Wild Green Yonder: Give them an inch, and they'll take an acre

What's the big deal about non-native invasive plants, and promoting native plants - the annual economic losses due to invasive species in Virginia are estimated to exceed $1 billion. This figure includes damage to crops and pasture, forest losses, damage from insect and other invertebrate pests, human diseases and associated control costs.

Wild Green Yonder: Give them an inch, and they'll take an acre
Article from Virginian-Pilot/Lawn&Garden

On my daily commute to the Norfolk Botanical Garden, I often look out at the green spaces on the highway. These tangled masses of trees and shrubs struggle to support the weight of massive vines. These spaces are not kept by any gardeners; nothing is planted and nothing is removed other than a dead tree or two. They are natural areas, a snapshot of nature on the side of the road.

It’s nice to see a pop of color every so often, and at certain times of the year we get grand shows of flowers sprawling out on each side. One such event is in early spring when the Bradford pear trees bloom. As if overnight, hundreds of seemingly dead trees fill the highway with pretty white blooms. Soon after, the sweet smell of honeysuckle fills the air. With summer comes the huge purple drooping flowers of the wisteria vine. Later we are showered with the airy pink inflorescence of the mimosa tree.

Motorists in Hampton Roads also see what I see. Most may think the seasonal color is pretty, and they may even go to the local nursery and try to purchase “the white blooming tree that grows along the road.” Most are familiar with the term “invasive species,” but they can’t fathom that it would apply to a plant with a pretty bloom, or better yet a plant that one can purchase at a garden center. Invasive plant species are no joke and are disguised most times by a pretty bloom or smell.

The Department of Conservation and Recreation defines an invasive species as “non-native (aka alien, exotic, or nonindigenous) plants, animals, and diseases that cause or are likely to cause ecological and economic harm.” Annual economic losses due to invasive species in Virginia are estimated to exceed $1 billion. This figure includes damage to crops and pasture, forest losses, damage from insect and other invertebrate pests, human diseases and associated control costs.

Further, impacts of invasive species are exacerbated by climate. Virginia has 90 invasive plant species, many of which were brought from Europe and Asia for ornamental or culinary purposes. Invasive plants can overtake native plants, as well as eliminate or diminish resources like food and cover for wildlife. Invasive species also can disrupt pollination, change the flora gene pool through hybridization and alter the soil chemistry, making it more difficult for native plant species to flourish.

For example, parrots feather (Myriophyllum aquaticum) is an invasive plant in North America that grows in freshwater streams, ponds, lakes, rivers and canals that have a high nutrient content. In large numbers, the plants make a dense mat on the water’s surface. Because of this, they shade the water from sunlight and cause native plants to die because of light deficiency. The organisms that feed on the native plants can die off because of starvation.

The dense mats also cause problems for recreation. Swimmers and boat propellers can become entangled. Large colonies of parrots feather may promote the spread of mosquito-borne disease.

Here at NBG we are confronting this problem full force. The first step to managing invasive species is knowing what they are. The DCR has done that work for us at www.dcr.virginia.gov. From there, we identify, treat and/or remove invasive species from our 175 acres. Protection of our native green spaces should be a goal for which we all strive.