Invasive Species

A member of the Poppy family, this perennial herb can grow 16-25" tall. The lower part of its stem and leaf stalks are sparsely long-haired. Its flowers are 0.8-1.2" wide and have four yellow petals. Its leaves are alternate, stalked, bladed, and have a bluish-grey underside. It blooms from June-August. This plant is also poisonous and doesn't produce any nectar, only being pollinated by nutrient-hungry insects.

This tree can reach 70 feet in height, grow quickly, and live 30 to 70 years. It has smooth, gray bark with chestnut-brown twigs. Its leaves are large and can be 1-4 feet in length, having 11-25 leaflets. When it blooms in June, the large clusters of flowers it produces are small and yellowish-green ... and can have a very unpleasant, unheavenly odor.

Native to Japan and China and introduced to North America in the 1870s, this plant is a woody, perennial vine that can grow 20 feet or more. The bark has light-colored dots and won't peel. Leaves are alternate and broadly ovate with a heart-shaped base, having 3-5 lobes and toothed margins. The berries are hard and small and can be pale violet, green, or bright blue.

This pesky rose is known for its thorny, multi-stemmed, perennial shrub or climbing vine with arching stems. It can be 5-12 feet tall. The leaves are divided into eleven elliptical, sharply-toothed leaflets, each being up to one inch long. The stems are bright green to reddish, usually with curved thorns. The flowers are showy, fragrant, white-pink, and about one inch across.

This nasty early-germinating winter annual is native to Europe and grows in a rosette in leaves when it is under five inches tall, then sending an inflorescence on the stem that ranges from 2-12". It is a very unpredictable plant when it comes to blooming, and each flower is white with four petals. Pulling the plant offers some control, that is unless the seeds shoot into the ground.

This nasty invasive weed is native to Europe but has spread rapidly across North America. It's a cool-season perennial forb that produces stolons that root at their nodes. They can grow in a wide variety of soil conditions and climates and spread easily, making them hard to stop at first. They're easily identifiable by their white flower and three-leaf clover. Fortunately, hand-pulling is an effective means of removal!

This plant is easily identifiable through its yellow wood, yellow, six-petaled flowers, and three-branched spines at the base of its leafstalks. The fruit it produces is a berry that comes in various colors: red, yellow, blue, purple, or black in particular.

This perennial flower has shiny, dark-green leaves that are kidney-shaped and stalked. Its defining feature is its flowers -- they're glossy, butter-yellow, and appear in March-April, dying back by June. For small clusters of these pesky flowers, hand-pulling is an effective means of removal.

Introduced to the United States in 1866 as a perennial from East Asia, this plant is a multi-stemmed deciduous shrub that matures to a height of five feet and a width of seven feet. The simple, light-green leaves are opposite, doubly serrate, and rough and can grow up to four inches long and one inch wide. In the summer, any flowers this plant has (which are white with four petals) turn into black fruit.

This is a highly invasive herbaceous annual vine that sometimes hitchhikes in the soil of containers from nurseries. In peak growing season, mile-a-minute can grow 6 inches in one day. It can be identified by its distinctive arrow-shaped leaves and prickly stem. The dense foliage of this invasive weed blankets and slowly suffocates native vegetation. To control, pull manually before it develops berries.

Growing 7-9.8 feet tall, this invasive is identifiable through its leaves: they're light green with red or purple flecks, heart or shovel-shaped with a pointed tip, can grow up to 7.9 inches long, and shoot out from nodes in a zig-zag-like pattern. Like bamboo, the plant has visible nodes between its stems, whose crowns emerge from dense clumps. The flowers are creamy-white and grow in panicles up to 3.9" long.

This is a relatively new invasive species in the area, first being reported in New Hampshire in 1916 and New Jersey in 2000. If left to spread, it can create a smothering monoculture. And fortunately, it is edible -- and ready to be foraged! Its best removal method is through hand pulling.

Native to Japan and arriving in the United States in 1806, this invasive species has opposite, simple oval leaves that are 0.3-3.9" long. Most of its flowers are borne in clusters of two, are sweetly scented, and bilaterally symmetrical. There is a high incidence of Lyme Disease next to these trees due to the fruit attracting deer, which brings ticks.

This invasive plant is an upright, deciduous shrub that grows 20-40 feet high and 15-30 feet wide. It has an irregular, spreading, multi-stemmed form. The stems are coarse, thick, and covered with spines and thorns. The leaves are long, dark green, and alternate.

When people think of a weed, this is the defining crop. The stems are slender and hairless, the leaves are lance-shaped or oblong, alternating one another on the stem. They can be found virtually everywhere, but they can also easily be removed.

Despite the name, having these weeds isn't smart in any situation. When they grow, they spread out, creating mats that bar any native plants from getting essential nutrients. That can eventually ruin the soil, making plant growth impossible. When you're on the hunt for invasive species, look for these mats, as well as a purple underbelly on the leaves. You'll be smart for doing so.

You can identify this nuisance of an invasive species through its triangular, heart-shaped leaves with toothed edges and white, four-edged flowers. It was originally brought here in the 1800s from Europe for herbal control and erosion control. Fortunately, though, the plant is indeed edible -- especially when young -- as it adds spice to almost any dish!

This plant is native to central and northern Europe but was spread here by humans. You can easily identify it by its distinct, dark-green leaves, which are hairless above and silvery-white below. But the defining characteristic of a mugwort plant is its sage-like odor -- it can be used as a spice or flavoring agent in dishes, which we at the Jay Heritage Center are well aware of.

This perennial grass is highly variable and robust and can grow 5-10 feet in height. The branches are very flexible and can spread or droop. The leaves are elongated and can be up to three feet long and one inch wide, having a silver-white midrib and tips that are sharp and re-curving. The branches of the fan-shaped, 6-24" long, silvery pink-pale panicle are erect or ascending.

This invasive shrub was introduced into North America in the 1890s. It is differentiated from other berry-producing canes, such as raspberries and blackberries, by the stem's reddish appearance, silvery underleaf surfaces, and bright red berries.

This annual grass can grow to heights of 2-3.5 feet tall and is easily identifiable via its pale green, lance-shaped leaves with silvery stripe hair along the midrib. Those leaves, by the way, can grow up to three inches long. In August through October, the plant blooms, generating flower spikes in pairs. Hand pulling is an effective means of removal.

This weed is sadly relatively difficult to control and is an aggressive perennial that's well suited for most landscape situations. It's characterized by coin-shaped leaves with scalloped edges and square stems, as well as its purple flowers. Because it is in the mint family, there is a distinctive mint odor when cut or crushed. Hand pulling is a method of removal that is certainly therapeutic but mostly ineffective due to how aggressively this plant spreads.

Yes, these trees can grow to be quite beautiful -- and we currently have one growing in the second room of the Gardens. That said, we don't want too many maple trees on the property ... and they reproduce quickly and detract from the native biodiversity. Fortunately, this species is easily recognizable and removable due to its distinct red color, making it stand out.

This invasive tree, native to Europe and Western Asia, is a particularly tiresome one. Their leaves are simple and green, broader than they are high, about 4-7" wide, and have five prominent lobes. One of the easiest ways to identify this plant is seeing white sap upon the removal of a leaf.