COLUMN: A look at Iredell's most invasive plants

By: Amanda Taylor | Statesville Record & Landmark
Published: September 16, 2011

An invasive plant is defined as a non-native species that causes damage. One of the main problems with invasive plants is that they can crowd out native vegetation, and so reduce food and shelter for wildlife. Ironically, most invasive species were introduced as ornamental plants for landscaping. That’s not to say that all introduced species become invasive.

Whether or not a plant is defined as invasive is very geographically specific. That is, what is invasive here may not be invasive 100 miles from here. The invasiveness of a plant is related to the topography, weather, etc. of the area in question.

Some of the most common invasive trees we see in our area are princess tree, tree of heaven, and “Bradford” (Callery) pear trees. Despite their pleasant sounding names, these species are invasive and are not recommended for planting in our area.

Princess tree (Paulownia tomentosa) is easily identifiable by its huge, heart-shaped leaves, which are fuzzy on both sides. These trees have pecan-shaped nut capsules and purple flowers in the spring. Princess trees grow very rapidly and will sprout from the roots. If you’ve ever tried to remove this plant from your yard, then you know what a problem the root sprouts can be.

Tree of heaven (Alianthus altissima) is also rapidly growing, with sprouts that can grow up to 14 feet during the first year. Crushed leaves are supposed to have an odor like peanut butter (although I’ve never been able to smell this). The trees bare clusters of yellow flowers in May.

Bradford pears are one of the most common trees in Iredell landscapes. They are notorious for having weak wood (as well as other problems), but they will also readily invade disturbed areas and displace native vegetation. Birds spread the seeds of these trees.

Invasive plants are usually difficult to remove (otherwise they wouldn’t be invasive). So before attempting to remove them, be prepared for an arduous battle. I always tell people that they have to be more persistent than the plant. Removal methods involve cutting down the plants, digging out the roots, and/or applying an herbicide.

This article is a very bare-bones description of the invasive plant problem in our area. For more information on invasive plants in the Southeast, visit http://www.ncsu.edu/goingnative/howto/mapping/invexse/index.html.

Amanda Taylor is an agriculture agent (horticulture) with the NC Cooperative Extension Service in Statesville.