‘Tis the season for all types of plants to pop up out of the ground.
Each spring noxious weeds we couldn’t quite conquer the previous year come back. There are opportunist sprouts from seeds brought by the birds and wind. Hitchhikers arrive with nursery plants. This year we have the added challenge of plant thugs brought by hurricane Matthew.
Many of these unwanted plants are noxious and invasive weeds that arrived in the form of seeds that have germinated and are now growing rapidly. Others arrived as plant parts like stems, tubers and leaves that have taken root and are growing vigorously in their new home. They out compete other plants for sun water and nutrients. They are a detriment to the environment and landscape.
An invasive plant is one that is adaptable, aggressive and reproduces easily. Typically such plants have escaped from cultivation and moved on to crowd out native plants. Invasive plants many times are a foreign species that, like kudzu, was brought in to solve a problem; or plants that have sneaked into this country with foreign freight and then spread uncontrolled.
Nasty weeds like Florida betony, with its rattlesnake tail-like tubers, may have washed or blown in from a neighbor’s yard in the last hurricane. Interestingly, Florida betony is said to have first arrived on the SC coast with hurricane Hugo.
It is imperative to identify and control noxious and invasive plants early before they take hold and become established. Vines and plants with running roots are especially tough to control.
Be wary of any vine you did not plant. Vines to watch out for include Virginia creeper, smilax, Japanese honeysuckle, multiflora roses, wild blackberries and jessamine, among others.
Broad spectrum herbicides that contain glyphosate and triclopyr are effective for the control of invasive vines named in this article. Be sure to read and follow all label directions on pesticide containers. Eradication of invasive plants may require a multi-year effort. The most realistic and best control can be found by digging out as much of the root system as possible in combination with a carefully applied broad spectrum herbicide.
An herbicide with foliar or soil activity is typically not safe to other plants in a garden setting where it can kill nearby vegetation; or in an area that drains into a swail, creek or pond where it will damage the aquatic ecosystems.
The South Carolina government, in cooperation with other SC organizations has been vital in the identification of invasive plant species. They have designated noxious plants illegal to import, sell or distribute in the state. The SC Department of Natural Resources monitors 26 illegal aquatic plants. The Southeast Exotic Pest Plant Council has developed a list of Non Native Invasive Plant Species that is particularly useful for gardeners and landscapers. Google
se-eppc.org/southcarolina for more information and plant lists.
Many gardeners and professionals already know to be careful when they plant some plants on SC-EPPC lists. Ground covers like English ivy, vinca (periwinkle) and ajuga (bugle weed) and vining Sweet Autumn Clematis have a long reputation for their invasive nature. If gardeners plant such species they need to be aware that the plants will require control.
We need to avoid using other ornamental plants altogether. Chinese and Japanese ligustrum (privet), nandina, wisteria, mimosa, bamboo, Japanese barberry, Scotch broom, leatherleaf mahonia, Japanese honeysuckle, miscanthus sinensis, pampas grass, prickly pear, and liriope are a few of the invasive plants many of us use in our gardens. Be aware that eventually we need to replace them with native or well adapted plants.
A number of invasive plants are sold commercially in nurseries and catalogs. Stores and catalogs that sell in a large part of the country are the most likely sources. To their defense, a plant that is noxious in one region may not be a problem in another. The burden ultimately falls on consumers to take responsibility for what not to grow in their area.
If you are curious about an upstart you don’t recognize, why not dig it up, put it in a pot and see what it becomes.
Reach Debbie Menchek, a Clemson Master Gardener, at firstname.lastname@example.org.