxwings and mockingbirds. They carry the seeds into natural areas. Seeds germinate readily and are viable for a long time.
Problems with coral ardisia are not limited to Florida. It is naturalized on two islands in Hawaii. In Louisiana it has invaded natural areas in several places, and it has been reported in Texas where it dominates the understory in parts of two reserves.
Coral ardisia is listed as a Category I exotic invasive plant for Florida by the Florida Exotic Pest Plant Council. According to the council’s definition, it is an exotic that is altering native plant communities by displacing native species, changing community structures or ecological functions, or hybridizing with natives. This definition does not rely on the economic severity or geographic range of the problem, but on the documented ecological damage caused.
We know that all exotic plants are not invasive. However, those that are wreak havoc in our natural areas. They spread easily into native plant communities and never encounter the natural enemies that controlled their growth in their homeland. In natural areas, they can cause a reduction in biodiversity, loss of habitat and food sources for native insects, birds, and other wildlife, and changes to natural ecological systems.
Learn to recognize this exotic invasive plant and ban it from your garden. Pass by it at the garden center, no matter how beautiful you think it is. Just harden your heart and keep going. You’ll do your landscape a favor as well as some natural areas that are within a bird’s flight from your home.
Marie Harrison is a Master Gardener Volunteer with the University of Florida IFAS Extension in Okaloosa County. Her books, “Gardening in the Coastal South,” “Southern Gardening, an Environmentally Sensitive Approach,” and “Groundcovers for the South” are now available. Visit her at her Web site www.mariesgarden.com to read gardening hints and other information of interest to gardeners.

At a Glance
Common names: Coral ardisia, coralberry, Christmas berry, Hilo holly, marlberry, ardisia
Scientific name: Ardisia crenata
Pronunciation: ar-DIZ-ee-uh kre-NAY-tuh
Hardiness: USDA Zones 7-10
Salt tolerance: Moderate
Family: Myrsinaceae (Myrsine)
Size: 2 to 6 feet tall/2 to 3 feet wide
Origin: Japan to north India
Relatives: Ardisia escallonoides (marlberry); Ardisia elliptica (shoebutton)
Propagation: Seeds; volunteer seedlings