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South Side Park – Jurassic Valley Habitat Restoration & Herbicide Application Completed Fall 2025

Project Objectives

  • Support maintenance of current restoration efforts in ‘Jurassic Valley’
  • Regain access and restore native plant communities to 2 new acres in ‘Jurassic Valley’
    • Add at least 1 acre of urban canopy coverage and enhance existing forest structure
  • Reduce damage to City of Pittsburgh infrastructure
  • Improve habitat and integrated pest management (IPM) opportunities around Bandi Schaum Community Garden
  • Promote a healthy and resilient forest with a strong component of native Pennsylvania species
  • Contribute to Phase 1 objectives of the South Side Park Master Plan; may reduce costs of Phase 1 implementation

FAQs

Where is this project happening?

In the ‘Jurassic Valley’ portion of South Side Park. The area is near the Sterling St. steps and the Greely St. parking lot. See the map below.

Who is involved with this work?

Audubon Society of Western Pennsylvania

Formed in 1916, ASWP seeks to connect the people of southwestern Pennsylvania to birds and nature through their programs, projects, and places. ASWP owns and operates three nature centers and four other conservation properties around Allegheny and Butler counties. ASWP regularly manages habitat on their properties through a combination of manual, mechanical, and chemical techniques and always follows best practice guidance from subject experts.

Tim will be the herbicide applicator. Tim has controlled knotweed and other invasive plant species on all other ASWP properties, including those of similar sizes.

Friends of South Side Park

FOSSP was created in 2015 in partnership with the City of Pittsburgh and local nonprofits to help fill the community engagement, stewardship, and advocacy needs of South Side Park. FOSSP has lead restoration in the park and planted over 1,800 trees to date.

Is herbicide necessary or the only option?

Unmanaged knotweed stands reduce biodiversity, can increase erosion, and can damage local infrastructure. Knotweed is known to produce a chemical in its roots that prevents growth of other plants allowing for quick and successive spread. Knotweed is an incredibly resilient plant and can sprout new plants from root fragments. Mowing, cutting, and digging can be effective in preventing a stand from growing larger, but a chemical herbicide application is the most effective technique to provide long-term control of knotweed.

What herbicide is being applied?

A glyphosate product labeled for use near or in aquatic environments will be mixed with an oil-based carrier. This mix is widely used in restoration work across North America and is effective for knotweed control. The mix is applied to the leaves of knotweed with a backpack sprayer by a certified applicator. Once absorbed by the plants, the chemical disrupts chemical pathways in the root of the plant resulting in complete death of the plant.

Is the application harmful to humans, animals, plant life, or our waterways?

When applied properly, this application does not pose a threat to humans, wildlife, or our waterways. The chemical does not persist in the soil, nor can be absorbed by a plant through soil. Once in the soil, the chemical binds with clay and will not run off or leach in groundwater. Glyphosate quickly degrades to non-toxic levels and into component chemicals once applied. The chemical is non-volatile and does not vaporize from surfaces or in the air. The application will be precise and targeted, with the applicator only applying to plants within a few feet.

When is the application?

There will be two applications, the first will occur in late summer 2025, 6-8 weeks after cutting and eating by a herd from Allegheny Goatscape. The cutting and waiting period allows knotweed to regrow to a shorter height for easier and more complete treatment. The timing of the treatment coincides with a higher flow of nutrients towards the root system, providing more complete control.

A second application will occur in late summer 2026 to follow up and catch missed or resprouting knotweed.

Will the knotweed grow back?

Some knotweed is expected to regrow following the first treatment, the second treatment is designed to capture these resprouts and will provide complete control. These applications will not control knotweed adjacent to the targeted areas, so knotweed may reinvade the area, but these small intrusions may be controlled manually.

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