How to Remove Invasive Plants from Commercial Properties (And Prevent Their Return)

Sometimes, nature tries to take over.

Invasive plants are an increasing problem in Maryland, Virginia, and DC, taking over areas of native trees and plants and slowly killing them.

What are invasive plants? How do you control them? 

An invasive plant is a species that’s become a pest, growing aggressively, spreading and displacing other plants. If they’re not physically removed, they can take over, killing the beneficial plants you want to thrive on your property. 

Let’s learn more about invasive plants on commercial properties, including:

First, What’s An Invasive Plant?

What Are Common Invasive Plant Species? 

Are These Common Invasive Plants On Your Property? 

How to Remove Invasive Plants

Controlling Invasive Plants: How to Keep Them From Coming Back?

Removing Invasive Plants on Commercial Properties

First, What’s An Invasive Plant?

An invasive plant is a species that’s become a pest, growing aggressively, spreading and displacing other plants.

Often, they’re not native, making their way here from other countries. But native plants can be invasive, too.

“These plants are very, very hardy,” says Brad Butler, corporate manager at Level Green Landscaping. “The reason they made it here from Asia or Europe or Africa is because that seed made it across the sea and is thriving here. They’re very hard to kill and very hard to stop.”

Many invasive plants in Maryland, Virginia, and DC are vines.

“They grow up through the trees and cover the canopy,” Butler says. "The tree dies and the vine survives.”

Chances are, you see them every day

“You can’t drive down any highway in this area and not see vines overtaking the trees,” Butler says.

What Are Common Invasive Plant Species? 

There are a host of invasive plants in Maryland, Virginia, and DC but the ones that are most troublesome include:

• Autumn olive
• Asian privet
• Kudzu
• Native wild grape
• Multiflora rose
• English ivy
• Cheatgrass
• Tree of Heaven 

Some new invasive plants have been showing up in Maryland and Virginia, Butler says, including cheatgrass.

This aggressive grass germinates early in the spring and grows fast, quickly outcompeting native plants for water and nutrients. 

To make matters worse, cheatgrass dries out much earlier than native vegetation, creating a super flammable fuel source that increases the risk of wildfires. 

“It’s a big factor in the wildfires out West, and we’re seeing it in Maryland now,” Butler says. “It quickly becomes tinder.”

Tree of Heaven is another increasing problem.

“A couple years ago we removed some from St. Mary’s State Park, and it was the only place I’d seen it,” Butler says. “Now I see it everywhere. It’s stealing areas and taking them over before native plants can fill in.”

This tree is double trouble — it’s the preferred host tree of the spotted lanternfly, a destructive invasive insect that devours and destroys plants and trees. 

That makes Tree of Heaven among the most troublesome invasive plants on commercial properties and well worth the trouble to remove. 

Are These Common Invasive Plants On Your Property? 

Some invasive plants might surprise you. You might have them on your property, in your yard or even see them routinely at garden centers.

“English ivy is probably the most recognized invasive plant,” Butler says. “For years landscaping companies planted it to cover brick walls. People thought, instead of this ugly brick wall, let’s cover it with this green living thing.”

But it soon got out of control.

As it climbs trees, English ivy can suffocate them by blocking sunlight, and the weight of the vines can cause branches to break or even topple the entire tree. 

It also damages walls, fences, and other structures as it climbs and clings. 

“The roots get in-between the grout of brick walls, finding their way into any crack,” Butler says. “Over the last three or four years we’ve done some pretty extensive removal of it in the DC area.” 

Barberry is another common plant most people don’t realize is invasive, Butler says. 

“Nurseries still sell barberry because people love it,” Butler says. “Wisteria, too, is hugely popular, sold front and center at garden centers, especially when it’s in bloom.

“You can see wisteria in the woods,” he says. “It will grow right up over an oak tree and the oak tree dies. That little wisteria will take down a 150-foot tall tree.

“It’s easy to say, ‘Well, I’ll just plant it in my yard —  it won’t make it into the woods,’” Butler says. “But birds and wind carry the seeds.”

How to Remove Invasive Plants

Removing invasive plants is critical, but it’s painstaking work. 

The first step is to cut away the invasive vines at about shoulder height, Butler says.

In many cases, the growth is so dense that crews use mechanical shears. But removing invasive plants can be delicate work, too, when invasive plants are entwined with beneficial native plants that crews want to save.

That means painstaking work with hand pruners.  

After the cutting, the bottom part of the plants are treated with herbicides. Sometimes crews mix a dye in with the herbicide so they can see exactly what’s been treated.

The cuttings are removed and often chipped.

“Generally removing invasive plants is a multi-year plan,” Butler says. “You have to go back and spray for up to five years to be sure you catch anything that’s rejuvenated. You can’t just walk away and it’s taken care of.”

Each invasive plant drops hundreds, if not thousands, of seeds, Butler says. The seeds are carried away by birds and wind to reseed.

“It’s a constant battle,” he says.

When St. Mary’s County received federal grant money several years ago to remove the invasive plants encroaching on Myrtle Point State Park, they called on Level Green to tackle the project.

Level Green crews worked diligently there for two years in a row removing the tenacious vines, while battling ticks, mosquitoes, and snakes in the thick growth. 

“I was there in late summer this year and the areas we did still looked in pretty good shape,” Butler says. 

Invasive plants in Maryland, Virginia, and DC can affect precious waterfront areas, too, Butler says. 

Invasive plants form a dense mat on the surface of the water, shading the underwater plants so they don’t get enough sunlight. That creates low oxygen levels in the water, which can kill fish. 

Removing Invasive Plants from The Columbia Association

Level Green crews also worked to remove a persistent invasive species at the Columbia Association, a non-profit corporation that maintains nearly 3,600 acres of recreational open space for residents of Columbia, Md. 

The culprit? Phragmites, also known as common reed, a vigorous grower that outcompetes native species and alters wetland ecosystems. Its aggressive growth creates dense stands that can block water flow and take over habitat for fish, birds, and other wildlife. 

“Over the past three years, we’ve gone in every winter and cut it all down, pulled what we could, and hauled out all the debris,” says Jesse Ware, the Level
Green account manager for the property. The Association followed that with an herbicide treatment to slow regrowth, Ware says.

That combination has reduced the phragmites infestation by at least 60 percent, Ware says. 

Controlling Invasive Plants: How to Keep Them From Coming Back?

The best way to keep invasive plants from coming back after removal is to plant native plants to grow in their place, Butler says.

Native plants have grown and thrived in a particular area naturally, without being introduced by humans. That means they’re well-adapted to the local climate and conditions, and can easily thrive. 

“But it’s a battle,” Butler says. “Invasive plants can actually change the soil chemistry to make it easier for invasives to grow and harder for native plants to take hold.”

When that happens, he says, the soil has to be amended to make it more hospitable for native plants to thrive. 

Removing Invasive Plants on Commercial Properties

On a typical commercial property that has routine maintenance, invasive plants are less of an issue, Butler says. But some properties own borders of woods that don’t get maintained, and that's where invasive plants become a problem.

In pine and evergreen forests, little light penetrates and the thick natural mulch of pine needles keeps invasive plants from sprouting. But deciduous woods are vulnerable.

“Clients who pay for invasive plant removal know they’re losing trees,” Butler says. “They know they’ll lose their woods to invasive plants and they won’t have that border anymore.”

The hard work of invasive plant removal is worth it, Butler says. “Years down the road when we see the native plants take back over again, it will be rewarding. We’re promoting healthy, native forest land.”

Attack Invasive Plants With Level Green

Here at Level Green Landscaping, we have the knowledge, skill, tools and patience required to tackle invasive plants in Maryland, Virginia and DC. 

And we love our native forests — we’re proud to help protect them.

If you’re not already a Level Green Landscaping client, we’d love to add you to our growing list of happy customers. Our focus is on commercial properties like offices, mixed-use sites, HOAs, municipalities and institutions in Maryland, Washington DC and parts of Virginia.

Contact us at 202-544-0968. You can also request a free consultation online to meet with us one-on-one.

We’d love to hear from you.

Image sources: kudzu, english ivy, english ivy on tree and shrubs