We all have at least one plant in our garden that threatens to take over. It spreads out like a carpet or pops up in random places all over the garden, and no matter how much time we dedicate to pulling it up, it still persists. In addition to how to get rid of it, we should be asking ourselves, Is this plant invasive? Is it spreading into wild areas and choking out native plants?
What is an invasive plant, anyway? This invasive plants guide provides a definition of invasive plants, explains what makes a species invasive, discusses the negative impacts of invasive plants, and offers suggestions for how to get rid of invasive plants. Scroll to the bottom to find a list of links to articles on invasive plants by state, so you can learn which plants are invasive in your area.
Invasive plants in my state (VA)
Invasive Plants Guide
What is an invasive plant species?
An invasive plant, according to Invasive.org, is a nonnative plant that causes or will likely cause harm to the environment, economic interests, or human health. A plant is labeled “invasive” when it becomes overly aggressive, growing and reproducing rapidly and significantly disturbing the area around it.
Not all exotic species are invasive. But while only a small percentage of nonnative species eventually become invasive, it is difficult to predict whether a species will become invasive when it is first introduced. Those that do earn the “invasive” label wreak havoc in many ways and are difficult to remove.
Why are invasive plants bad?
In the garden, you likely have observed an exceptionally aggressive plant take over a bed, possibly outcompeting other plants for space and resources. Where you once had a nice variety, you now have a dense population of one plant, perhaps peppered with a few sickly specimens of other species struggling to hang in there. When you try digging it out, you find it nearly impossible to remove every piece of living root, or it reseeds so readily that it pops back every year despite your best efforts.
You can begin to see why invasive plants are such a problem in the wild. When introduced to a new area, invasive plants lack the competitors, parasites, diseases, etc. that keep them in check in their natural habitat. As a result, these plants grow and spread unchecked, outcompeting and displacing native species. A once diverse patch of wildflowers becomes a carpet of a single invasive plant species.
Not only do invasive plants cause environmental harm, but they can also negatively impact agricultural crops, aquatic environments (and thus the fishing industry), and even human-made structures. Some invasive plants are toxic to livestock or people.
Threats to native wildlife
When an invasive plant species takes over an area, it outcompetes the native plants that provide food and habitat for native wildlife. It might even cause harm more directly by disrupting vital functions of the ecosystem like nutrient cycling, water flow, and soil decomposition.
Some invasive plants are toxic to wildlife, but since the plants are not native, the animals do not know they should avoid eating those plants.
How invasive species spread
Many invasive plant species are introduced intentionally, such as for ornamental or agricultural purposes. The people who initially introduce them do not realize that the plants will become invasive, but the plants eventually escape cultivation and spread in the wild. Other species may be introduced accidentally, such as when seeds “hitchhike” in freight or even on travelers’ clothing.
Depending on the type of plant, invasive plants spread in different ways. Some spread via rhizomes, and others through airborne seeds.
Birds eat the berries of fruiting invasive plants and deposit the seeds miles away. People, too, spread invasive plants, whether knowingly or not.
Some invasive species are still sold as ornamental garden plants, and well-intentioned gardeners thus plant a noxious weed in their garden.
What can gardeners do in curbing the spread?
As gardeners, we have the privilege and responsibility to steward plants, both native and introduced. While we thrill in watching an exotic plant thrive in our garden, we must take care that our hobby does not harm the world around us. How can we enjoy gardening without guilt? First, do no harm:
1. Avoid planting invasive species
When considering introducing a new plant to your garden, whether through a purchase or through cuttings or seeds from a friend, do a bit of research first. A quick search online will reveal whether the plant in question is considered invasive in your region. To make things even simpler, bookmark a list of invasive species in your state, such as the ones listed below or the handy map provided by the University of Georgia’s Center for Invasive Species and Ecosystem Health.
2. Remove invasive plants
This action is a bit more involved but hugely important. If you haven’t already, make a list of all the plants in your garden, then look up each one to see if it is considered invasive in your area. Alternatively, you might read through a list of invasive plants in your state and see if you have any of them in your garden. This might be a good activity for a rainy day or during the winter.
If you discover that you do have invasive plants, take steps to remove them. Depending on the specific plant, you might pull or dig it up or cut it down and paint the stump with herbicide. Particularly stubborn species can require multiple purgings before they finally stop popping up in your garden.
3. Choose native plants
While many introduced plants can be safely planted in your garden without aggressively spreading, the best options are native plants. Plants endemic to your region are well adapted to your growing conditions and thus will thrive in your garden with little care. They also provide food and habitat for native pollinators and other wildlife.
If you have discovered that a beloved plant is invasive, consider its qualities that you most appreciate and look for a similar native replacement. For example, American bittersweet might replace nandina with its crimson berries, or American wisteria the fragrant flowers and vining habit of Japanese wisteria.
Invasive plant disposal
A quick note on disposing of invasive plants that you remove from the garden: It is important to dispose of invasive plants properly, as doing so incorrectly can result in the plants spreading and undoing all of your hard work. Different species will have different removal and disposal methods, so make sure to do your research.
In general, though, most invasive plants should be burned or securely bagged and taken to the landfill. Those that only spread through seed may be composted if they are removed before they flower.
Invasive Plants by State
Which plants are invasive in your state? Find out with one of our handy lists below ( we will be adding these slowly over the next few weeks)!
From alligatorweed to tallowtree, Alabama has been infested with some 380 invasive plants. Learn about the 14 worst invasive plants in the state, how to control each of them, and what to
grow instead.
Learn about invasive plants in Alaska and help protect the incredible biological diversity of "The Last Frontier" by planting beautiful natives instead.
Choose native over invasive plants to support the wonderful ecosystems in Arizona. With so many beautiful options to choose from, it's easy to be a native plant steward in this incredible
desert state.
Rather than despair over the numerous invasive plants invading Arkansas, focus on the beauty of the many native plants the state has to offer. If you have one of these invasive plants in your garden, replace it with a spectacular alternative!
Nearly 200 nonnative plants cause havoc in California ecosystems. Discover 16 of the worst offenders, some of which might be hiding in your backyard, as well as a host of beautiful native plants to nurture instead.
As a gardener and plant steward, you can help fight invasive plants in Colorado by replacing them with some of the many beautiful plants native to your state.
With 97 invasive plants in Connecticut alone, it's easy to despair over the situation. But don't fret: learn how to identify and remove some of the worst invasive plants in your state, and fill your garden with native plants instead!
Learn to identify 11 of the 37 invasive plants recently prohibited in Delaware, and discover twice as many beautiful natives to grow instead!
More than 160 invasive plants threaten Florida's native habitats. Learn about some of the worst and take
steps to fight these aggressive weeds in your own garden, replacing them with beautiful native plants.
Help protect the biodiversity of Georgia by learning to identify and properly control some of the worst invasive plants in the state and replacing them with native alternatives.
Help protect Hawaii's unique biodiversity by learning how to identify and control some of the worst invasive plants in the state, as well as which native plants to grow instead.
Help curb the spread of noxious weeds in Idaho by learning how to identify invasive plants in your outdoor space, and which native plants to replace them with
The Illinois Exotic Weed Act currently regulates 26 invasive plants in the state. Learn how to identify and
control each of these species (grouped by genus), and plant similar native plants in your garden instead.
While invasive plants make up a small percentage of plants in Indiana, they create a disproportionately large amount of havoc. Learn about some of the most common invasive garden plants in Indiana, so you can help prevent any in your landscape from spreading and causing damage.
Learn how to identify and remove some of the worst invasive plants that threaten Iowa's ecosystems. In their place, you can grow and nurture plants endemic to your area.
With more than 2,200 native plant species in the state, there's a lot to love about the flora of Kansas. Protect the biodiversity of the prairie by learning how to identify and control invasive plants that threaten native ecosystems.
Take the first step in fighting Kentucky's 145 invasive plant species by learning how to identify and control
11 of the worst invasive plants in the state. As an added bonus, this list includes 22 alternative native plants to grow instead!
With its abundant sunshine, warm climate, and plentiful rain, Louisiana, unfortunately, provides favorable growing conditions for invasive plants. Learn about nine of these noxious weeds and how you can help control them, as well as 18 native species to grow instead.
Help protect the 1,500 native plants of Maine by learning to identify and control some of the worst invasive plants that threaten the diverse habitats of this state.
Coming soon
Invasive plants in Maryland
Invasive plants in Massachusetts
Invasive plants in Michigan
Invasive plants in Minnesota
Invasive plants in Mississippi
Invasive plants in Missouri
Invasive plants in Montana
Invasive plants in Nebraska
Invasive plants in Nevada
Invasive plants in New Hampshire
Invasive plants in New Jersey
Invasive plants in New Mexico
Invasive plants in New York
Invasive plants in North Carolina
Invasive plants in North Dakota
Invasive plants in Ohio
Invasive plants in Oklahoma
Invasive plants in Oregon
Invasive plants in Pennsylvania
Invasive plants in Rhode Island
Invasive plants in South Carolina
Invasive plants in South Dakota
Invasive plants in Tennessee
Invasive plants in Texas
Invasive plants in Utah
Invasive plants in Vermont
Invasive plants in Virginia
Invasive plants in Washington
Invasive plants in West Virginia
Invasive plants in Wisconsin
Invasive plants in Wyoming
Invasive plants are a major problem, posing major threats to native wildlife and ecosystems. But knowledge is power, and the first step toward eradicating noxious weeds is educating yourself and others. Learn about invasive plants in your state, identify any in your garden, and finally, take action to remove and replace invasive species with native plants.
11 Of The Worst Invasive Plants In Maine (And 22 Natives To Plant Instead)
Saturday 31st of December 2022
[…] plants. Unfortunately, these varied habitats also provide ideal conditions for a wide range of non-native invasive species. The Maine Department of Agriculture, Conservation, and Forestry lists 125 invasive plants in Maine […]
9 Worst Invasive Plants In Louisiana (And 18 Natives To Plant Instead)
Thursday 22nd of December 2022
[…] warm climate, plentiful rain, and abundant sunshine make the state, unfortunately, welcoming to invasive plant species. With such favorable growing conditions and a lack of natural controls (i.e., diseases, pests, […]
11 Of The Worst Invasive Plants In Kentucky (And 22 Natives To Plant Instead)
Friday 16th of December 2022
[…] out of 145 may feel like a drop in a bucket, but you’ve just taken a great first step in fighting invasive plants in Kentucky by learning about some of the worst offenders. Now you can recognize these noxious […]
11 Worst Invasive Plants In Kansas (And 22 Natives To Plant Instead)
Tuesday 22nd of November 2022
[…] plants makes them difficult to eradicate, we can still take effective measures to control these noxious weeds. We can even take it one step further, planting and nurturing native plants in their place, […]
9 Worst Invasive Plants In Iowa (And 18 Natives To Plant Instead)
Saturday 5th of November 2022
[…] Invasive plants pose a significant challenge to Iowa’s ecosystems. These noxious weeds threaten prairies, forests, and even aquatic environments, impacting the health of native plants and animals. While humans often introduce invasive species, whether accidentally or intentionally, changing climates sometimes allow plants to spread naturally from their native range to a location where they lack controls to their growth. However they arrive, invasive plants in Iowa — and elsewhere — spread aggressively and outcompete native plants, causing havoc throughout the ecosystem. […]