Do You Have Invasive Plant Issues?

LITCHFIELD — A forum on invasive plants is scheduled for Thursday, October 19, at White Memorial Conservation Center. The forum will bring together a diverse group of specialists to discuss the issues of invasive plant control. Speakers will include representatives from the nursery industry, landscaping specialists, land trusts, environmentalists, government and research organizations.

This is the first in a three-part training series being held to promote knowledge and understanding of invasive plants. The other two parts will include experts on control strategies during the winter, and a field identification session next spring.

For information on the training series call the Natural Resources Conservation Service at 860/626-8258.

Non-native invasive plants compete aggressively, leading to the local exclusion of native plants. Invasive plants can disrupt entire ecosystems by changing the make-up of plants in native communities. Once established, invasive plants spread quickly into new ranges.

The spread of non-native, invasive plants is regarded by some experts to be the second most important threat to native species. Examples of non-native invasive plants include Japanese barberry, Asiatic bittersweet, burning bush, some honeysuckles, multi-flora rose and purple loosestrife.

One needs a geographical context for calling a species non-native. Non-native to New England may be native to North America. Black Locust is native to the south and southwestern United States. It was introduced to Connecticut. Black locust trees were planted near houses for use as lightning rods, because the tree attracts lightning. Today black locust is on the Connecticut Invasive Plants list.

Many common garden plants are considered to be invasive by gardeners who strive to keep them under control. A non-native plant only makes it onto the invasive plant list if it can jump over spatial gaps and survive in the wild.

Dandelion is not native, not invasive, and not dominant in natural systems. Periwinkle (blue myrtle) does not jump over spatial gaps. It only grows out from where it is planted. Therefore Periwinkle is not native and not on the CT Invasive Plant list. The same goes for day lilies and English ivy. White clover and orchardgrass are non-native but not invasive.

There are several common attributes of invasive plants. They tend to have high seed and fruit production, or fast vegetative reproduction. Invasive plants have an effective dispersal mechanism. They establish easily, like garlic mustard. They grow rapidly or have some other competitive advantage such as leafing out early or holding leaves longer in the fall. Invasive plants tend to persist over time in an area. An example is Black swallowort, a persistent non-native invasive vine.

Invasive plant species grow where the land has been disturbed. This may be a natural disturbance such as stream bank erosion. The invasive Japanese knotweed is establishing along major rivers in Connecticut, along the natural disturbance of scoured banks.

Human land disturbance – including abandoned agricultural fields, gravel excavations, pond maintenance, roadways and construction sites – can also contribute to distribution.

Contact project coordinator Kathleen Johnson for additional information including directions to White Memorial Conservation Center at 860/626-8258.