Invasive Gardening as Ecological Pollution

An expert explains why it’s important to ‘Know Before You Grow’

Burning Bush

Burning Bush

by Jess J.Käthe

We had been walking the roads and trails, surveying campsites, and admiring scenery for five or six hours when we reached the day-use area at North Lake. 

Searching for terrestrial invasive species has become second nature as I’ve scoured landscapes with the Catskill Center’s Invasive Species Strike Team and seeing a native ecosystem flourish, even under the pressure of consistent seasonal tourism, made it a truly enjoyable day. The trail led to the asphalt, which led to a mowed picnic area peppered with birches surrounded by laurel. At the base of each birch we noticed a messy shrub adorned with hundreds of tiny crimson bead-like fruits. 

Upon closer examination, we affirmed a familiar target species, Japanese barberry, which had been planted intentionally between the picnic tables, and had begun to spread into the treeline among the laurels. Woefully, we unpacked our data collection instruments, wondering how many of the tiny brilliant red berries had been already distributed into the pristine forest.  

An invasive species is one that is introduced to a region where it would not normally grow. With no natural competitors, it is able to overtake other organisms in the ecosystem and it has a high tolerance for a range of conditions. Barberry and other familiar non-native species are purposely introduced by the landscaping industry.. Although legislation has restricted the sale of some invasive species, cultivars of barberry (Berberis thunbergii) are still available for purchase. 

Japanese Barberry

Japanese Barberry

Before I became involved in the study of invasive species, I worked in garden centers where these non-natives were some of our bestsellers. Myrtle or pachysandra made a quaint groundcover, border privet and burning bush could be used as a fast-growing hedge for gardeners seeking  privacy. It was not until I found myself swinging a brushcutter into a thicket of burning bush at a removal site that I began to see the harm in my recommendations.  

In plain terms, the big name garden centers don’t make the legislation or ethics of conservation a high priority. There will always be burning bush available to those who seek it out. This places the responsibility of prevention in the hands of gardeners, a community that is often removed from the scientific aspect of what a garden can be. Aestheticism is an enjoyable, and profitable aspect of gardening, but when invasive species are introduced to the garden setting, it teeters on ecological pollution. 

An invasive species is one that is introduced to a region where it would not normally grow, so it is able to overtake other organisms in the ecosystem with no natural competitors, and a tolerance for a range of conditions. 

Plant Wise NY is a publication designed by the Cornell Cooperative Extension and NYS PRISMs to inform gardeners of this issue, using the slogan "Know Before You Grow." 1 Plant Wise includes recommendations for look-alike  native substitutes for common invasive landscape plants, such as swapping big bluestem (Andropogon gerardii) for Chinese silver grass (Miscanthus sinensis), virgin’s bower (Clematis virginiana) for sweet autumn clematis (Clematis terniflora), or highbush blueberry (Vaccinium corymbosum), for burning bush (Euonymus alatus). A visually similar blueprint can be carried out with these native species, effectively averting the ecological harm that results in $35 billion damage and treatment expenses per year in the U.S.  1  

When I encounter someone who expresses doubt on the invasives issue, I challenge them to glance at the roadsides the next time they find themselves a passenger on the thruway. I often give satirical "invasive tours"  while driving: "And on your right you can see a vast sea of phragmites" or "On your left, observe a woodland area completely engulfed in oriental bittersweet."  During the Victorian era when wreaths were traditionally made from bittersweet, no one suspected such a biological backlash; it was merely a pleasant embellishment around the home. But once you catch a glimpse of the skeletal leafless forests beneath the lush blankets of invasive vines that line the roads, you might think twice about purchasing a plant with an alias like "ground-cover." They’re cover, indeed; invasives have been shown to spread over one million acres of wildlife habitat per year. 

Gardening is a terrific way to spend time outdoors, but the responsibility of manipulating a green space is not one to take lightly. It is more than likely that the non-native landscape installations I’ve been involved with in the past will outlive me significantly, and will spread into the forest that I revere so greatly as a resident of the Catskill region. From one plant lover to another, I hope the choice to Know Before You Grow resonates thoroughly with all those who encounter the initiative, so that the Catskill Region herself can continue to show us how she gardens, birches, laurels, and all. 


1 Plant WIse: Know Before you grow is a gardener’s tip sheet published by The NYSDEC to help New Yorkers recognize and avoid gardening with  plants that can become invasive. 

Read + download Plant WIse at bit.ly/plantwise

- JJK