They come to us in many innocuous ways, from packages from overseas, to clinging onto the bottom of our fishing boats. They are the invaders that cause so much trouble when they go unchecked. I am talking about invasive species. From the long-horned asian beetle to the goby, from giant hogweed to feral swine. These non-native, introduced species of fish, plants, mammals, and insects have come from overseas and without any natural checks to keep them from populating our waters and woods at a very fast rate, causing alarming damage. Most of which goes unchecked and unseen until it is at the point where the invasives are out of control.
While there are thousands of invasive species in the United States, I am just going to cover the most common and destructive found here in our area of New York, including some in my own backyard. Here, I will introduce you to the critters and alert you to the damage they have done and will continue to do if they are left to populate without our intervention. I will give you a brief history of how they got here, what they look like, what damage they have done and what is being done or what you can do to eradicate them from our area.
In this first of a series, I will start out with the terrestrial plants. One invasive that can be found in most woodlots throughout the county is the garlic mustard plant. Garlic mustard is an invasive herb that has spread throughout much of the United States over the past 150 years, becoming one of the worst invaders of forests in the Northeast. Garlic mustard originated in Europe and parts of Asia. It is believed that it was purposely introduced into our country for medicinal purposes and food. The earliest known report of it growing in the United States dates back to 1868 on Long Island, NY. These three foot tall plants are biennials. The first year they form a low growing rosette that most probably overlook. The second year the plant forms a three foot stalk that contains the seed pods that help it spread. Each pod contains up to 28 seeds, with 22 pods present in most plants...Thus easy math will show you that one plant can produce about 600 seeds and obviously spread quite rapidly.
Garlic mustard has the potential to form dense stands that choke out native plants in the understory by controlling light, water, and nutrients. Garlic mustard is one of the plants able to dominate the understory in forests. Altering plant diversity can cause a change in leaf litter on the forest floor, potentially impacting salamanders and snails. Insects, including some butterflies, may be affected through the lost diversity in plants. Garlic mustard may also affect the tree composition by creating a selective barrier that some seedlings may not be able to overcome.
It doesn't appear that deer and woodchucks eat much of this. I have not seen any predation by herbivores on my property, where the garlic mustard grows along my drive and other trails through the woods. So, removal of the plant has been by pulling it by hand. They are very easy to pull out and I toss the stems and roots in a pile to compost, but do not use this compost in any of my gardens. In my research, it has been said to pull the plants before the seed pods form and to continue to do so yearly, as the seeds can lay dormant in the ground for up to five years. It is cumbersome, sometimes back breaking work, but it is the only way to eradicate the plant inexpensively. One story I heard is that inmates in Pennsylvania are used to pulling the plants, then the plants are taken back and cooked like mustard greens. I tried it, they are not that bad tasting if you use the smaller, younger leaves.
Chemical applications can be effective for controlling garlic mustard, particularly in areas too large for removal by hand. Glyphosate-based herbicide such as Roundup can be an effective. Unfortunately, glyphosate herbicides are non-selective, so you could wind up killing a lot of native plants and cause more damage to than good. The best method for controlling garlic mustard, or any other invasive plant, is to prevent its establishment.
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Several species of honeysuckle found in NY are characterized as invasive, including, Morrow’s, Tatarian, Amur, and Japanese. All four species have a similar range of habitats, including, abandoned fields; pastures, early successional, open canopy, and planted forests; along the edge of woodlots; floodplains; highway, railway and utility rights-of-way; open disturbed areas; vacant lots; edges of lawns; and, gardens. All four grow best in full sun.
These honeysuckles, natives to Asia, Russia, Japan, and Korea are believed to have been introduced into North America as early as the 1750s. The honeysuckles found in my woodlot were all planted with the advice of the DEC back in the late 1970s and early 1980s. I was told by the foresters that they were good plants that provided food for different bird species. I bought hundreds of honeysuckle plants every year from the DEC nursery in Saratoga Springs and planted them throughout my property thinking I was doing a good deed. These honeysuckles are now considered a weed, an invasive pest and in my forest management plant. The DEC now says to cut them all out. Most honeysuckles though have been planted as ornamentals, and are easily spread by birds that eat the berries as a last food resort.
Three of the honeysuckles are perennial shrubs, with Japanese honeysuckle being a perennial woody vine. The shrub forms range from six to 15 feet in height, while vines can reach 30 feet in length. The egg-shaped leaves range from 1 to 3 inches in length and are arranged oppositely along stems. Invasive honeysuckles begin flowering from May to June and bear small, very fragrant tubular flowers ranging from creamy white through various shades of pink to crimson. Bright red to dark black berries are produced throughout the summer and into the fall. Stems of all four are hollow.
