News Release

Saguaro National Park Resumes Herbicide Use to Control Invasive Buffelgrass

NPS employees standing near saguaro cactus

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News Release Date: July 7, 2021

Contact: Perry Grissom, 520-405-4549

Tucson, AZ – Saguaro National Park will join other state, county, and city lands agencies to initiate seasonal herbicide use to control invasive plant species within the boundaries of the park starting July 13, 2021. Ground crews will utilize backpack sprayers to target invasive buffelgrass in areas where the grass has started to green up after the rain.

Work will continue throughout the monsoon season in both districts, weather and moisture permitting. Most treatment areas are away from roadways or trails and no closures are anticipated. Sprayed areas will be identifiable by a blue dye and will be signed if the work is visible from trails. A treated area is safe to pass through once the chemical has dried in approximately 15 minutes after spraying.

Buffelgrass is the primary target of the park’s invasive species control program and is an aggressive, non-native grass that competes with native plants such as saguaros, paloverdes, and many other native Sonoran Desert plants. Buffelgrass can also carry hot and intense fires in an ecosystem that is not adapted to fire. Buffelgrass is a serious threat to biological conservation efforts and buffelgrass fires are a major threat to public safety and property. Buffelgrass is listed as a noxious weed by the state of Arizona. Other invasive non-native plants such as fountain grass, natal grass, and African lovegrass will also be treated if found.

Large caches of water have been placed within the park’s wilderness for the safety of the working crews. Please do not disturb these caches if found.

The Park has been using ground-based herbicide applications with back-pack sprayers to control buffelgrass and other invasive non-native species since 2005. During the dry months, when the grasses are not green, park employees and volunteers, including local residents and school groups have been instrumental in helping to manually remove buffelgrass in the park. Tucson Clean and Beautiful, Sonoran Desert Weed Wackers, and many other groups are all working to control buffelgrass in the Tucson community. Manually digging and pulling buffelgrass is a slow, labor-intensive process, and pulling alone cannot keep up with rapidly spreading buffelgrass.

For additional information, please visit these websites:
Save Our Saguaros - Beat Back Buffelgrass (

Last updated: July 9, 2021

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