by James P. Engel, © 2010
There it was just off the trail! I spotted it from a good 30 feet away. I thought about walking on, but when would I be back this way again? I wondered to my self; how many people had passed this way without noticing? innocently unaware of the future danger to this pristine place. I stopped. My wife and friends continued walking. It wasn’t very large but it was well anchored in the gravelly soil, tucked in between two maple roots. I didn’t have gloves to protect my hands from the spines, so I gently gripped the largest stems and pulled several times. The roots finally released their hold and I held in my hands the remains of a Japanese barberry.
My wife and friends had finally noticed my absence and returned to see what I was up to.
I didn’t need to explain to my wife as she is accustomed to my intolerance of invasive plants. I explained to my friends that this was a highly invasive plant and if left to grow would eventually spread and cause future harm to this unique biological area. By taking the time to stop and pull this one plant I helped protect this unique place from alien invasion.
Unfortunately, I have visited far too many natural areas and found them overrun with all types of invasive plants. No area is spared. The barberry I pulled was a good ¼ mile from the nearest road or house, surrounded by a mature hardwood forest. It doesn’t matter what level of legal protection the land might have, what the habitat is like, what the past history of the land is or how far it may be from people and civilization. All land is at risk; it only differs in the severity of the invasion and what the current and future threats may be. Nature preserves, park land, forest preserve, wildlife refuges, public and private land or your own property, is presently or will be, invaded and overrun with invasive plants if steps are not taken to control them.
All large infestations have one thing in common; they have been growing for many, many years, often 30 to 50 years or more. During all of this time no one noticed or took any action to control the spread. Every infestation begins with a single plant. The infestation slowly spreads when that one plant matures and begins to produce seed. As the years pass more plants begin to mature and contribute their seeds. The infestation picks up steam. The number of plants increases and the area invaded expands exponentially in relationship to the length of time the plants have grown and the amount of seed input. This pattern reveals the importance of early detection in reducing the risk from invasive plants.
There are two simple things a person can do to reduce the spread of invasives. The first step is to learn how to identify invasive plants and it is especially important to recognize them at the seedling or juvenile stage, when the plants are small. Identifying plants at this stage makes it far easier to prevent an infestation from getting started in the first place. Small plants are easier to remove than larger ones and often there are just a few plants that need to be removed. Seedlings can often just be pulled by hand which takes only a few seconds per plant.
You will need to learn how to identify each species of invasive plant that you may come across. This isn’t as difficult as it may seem. Typically at any one location there will onlybe one or two species you will need to identify. Each species tends to have morphological (physical) characteristics that distinguishes one plant from another.
Some invasive plants are extremely easy to identify at certain times of the year. In some species, such as Asian honeysuckle, the plants hold their leaves long past the time when all native plants have dropped their leaves. Honeysuckle is also the first plant to begin leafing out in the spring, earlier than any native species. Differences in fall foliage make identification easy for some species as the color differences are so pronounced. Leaf and bark color can also be used to distinguish one species from another. Leaves that are one shade of green will stand out against other plants whose leaves are a different shade of green. Difference in bark color, texture and the bark patterning will aid in identification especially during winter when the leaves have dropped. European buckthorn has very black bark and leaves that are dark green, colors that are represented in only a few native species. Buckthorn stands out against the lighter greens and bark color of similar looking native species.
Once you make a visual imprint in your mind of the shape, form and other identifying features such as color, fruit, texture etc., you will be able to repeatedly pick that species out from all the other background plants with confidence. A Japanese barberry has no look-a-like in the native shrub community. Common buckthorn might be confused with a small Black cherry sapling, but cherry does not have any thorns and the branching pattern is different. If there are no cherry growing in your woods then you don’t have to worry about misidentification.
Other morphological features or combinations of features can be used to identify specific invasive species. Autumn olive is easily identified by a silvery or whitish color on the underside of the leaf. Common and Japanese barberry are identified by the short spines along the stems, bright yellow of the stem pith and bright red berries that are prominent during winter. Oriental bittersweet can be spotted from a long distance by the bright yellow of its fall color and from the bright orange fruit that are visible after the leaves fall. Bittersweet is also recognized by its silvery gray bark and its nature of twining clockwise around stems of woody plants like a boa constrictor. Other features to distinguish one plant from another are leaf shape, flowering time, flower color, fruit and fruit color, thorns and barbs. Familiarize yourself with the smell of a broken twig. Smell can be used to identify a number of species both invasive and native. The color of the pith or inner wood can be diagnostic of some species, but unfortunately this often just confirms the identification after the stem is cut. The color variations can range from bright yellow, dull orange, light green to off white or bright white. Familiarize yourself with the shape, color and pattern of buds during the dormant season. Also remember that habitat plays a significant role in what invasive species will be present at any one location.
After you have learned how to identify invasive plants the next step is getting out in nature and scouting. It is vitally important to get off the beaten path and look for invasives in out of the way places. People are conditioned to follow marked trails and take the path of least resistance. The barberry I pulled was growing next to the trail but if it had been a few more yards off the trail, most likely I would have walked right by without noticing. Many invasive plants are spread by birds. Their travels can deposit seeds almost anywhere. To protect an area and discover new infestations when they first get established, it is necessary to explore and investigate every part of an area. When scouting look for anything that stands out from the familiar, like a plant you have never noticed before. That plant could be a new invasive or it could just be a native plant that you have never learned to recognize. Key it out in a field guide.
There are numerous personal benefits to gain from scouting for invasive plants. You will likely have views of wildlife and visit places that you and most other people have never seen before. It will also motivate you to get more involved and go deeper into nature. This is a great way to observe and discover all types of interesting things that other people miss by following the beaten path.
Once you have discovered an invasive plant or infestation the next logical step is to do something about it. A large part of the problem with invasive plants is that no one is taking any steps to reverse their impact. You can report it; but who do you report it too? or you can deal with it yourself. Invasives on state land, park land and public land could be reported to the responsible agency. Even if the agency is informed of the problem it is most likely they have no money, staff or motivation to do anything about the problem. You can quickly deal with a few small plants by pulling. Making this small effort will have prevented an infestation from getting started. Larger infestations create a dilemma because of the additional time and effort involved. You can ignore it, report it with the likely result of no action, or you can report it and volunteer to help control the problem. The last option is the best for getting the desired results, but be prepared to navigate the bureaucratic hurdles of getting permission and dealing with liability issues. A small price to pay to protect something of value to you and others.
Many people use nature for various outdoor recreation activities. They range from simply taking a walk and enjoying the beauty and serenity of nature to running, biking, bird watching and nature photography. But not one of these activities gives anything back to nature. You can change that if you learn how to identify invasive plants and you have the ability to bend over and yank a plant out of the ground. You can then join the ranks of a select group of people who are taking action to protect the natural areas we all love and enjoy.
this page updated Feb 10, 2010