Princeton University
OP-9: Landscape Management

Eight organically managed Green Rooves are not included in the area of managed grounds because of a lack of data. 

The Stony Ford Center and various meadows on campus are managed without inorganic fertilizers or chemical pesticides, fungicides, or herbicides. 

The main campus is managed in-house with tree inspection help from Wells Tree Service and Aspen Tree Experts. The IPM objective is to use cultural practices, good plant selection, and soil remediation to have healthier plant material and, therefore, plants that can tolerate pests. Aspects of the plan include using the least toxic chemical pesticides; minimum use of chemicals; use of chemicals only in targeted locations and only for targeted species; and biological control through the release of beneficial insects (e.g., ladybugs) and larvae (e.g., green lacewing larvae).

All University plantings are selected for appropriateness in Princeton, New Jersey's hardiness zone, as defined by the U.S. Department of Agriculture. Additionally, the University chooses plantings by considering soil and watering requirements and their proven ability to flourish in this campus environment. When possible, Princeton protects and uses existing vegetation on campus and in its natural areas. When feasible, the University uses natural methods to control weeds, insects, and fungi. An example of this is the University's integrated pest management program: periodically, the University releases a variety of beneficial insects and larvae.

The 2026 Campus Plan established the University’s approach to stormwater management by focusing on restoring natural resources, incorporating an ecological systems approach, and promoting the implementation of green infrastructure (GI) for all new developments on campus. Through the 2016 and 2026 Campus Plans, the University has built an extensive network of green infrastructure best management practices (GI BMPs) to reduce rainwater runoff and improve water quality. These GI BMPs include green roofs, stream restoration, bioretention systems, porous pavement on paths and parking, infiltrating turf fields, subsurface storage, rainwater harvesting systems, and manufactured treatment devices. Today, there are over 150 GI BMP installations on campus. Before the 2026 Campus Plan, the University conducted campus-wide monitoring and metering to measure water quality and discharge flow at Lake Carnegie. Currently, the University is reactivating this program to measure water quality and quantity improvements resulting from the 2026 Campus Plan projects, creating a comparative baseline to track progress. The University also integrated stormwater management as a primary goal in the 2019 Sustainability Action Plan by establishing a comprehensive system to track the area on campus that meets the Campus Plan stormwater goals over time. Areas of land that align with New Jersey Department of Environmental Protection regulations and the Campus Plan stormwater goals are considered areas under enhanced stormwater management. As of 2023, 191 acres (including 65 acres of paved impervious area) were under enhanced stormwater management on the main campus and Meadows Neighborhood combined. Updates to the stormwater strategy outlined in the 2026 Campus Plan are underway, and a comprehensive stormwater study is anticipated to be finalized in August 2024. These updates will ensure that the University is going beyond mere regulatory compliance and guide the University's continued commitment to enhancing existing natural resources and bolstering resilience on campus. 

Nearly 100 percent of the leaves and landscape trimmings collected on campus are composted and re-used as a soil amendment on campus grounds. Since 2018, the University has also generated and utilized compost from its on-site in-vessel composting system. As part of the Sustainable Composting Research at Princeton (S.C.R.A.P.) In the lab project, the aerobic digester converts food scraps and compostable products into compost while serving as a living laboratory for multi-disciplinary investigations into all aspects of organic recycling.

Several campus buildings include green roofs which support wildlife habitat, minimize stormwater run-off, and reduce building heating and cooling costs through lower maximum and higher minimum roof membrane temperatures.

Whenever possible, Grounds staff uses natural fertilizers on the University's campus, such as compost tea and mulch. Incorporating natural materials as amendments into the soil also reduces synthetic chemical use. However, weather conditions and campus activities sometimes require the use of synthetic fertilizers. The University completes pre-storm treatment on campus to better prepare the campus before snow. Additionally, the University uses environmentally safer chemicals, such as calcium magnesium acetate, to remove snow.

Princeton University’s food waste demonstration project: https://scraplab.princeton.edu/