Weed Warriors

Volunteers spread mulch in a forest.
Volunteers help lay down Mulch at National Public Lands day.

NPS Photo.


The War on Weeds

As suburban sprawl covers the land around Valley Forge National Historical Park, the park becomes increasingly important as a refuge for native plants and animals. The habitats in the park, including oak/poplar forests, meadows, wetlands, water, and forested floodplains, support over 1,000 different kinds of plants and 300 animal species.

Approximately 1/3 of the plants in the park are non-native. Thirty of these non-native plants also are considered invasive or 'weedy' species that will or are likely to cause significant environmental or economic harm and/or pose a threat to human health. Non-native, invasive plants are our target in the 'war on weeds.'
Two volunteers help plant a tree.
Two volunteers help plant a tree at National Public Lands Day.

NPS Photo.

Why We Fight

The spread of non-native, invasive species is one of the leading causes of ecosystem degradation and loss of biodiversity world wide. These plants tolerate a wide range of environmental conditions, such as temperature, shade, and moisture. They possess traits that allow them to spread rapidly, such as prolific seed production and rapid growth rate. Additionally, the predators, parasites, and diseases that keep these species in check in their native lands are not present here.

The negative impacts that non-native invasive plants have on native plants and animals is called biological pollution or biopollution. At Valley Forge invasive plants are considered a direct threat to natural resources because they:
  • Out-compete native plant species for light, space, nutrients, and water.
  • Interfere with natural ecosystem processes such as forest regeneration, erosion and deposition, and nutrient cycling.
  • Threaten native wildlife by reducing the availability and quality of food resources.
It is estimated that non-native plants spread into an area the size of Delaware each year. At Valley Forge, all habitats are experiencing some level of degradation and loss of diversity due to the spread of these aggressive invaders.

But, What Can I Do?

Volunteer as a park Weed Warrior and participate year-round in activities to remove different types of non-native, invasive plants. 'Weed' removal is accomplished using mechanical methods such as hand pulling and cut and cover, and may involve the use of hand tools. This is great for both groups and individuals. Participants should come prepared to get down and dirty!

All ages are welcome and park staff will provide necessary training and equipment, including gloves and eye protection. Participants should wear long pants, a long sleeve shirt and closed toed shoes such as hiking boots.

Receive a Weed Warriors button the first time you participate, and earn a Weed Warriors t-shirt after you participate three times!
Two volunteers help install fencing.
Two young volunteers help install fencing.

NPS Photo.

How to Join

Upcoming Dates in 2020:

Saturday Jan 11, noon to 3PM
Saturday Mar 21, noon to 3PM
Saturday Mar 28, noon to 3PM
Saturday April 11, noon to 3PM
Saturday May 9, noon to 3PM
Saturday June 6, time TBA, part of National Trails Day

Some dates fill up quickly, so sign up early! - The best way to reserve your space is to email the Natural Resources staff directly at the email below.

To join the Weed Warriors visit volunteer.gov, or email our Natural Resources staff.

Last updated: March 9, 2020

Contact the Park

Mailing Address:

1400 North Outer Line Drive
King of Prussia, PA 19406


(610) 783-1000

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