Gardeners talk a lot about planting natives and eradicating invasive plant species. That’s because they are a bigger deal than most of us realize, and yes, each of us can help with this massive by using good measures in our home gardens. First, the definition of invasive plants. .

Habitat loss and invasive plants are the leading cause of native biodiversity loss. Invasive plant species spread quickly and can displace native plants, prevent native plant growth, and create monocultures. A healthy plant community has a variety of herbs, shrubs, and trees. Invasive plants cause biological pollution by reducing plant species diversity. Changes in plant community diversity lessen the quality and quantity of fish and wildlife habitat. City of Portland, Environmental Services

The invasive plant species will win the real estate battle and either kill the trees, shrubs, and flowers or limit their ability to grow and repopulate, thus reducing the native population of plants that contribute significantly to the ec0-system.

Here are five essential reasons why invasives are so harmful to our environment.

Water Quality

When invasive plants are used as a groundcover by a homeowner (think ivy, periwinkle, or clematis) or have become the groundcover through seeding (think kudzu, honeysuckle), the root structure is shallow and unable to “hold” the soil like a more diverse planting system with trees and shrubs would. The lack of a fibrous root system results in flooding and stream sediment, reducing water quality.

Invasive plants such as Japanese knotweed and multiflora rose impede the growth of native seedlings that would naturally occur near streambeds. This can reduce shade trees and increase the temperatures of the stream. One thing always affects the other. The ripple effect of invasive species and their ability to establish dominance quickly may seem only to affect the flora and not the fauna, but the opposite is true. It affects all of life’s eco-system. The temperature rise, lack of shady areas, and stream sediment affect water quality, fish, and wildlife.

Fish and Wildlife Habitat

As noted above, stream life is directly affected by the erosion of stream banks and the water temperature increase. Non-stream wildlife is also affected. Invasive plants outcompete native plants, the food and habitat source for native wildlife species. Invasive species are one of the primary threats to native wildlife. An estimated 42% of endangered species are at risk due to invasive plants. Invasive Species National Wildlife Federation

When plant life is diverse, there is a greater food and habitat supply for more animal species and larger populations. Invasive plants have monoculture habits, meaning they completely dominate the landscape, eradicating all other plant species. This creates problems for all native animal species, not just a select few. Think monarch butterflies, eradicating habitat and food supply.

The dense covering of Invasive plants prevents seedling establishment and stunts the growth of established trees. Sunlight cannot reach the seedlings or allow photosynthesis on mature trees. Dense ivy or clematis in the tree canopy can weigh down trees, making them more susceptible to blowdowns.

Fire Risk

Monocultures of invasive plants create the perfect storm for wildfires–frequency and intensity.  As invasive plants climb trees (think of ivy or kudzu), fires can easily reach the tree canopies. These fires are more difficult to control.


Invasive plants aren’t just a problem that affects our forests and rural areas. The cost of invasive plants affects all of us. The management of invasive plants is estimated at 21 billion a year with most of those costs directed at our agriculture economy. Cost of Invasive Species

Written by Cinthia Milner, Landscape Consultant and blog writer. 

B.B.Barns serves Western North Carolina, upstate South Carolina, and Tennessee.