Meadow Management at Valley Forge

The Grand Parade meadow near Muhlenberg's Brigade in early autumn.

NPS Photo

Habitat, Clean Water & Rich Soils

Meadows and grasslands are vital to the natural and cultural heritage of Valley Forge and southeastern Pennsylvania. They provide important habitat for many bird species and for pollinators like moths, butterflies, and bees. They improve water quality and enrich the soils.

Meadows also need consistent intervention to remain meadows, whether by natural procesess or by human ones. They need regular grazing, fire, mowing, or other interventions either natural or managed by humans, in order to remain meadows — without one or more of these forces at play, they will convert to forests over time.

 

Fighting Invasive Plants

Invasive plants are destroying habitat for native species in the meadows at Valley Forge. Restoring these meadow landscapes helps to preserve native biodiversity and also protects scenic open spaces providing recreational, educational, and cultural opportunities for local residents and park visitors alike.

 

 

Select meadows in Valley Forge National Historical Park will undergo herbicide treatments conducted by contracted and permitted companies.

NPS Image

Herbicide Treatments in Select Meadows (Summer 2025)

Valley Forge National Historical Park uses several methods to manage meadows as high-quality habitat for native wildlife—including mowing, haying, native plant seeding, and manual and chemical removal of non-native invasive plants.

During the summer of 2025, contracted and permitted companies will be treating selected meadows with an herbicide (see map for locations). The herbicides do not affect grasses, and target woody species like the invasive autumn-olive, oriental bittersweet, Japanese honeysuckle, and Himalayan blackberry. The treatments will provide the space needed for native grasses and flowers to grow, which in turn will better support native insects and birds.

Flagging and signage are posted in the meadows that are being treated to warn visitors. Do not enter meadows when flagging is posted.

Park staff will continue to monitor the meadows throughout the year to evaluate the success of treatments and native plant and wildlife response.

 

Frequently Asked Questions

Why did you pick the fields that are being treated?

The meadows managed by Valley Forge National Historical Park have been ranked in terms of current and potential habitat value. We prioritize treatments in these high priority meadows. Factors that influence how meadows are ranked include size, historical biodiversity, current biodiversity, potential biodiversity, and cultural and interpretive values.

Why not use fire or some other tool?

While fire is a great tool for meadow management in some places, park staff have determined that the dense suburban environment surrounding Valley Forge, especially with residential areas and a children’s hospital less than 2 miles form the park, fire is not an appropriate tool at Valley Forge National Historical Park.

Why is such a large area being treated all at once?

Treating large areas at one time is more efficient for cost and labor for heavily infested areas. Treating large areas also means a lower chance of invasive plant seed from outside of the treated area making its way back into the treated area.

How will this impact the animals / plants? Won’t they disappear?

The herbicides used have low or no acute toxicity for animals. These treatments will remove non-native plants, and those will be replaced by native plants. Native pollinators, such as butterflies, need native plants for their larval food sources. Removing non-native plants leads to more native plants and native insects, which in turn feeds mor native birds. In the short term, some cover and food may be lost, but in the long term, as non-native plants are replaced by native plants, there will be more food for native animals, and cover will return.

Is the herbicide toxic to me, my pet, wildlife?

The herbicides used have low or no acute toxicity for animals. Short-term effects on wildlife are minimal and are outweighed by long-term habitat improvements. Applicators will use a blue colorant and flags to indicate areas treated. The herbicides are not toxic if visitors and their pets stay out of treated areas while the flags are still up.

What about monarchs?

Native milkweeds are the plants required by monarch larvae. At any one time, there are several fields not being treated that have milkweed plants. Additionally, large milkweed patches in treated fields are avoided when applying herbicides. Our seed mixes that are planted after treatments include native milkweed. In the long run, treatments will result in more milkweed available for monarch larvae and more nectar plants available for adult monarchs.