Invasive Plants

The Massachusetts Invasive Plant Advisory Group (MIPAG) defines invasive plants as “non-native species that have spread into native or minimally managed plant systems in Massachusetts. These plants cause economic or environmental harm by developing self-sustaining populations and becoming dominant and/or disruptive to those systems.”

Invasive plants have all been imported by people, either intentionally or accidentally, from other parts of the globe. In their home range, invasive plants aren’t invasive – there are natural mechanisms, such as herbivores, diseases and pests, and competing plants, that keep their populations in balance. But when introduced to our area, invasive plants don’t face those same pressures, and they can grow and spread unchecked.

Learn about the invasive plant species that may grow in Weston.

A native plant is one that occurs naturally in the place where it evolved. Native plants are part of the balance of nature that has developed over hundreds or thousands of years in a particular region or ecosystem. Only plants found here before European settlement are considered to be native to the United States. Some plants that people considered to be nuisance species, such as poison ivy and greenbriar, are actually native.

Not all non-native plant species are invasive. In fact, 31% of plants in New England are non-native, but 10% are considered invasive.  Invasive species are non-native species that have certain characteristics that allow them to quickly overpopulate, such as:

• Growing and reproducing rapidly
• Leafing out earlier and retaining leaves longer than native species, allowing them to gather more nutrients
• Dispersing prolifically, either by seeds or clonally
• Tolerating a wide range of environmental conditions

Native plants work in natural communities to clean air, water and soil, serve as the base of food chains, provide habitat for wildlife, and do much more.  When invasive species infest a plant community, they outcompete and displace the native species that have evolved to be part of that community. This displacement can cause disruptions throughout the ecosystem. Colonies of invasive species impact food sources for wildlife, change the structure of habitats (such as branch heights for perching and plant density for hiding), and alter the amount of light, water, and space available for other plants. Invasive species can change the soil’s chemistry so that it is unfavorable for other species to grow in for years to come. In some cases, they can even directly harm or poison wildlife.

Invasive plants can directly impact people as well, such as impairing public utility operations, altering water quality, limiting outdoor recreation, and threatening public safety. Oriental bittersweet can pull down power lines, Japanese knotweed can crumble pavement and obscure sight-lines on roadways and corners, and water chestnut can clog the waterways - these are just a few examples. For farming and forestry operations, invasive plant infestations can bring significant economic impacts. Species like giant hogweed can even physically harm people, pets, and livestock.

Read more about what you can do to help control invasive species in Weston.