If you are a gardener, either casual or serious, then you know the activity is really a sport – sometimes a blood sport – as you attempt to rid your well-ordered patches of invasive plants.
Some of these green things are evil invaders brought over during the 1700s when, apparently, settlers couldn’t stand the thought of living without their European-born plants. Hundreds of years later, we are ripping them out of the ground, tearing our hands on their thorns only to find ourselves repeating the process, growing season after growing season.
To help us better understand the siege our gardens are under, on June 9 the Sippican Lands Trust in collaboration with the Marion Garden Group and Marion Women’s Club hosted a presentation by Frederick Sechler, Jr. of the New England Wild Flower Society whose topic was invasive plants.
One of the more interesting bits of information Sechler imparted was that not all invasive plant species are really invaders.
An audience member asked if he could identify specimens she held out in a plastic bag, plants that she had been pulling from her gardens continuously year after year. Of the three sprigs Sechler studied, all were “native species.” The lady was aghast. The plants were the Virginia creeper, blackberry, and green briar.
Sechler said a gardener might not want those plants in their yards, but banished the notion that all invasive or aggressive varieties came from someplace else. Not to put too fine a point on that comment, he said, “Even poison ivy is native.”
Of those plants that are, in fact, foreign born and taking up residence in New England, Sechler identified Japanese knotweed (looks like bamboo), common reeds known as phragmites, Japanese barberry, water chestnut, and, the worst of the worst, bittersweet and Norway maples.
Sechler said that while some invasive species respond well to chemical eradication, some do not, such as bittersweet. And Japanese knotweed takes a combination of aggressive chemical treatments and removal over years, “And it still might not work well.”
Sechler said that oftentimes local permits are required before applying chemical treatments, especially for larger areas, and he cautioned reticent use of such products.
Sechler also noted that many invasive non-native plants like disturbed soils and thus construction and other landscape changes may result in good environments for unwanted plants.
So, what exactly is a non-native invasive plant?
The criteria are: 1) non-native to New England, 2) spreads rapidly, 3) displaces native flora, and 4) persists in natural landscapes.
IPANE, the Invasive Plant Atlas of New England, points out that many invasive plants have been in the environment since the 1700s and are considered non-native and also indigenous. It reports that of the 4,000 indigenous plants originating from that time period, 1,700 are not native to New England.
Movement of the invasive plants includes garden introduction (remember those settlers), accidental transportation (ballast in ships used to relocate said settlers), habitat disturbance (they love soils that have been dug up), birds and other wildlife, and even farm equipment.
Invasives have survived for all those reasons, and the lack of natural predators or pathogens that would control or eliminate their continued presence in New England is why they continue to survive, Sechler said.
To learn more about how you can identify and control invasive plants – both native and non-native – on your property, visit www.newenglandwild.org or contact the Sippican Lands Trust at 508-748-3080 for other resources.
By Marilou Newell