Wresting Control from Foreign Invaders

Sometimes by plan and other by circumstance we have drastically changed the face of America’s natural occupants. We’d not only displaced plants and animals with our development, but we’ve further degraded natural ecosystems by introducing exotics.

When we first acquired these properties in mid-2003 they had been abandoned for many years. The original home site (now to support Upstate House) and the adjoining virgin lot (the planned Woodland Garden) were dense vegetative mats of underbrush, vines and growth of all kinds – many unfriendly, such as the all-too-native poison ivy that in some places was of near commercial size. Carlton Owen spent the better part of two months using late summer evening light and weekends to clear the downed limbs, poison ivy stands and the vicious patches of wait-a-minute vine – Smilax sp.

But that’s just the beginning of the story. This property, like many others in the U.S., boasts a long list of exotic species – some brought intentionally by former property owners; others that have just hitched their way aboard. Before we could begin any serious efforts to restore native vegetation we would have to remove exotic vegetation – the dominate vegetation in both the mid-story and under-story of both properties.

Many are beginning to realize the impact that exotic animals and plants are having on native ecosystems. To understand the magnitude of the problem we need only look to birdlife in our cities to see pigeons, English house sparrows and starlings as the most common of all birds or to our yards where English ivy, periwinkle and Japanese privet thrive. All are highly competitive species that were introduced either intentionally or unintentionally.

The Upstate House and Woodland Garden are poster sites for invasive exotics. In fact if we had conducted a scavenger hunt for species on the South Carolina list of Invasive plants (http://swcs.tripod.com/invasiveplants.htm) we would have had a great start without going anywhere else. Of the 61 plants (trees, vines, shrubs, grasses and herbs) on the list, our site held 13 at first count. Below is a listing of species found on the site thus far, noted by their type and threat category.

Trees
Significant Threat:
Ailanthus altissima, Tree-of-Heaven

Shrubs
Severe Threat:
Ligustrum japonicum, Japanese Privet
Rosa multiflora, Multiflora Rose

Significant Threat:
Mahonia bealei, Leatherleaf Mahonia
Nandina domestica, Nadina or Sacred Bamboo

Vines
Severe Threat:
Lonicera japonica, Japanese Honeysuckle
Pueraria lobata, Kudzu
Wisteria sinensis, Chinese Wisteria

Significant Threat:
Hedera helix, English Ivy

Grasses, sedges
Significant Threat:
Phyllostachys aurea, Bamboo

Herbs
Watch:
Liriope muscari, Liriope or Monkey Grass
Vinca minor, Common Periwinkle

Other Exotics Abound
While bamboo, common periwinkle, wisteria and kudzu were among the most common of undesirables, there were a number of other significant plants that were not on the invasive exotic lists but perhaps should be.

Chinese mulberry, a tree that is causing such severe allergy problems in Pakistan that the government there has dictated their removal in all cases except where grown in plantations for commercial purposes, is common in the mid-story. The tree produces a white or near colorless berry similar in appearance to our native, and more tasty, relative. Japanese buckwheat, a prolific plant grew in dense stands on sunny portion of the property with other stands along nearby Richland Creek. Scattered specimens of Yucca sp. from the southwestern U.S. and money plant (Lunaria annua) noted for its beautiful purple flowers and attractive “silver dollar” seedpod are also present.

The Plan of Attack
Our first goal will be to remove some of the more invasive of species – those that threaten to continue their spread. Among the first targets are Tree-of-Heaven, bamboo, kudzu, periwinkle and monkey grass. It will likely take a couple of years or more to completely eradicate undesirable species from the site and slowly implement our restoration strategy.