What is an invasive plant?
An invasive plant is a non-native plant that spreads aggressively, crowding out native plants and changing how the landscape works. Invasive plants don’t just take up space. They leave wildlife with less food and fewer places to live.
Invasive vs. non-native: what’s the difference?
Not all non-native plants are invasive. To be invasive, a plant needs three things:
- It has to survive in the local climate,
- Reproduce quickly, and
- Spread aggressively without natural controls
Petunias are a good example of a non-native that’s not invasive. They’re native to South America, but nurseries sell them across North America every spring. A gardener in Connecticut can plant petunias without worrying they’ll take over New England because the non-native plant can’t survive frost. It dies every winter.
Invasive plants, on the other hand, don’t just survive: they thrive. They spread faster than native plants, and nothing keeps them in check. That’s when a non-native becomes a problem.
What makes a plant go from “new arrival” to “invasive problem”?
When you move a plant to a new place, it often leaves behind the insects, diseases, and plant competitors that kept it in balance back home. Think of it like this: in its native habitat, a plant might get eaten by specific caterpillars, infected by fungi, or outcompeted by neighboring plants. Those pressures keep it under control.
But in a new environment? All those controls disappear. The plant can grow unchecked.
Here’s what typically happens when an invasive plant finds itself in a new place with no natural enemies:
It reproduces like crazy.
Many invasive plants produce thousands of seeds per plant, or spread aggressively underground through roots. English ivy does both—seeds spread by birds, vines creep across the ground.
It grabs resources first.
Invasive plants often leaf out earlier in spring, grow taller, or handle a wider range of conditions than native plants. They get the sunlight, water, and nutrients before natives even wake up.
Some even poison the competition.
Plants like garlic mustard release chemicals into the soil that make it harder for native plants to grow. It’s chemical warfare at the root level.
It thrives because the climate matches.
Invasive plants that really take off are usually from regions with similar climates to where they land.
- Kudzu from Japan found the Southeast U.S. to be a perfect match.
- English ivy from Europe loves the Mid-Atlantic and Pacific Northwest.
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The landscape looks green, but it’s a desert for birds and insects.
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Why invasive plants matter beyond “taking over”
This is where it gets interesting (and a little depressing): invasive plants don’t just crowd out natives. They break food webs.
Native insects evolved to eat specific native plants. When invasive plants dominate a landscape, those insects lose their food source and disappear. And when insects disappear, so do the birds, frogs, and other animals that eat them.
A yard carpeted in English ivy supports a fraction of the insect life that a yard with native groundcovers would. Fewer insects means fewer birds. The landscape looks green, but it’s a desert for birds and insects.
Some other ways invasives mess things up:
- They can change soil chemistry (autumn olive adds nitrogen in ways that help other invasives)
- They alter water flow and erosion patterns
- They can increase wildfire risk (looking at you, cheatgrass)
- They turn diverse plant communities into monocultures
The bottom line: invasive plants drastically simplify landscapes, and simple landscapes can’t support much life.
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You'd think all this scientific data would lead to strong regulations banning the sale of invasive plants. It doesn't.
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Who decides what’s invasive?
Science comes first when it comes to invasives. Botanists and ecologists study which plants are spreading and causing harm. Organizations like state natural heritage programs, university extension offices, and the Invasive Plant Atlas track the data and provide lists of what to look out for.
Sadly, few laws exist to stop invasive plant spread
You’d think all this scientific data would lead to strong regulations banning the sale of invasive plants. It doesn’t.
Most states have weak or nonexistent laws about invasives. A handful ban the sale of specific species. Others just publish educational materials and hope nurseries pay attention. Regulation is wildly inconsistent: a plant that’s illegal to sell in one state is sitting in garden centers across the border.
Even worse: enforcement is nearly nonexistent. I still see English ivy, burning bush, and Japanese barberry for sale at nurseries, despite being on invasive species lists.
The result? Most of the responsibility falls on nurseries to stock responsibly (many don’t), and on homeowners and land managers to remove what’s already spreading. The burden of fixing this problem lands on residents, not on the industries or governments that could actually stop it at the source.
What you can do:
- Contact nurseries that sell invasives and ask them to stop (polite emails with links to state invasive lists work surprisingly well)
- Support local and state legislation that bans invasive plant sales
- Talk to your native plant society or land conservancy about advocacy efforts
- Remove invasives from your own property and encourage neighbors to do the same
We can’t wait for laws that may never come. In our lifetimes, the work is ours.
Common invasive plants
Invasive plants vary by region, but here are a few of the worst offenders you’re likely to encounter:
- Kudzu blankets the Southeast, growing up to a foot per day and smothering entire forests.
- English ivy climbs trees and forms dense ground mats across much of the U.S.
- Garlic mustard carpets forest floors in the East and Midwest, releasing chemicals that harm native wildflowers.
- Japanese barberry forms thickets that crowd out natives and create cover for Lyme disease-carrying ticks.
For a longer list with photos and removal tips, check out our guide to Common Invasive Species.
How to remove invasive plants
The best method? Pull them out by hand or dig them up, roots and all.
Manual removal works best for:
- Young plants before they’re established
- Shallow-rooted species like garlic mustard
- Vines like English ivy (though it takes years of persistence)
Tips for success:
- Pull after rain when soil is soft
- Get the entire root system whenever possible
- Remove plants before they go to seed
- Work on it consistently, a little every season adds up
You can’t remove them all (and that’s okay)
Here’s the reality: invasive plants have been spreading for decades or centuries. Their seeds travel via wind, water, and birds.
We cannot eradicate them from the landscape.
But that doesn’t mean our work doesn’t matter.
Every invasive you remove creates space for natives to grow. Every yard that shifts from English ivy to native groundcovers supports more insects and birds. The impact is incremental, but it’s real.
Make it manageable:
- Pick 3-5 invasives to focus on. You can’t fight them all. Choose the ones most common in your area.
- Learn what they look like. Get good at spotting them in different seasons and life stages.
- Remove them when you see them. Even 15 minutes a week makes a difference.
- Replace with natives. Don’t leave bare soil; plant native alternatives to fill the space. Check out our Native Plant Library for ideas.
- Talk to neighbors. Change happens when communities work together. Maybe we can make English ivy removal parties a thing?
- Keep at it. This is ongoing stewardship, not a one-time project.
A story of vigilance
English ivy is one of the invasive plants I’ve decided to focus on removing. It is everywhere in my suburban Pennsylvania community. I can understand why landscapers and homeowners chose it: it quickly covers large areas, is evergreen, and requires minimal work. But it spreads so quickly, it can overtake a yard and start climbing up trees in just a few years.
What I’ve done at home
Every spring and fall, I spend ~15 hours removing English ivy from my backyard. It was planted by the previous homeowners 20 years ago and had overtaken the property (and some of the trees!) when we moved in. The first year, we filled 17 CONTRACTOR BAGS with ivy. In the following years, it has been two bags. Perhaps in another 15 years, we will have removed it all (but I doubt it.)
What I’ve done in my community
English ivy is sadly all over my neighborhood. I have gotten to know some neighbors and mentioned why (and how) we removed the ivy. Three other neighbors have removed the ivy from their properties since. But it’s still seemingly everywhere.
I sometimes see English ivy sold at local plant nurseries. I’ve found success writing a thoughtful, researched email to the business with links to trusted, government sources, asking for them to no longer carry invasive species.
The bigger picture
You can’t fix everything. But you can make your yard better. And when enough people do that, landscapes change.
Native plants are resilient. When you remove invasives and plant natives, birds come back. Insects return. The soil heals. You’re not just pulling weeds. You’re making room for the plants and animals that belong here.
That matters.
Resources
Find your state’s invasive species list:
- Invasive Plant Atlas of the United States (IPANE)
- USDA Plants Database – Invasive and Noxious Plants
- Google your state + invasive species list
Learn more about invasives:
- National Invasive Species Information Center
- The Nature Conservancy – Invasive Species
- Google to find your local university extension office
What to plant instead: Check out our Native Plant Library to find native alternatives to common invasive plants, or visit our Native Nursery List to find sources near you.
Happy planting (of natives)!
Sources
- Tallamy, Douglas W. Nature’s Best Hope: A New Approach to Conservation that Starts in Your Yard. Portland: Timber Press, 2020.
- Invasive Plant Atlas of the United States. “Invasive Plant Atlas of the United States.” University of Georgia – Center for Invasive Species and Ecosystem Health. Accessed February 15, 2026.
- USDA, NRCS. “Federal Noxious Weed List.” The PLANTS Database. National Plant Data Team, Greensboro, NC. Accessed February 15, 2026.
- National Invasive Species Information Center. “National Invasive Species Information Center.” United States Department of Agriculture. Accessed February 15, 2026.
- Colautti, Robert I., et al. “Is invasion success explained by the enemy release hypothesis?” Ecology Letters 7, no. 8 (2004): 721-733. https://doi.org/10.1111/j.1461-0248.2004.00616.x
- The Nature Conservancy. “Invasive Species.” Accessed February 15, 2026.
- Williams, Samantha C., and Jeffrey S. Ward. “Influence of Japanese Barberry (Berberis thunbergii DC.) on Nymphal Ixodes scapularis (Acari: Ixodidae) and Other Ixodid Ticks.” Environmental Entomology 39, no. 1 (2010): 299-308.
- Bohn K, Pavlick R, Reu B, Kleidon A. “The strengths of r- and K-selection shape diversity-disturbance relationships.” PLoS One. 2014 Apr 24;9(4):e95659. PMC3998956.
