Invasive Plants

A before and after photo of the area around Forbes Rock on Culp's Hill where the invasive plant species Japanese Stiltgrass has been removed by park biologists and volunteers.

NPS Photo

Native Plants

***These are All Good*** Native plants are species in a given ecosystem that occur naturally, without human intervention, through natural processes like seed dispersal by wind, water, or animals, or through the establishment of new populations from existing ones. According to the Bureau of Land Management, "Native plant communities create habitat which is necessary for wildlife and essential to sustaining biodiversity and resilient landscapes. As the foundation of healthy functioning ecosystems, native plant communities buffer the impacts of extreme weather events such as severe flooding and prolonged drought."

Non-Native Plants

***These are Good, but some could be Bad*** Non-Native plants are those that have been introduced to an area where it did not naturally exist before. It’s important to note that non-native species are not necessarily considered invasive. Examples of non-native species that are not considered invasive include food crop plants like tomatoes and rice or beautiful flowers like tulips and peonies.

There are two different types of non-native plants: intentional and unintentional.

• Intentional Non-Native Plants: Humans sometimes intentionally introduce plants for agriculture, landscaping, or other purposes, but these plants can sometimes escape and become invasive.
  • Examples of intentional and even cultivated species which became invasive include Tree of Heaven, Kudzu, English Ivy, and Burning Bush.
• Unintentional Non-Native Plants: Plants can hitchhike on vehicles, clothing, packing materials, can be carried in ballast water of ships, or on firewood.
  • Examples: Japanese Honeysuckle, Common Tumbleweed, Purple Loosestrife.

Invasive Species

***These are All Bad*** Invasive species are plants that, once introduced to an environment, it establishes itself, aggressively spreads, causes harm to its immediate environment, and can cause harm to one or all of the following: plant, animal, human, or economic environments. Once an invasive species has established itself, removing it or eradicating it can be very difficult, requiring lots of time, money, and man-hours. Which is why catching invasive species early on is very important.

Early Detection Rapid Response Species Protocol (EDRR)

***Park Biologists to the Rescue!*** Early Detection Rapid Response Species Protocol, or EDRR for short, is a strategy for identifying and responding to new or emerging invasive species (plant, animal, or other organisms) before they become widespread and cause significant harm to ecosystems or human interests.

• Detection: This involves actively monitoring habitats, reporting sightings of potentially invasive species, and potentially using tools like eDNA sampling to detect their presence.
• Rapid Response: Once an invasive species is detected, the protocol outlines swift actions to prevent its establishment and spread, potentially including eradication efforts, containment measures, or other management strategies.

The Top 10 Least Wanted List

***The list below describes our Top 10 Least Wanted List*** Among the many invasive species that our staff have documented at Gettysburg National Military Park (NMP) and Eisenhower National Historic Site (NHS), we’ve identified ten species that have the largest, and worst effects, on the parks and surrounding area. These invasive plant species are categorized as both well-established and those recently discovered. Regardless of their time on and around the parks, their impacts are significant.

Each entry includes the species, a photo, and its impact on the ecosystem. Additionally, we describe the efforts we use to combat the spread of these invasive species. Finally, we’ll go over how our visitors can help identify, report, and aid in our efforts to contest the spread of these harmful plants.

 

The Top 10 Least Wanted List: Shrubs

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  Japanese Barberry

  The dense Barberry growth creates a microclimate that is ideal for black-legged ticks (deer ticks), which are a source of Lyme disease.

• 

  Multiflora Rose

  The Multiflora Rose is commonly found throughout woodlands and fields and can cause severe skin and eye irritation in cattle.

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  Wineberry buds

  Vigorous growth prevents native saplings from initial development as well as regeneration after a disturbance such as a severe storm.

 

The Top 10 Least Wanted List: Herbs

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  Invasive Garlic Mustard

  Garlic Mustard is a toxic decoy plant that misleads some butterfly species into laying their eggs on it when no food source exists.

• 

  Japanese Stiltgrass

  Japanese Stiltgrass alters soil chemistry creating an inhospitable environment for native plant species.

• 

  Wavyleaf Basketgrass

  Wavyleaf Basketgrass is an aggressive invasive plant which grows in semi-shaded areas. It severely diminishes native plant and tree growth.

 

The Top 10 Least Wanted List: Trees

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  Callery Pear

  The Callery Pear blossom has an offensive smell. Its dense root growth prevents native species from growing.

• 

  Tree of Heaven

  An aggressively invasive plan which sprouts new sapling when cut and is the favorite host plant for the Spotted Lantern Fly.

 

The Top 10 Least Wanted List: Vines

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  Chinese Yam

  Chinese Yam vines can damage to trees by blocking nutrients and weighing them down, breaking off branches.

• 

  Japanese Honeysuckle

  The dense mats of Japanese Honeysuckle destroy native ground species and prevent new growth.

 

What Can You Do

As a devoted visitor to Gettysburg National Military Park and Eisenhower National Historic Site, you can see the direct impact invasive species has on your parks. During the warm weather months, we host a series of Volunteer Work Days. Sign up for one or all of these to lend a hand! You can aid our staff to combat these invading species and perhaps slow or halt their march across our fields, our hills, our stone walls, our fences, or even around our monuments.

Click on the link below to learn more!

 

Learn How You Can Volunteer! Help Us Control Invasive Plants!

 

Volunteer Contributions

Shrubs

• Japanese Barberry: Visitors can assist park staff by cutting the stems of the Japanese Barberry while participating on Volunteer Work Days.

  • Park biologists may follow up with an application of an appropriate herbicide.

• Multiflora Rose: Visitors can assist park staff by cutting the stems of the Japanese Barberry while participating on Volunteer Work Days.

  • Park biologists may follow up with an application of an appropriate herbicide.

• Wineberry: Visitors can assist park staff by cutting the stems of the Japanese Barberry while participating on Volunteer Work Days.

  • Park biologists may follow up with an application of an appropriate herbicide.

Herbs

• Garlic Mustard: Visitors can assist park staff by cutting the stems of the Japanese Barberry while participating on Volunteer Work Days.

  • Park biologists monitor known sights throughout the growing season.

• Japanese Stiltgrass: Visitors can assist park staff by cutting the stems of the Japanese Barberry while participating on Volunteer Work Days.

  • Park biologists are studying pre-emergent herbicides to manage the plant before it starts to grow.

• Wavyleaf Basketgrass: Volunteers assist park staff by reporting sightings of the species and pulling the shallow-rooted plants by hand while participating on Volunteer Work Days.

  • Park biologists apply herbicides to the more established, larger infestations.

Trees

• Callery Pear: The most effective help is to report sightings of the trees, as pulling or cutting of the plant causes more aggressive growth.

  • Herbicides are applied to the trunks of the Callery Pear by park biologists.

• Tree of Heaven: The most effective help is to report sightings of the trees, as pulling or cutting of the plant causes more aggressive growth.

  • Herbicides are applied to the trunks of the Tree of Heaven by park biologists.

Vines

• Chinese Yam: Volunteers assist park staff by reporting sightings of the species and pulling out the plants by hand while participating on Volunteer Work Days.

  • Park biologists follow up with cutting vines and spraying herbicides.

• Japanese Honeysuckle: Volunteers assist park staff by reporting sightings of the species and cutting the vines by hand while participating on Volunteer Work Days.

  • Park biologists follow up with cutting vines rom trees, mowing affected fields and spraying herbicides.

 

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Reporting with iNaturalist