USA NPN National Phenology Network

Taking the Pulse of Our Planet

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Invasive buffelgrass chokes out native plants and presents a fire risk to native desert communities. 

Image credit:
Camille McCollum

Buffelgrass Forecast

Buffelgrass is an invasive plant that impacts native desert plant and animal communities in the Southwestern US. It creates substantial fire risk in ecosystems that are not adapted to large-scale intense burning. 

Buffelgrass current day forecast

Buffelgrass Current Day Forecast.

Buffelgrass 1-2 week forecast

Buffelgrass 1-2 Week Forecast.

Pheno Forecast maps predict key life cycle stages in invasive and pest species, to improve management efficacy. The buffelgrass Pheno Forecast (Gerst et al 2021) is based on known precipitation thresholds for triggering green-up to a level where management actions are most effective. These maps are updated daily and predict green-up one to two weeks in the future.

Help us improve these maps! Our Pheno Forecast map products are still in development, and we seek input on their performance in your area. Visit our buffelgrass green-up reporting page and let us know if you see greenness on your plants. Reports of buffelgrass greenness appear at the bottom of this page. We also welcome your feedback on the maps; you can share thoughts on the right sidebar of this page. 

New in 2021: Compare station-based forecasts of buffelgrass greenup to these gridded forecasts in the Visualization Tool.

Species Background

Buffelgrass (Pennisetum ciliare) is originally from Africa, Asia, and the Middle East and was brought to the United States for erosion control and grazing. In recent years, it has been expanding throughout the Southwestern US where it can threaten native species and transform desert ecosytems by promoting fire where plants and animals are not adapted to large, intense burns. Treatment by manual removal or herbicide spraying can help restore native communities. 

Greenness Forecast

buffelgrass Photo: Arizona-Sonora Desert Museum

We forecast buffelgrass greenness based on precipitation totals for the previous 24 days. Approximately 50% greenness is reached when at least one inch of rain falls in a 24 day period (Wallace et al. 2016). Note that these maps predict the onset of this stage, and do not represent continued greenness duration. The ideal time to target plants for treatment is after a substantive period with no rainfall. Treatments are ideally applied when approximately half of the plant has greened up, and prior to reproduction. For specific information on preferred treatment options in your region, we recommend contacting your local extension agent.  Additional treatment resources are available at Tucson Clean and Beautiful and the Arizona-Sonora Desert Museum.

Greenness status

Accumulated Precipitation over 24-day rolling timeframe (inches)

Relevant Location


Greenness unlikely

 < 1 inch



 50% greenness may occur in 1-2 weeks

 1-1.7 inches

Tucson Mtns, Tucson, AZ

Wallace et al. (Remote Sensing)

 50% greenness will likely occur in 1-2 weeks

 > 1.7 inches

Catalina Mtns, Tucson, AZ

Wallace et al. (Remote Sensing)

This product has been created in part with a grant from the Technology and Research Initiative Fund through the Arizona Institutes of Resilience.

More information on map development and re-use policy. Raster layers for buffelgrass maps can be downloaded by using the USA-NPN Geoserver Request Builder

Explore the forecast in our Visualization Tool.

Explore Forecast

Observations of buffelgrass greenness contributed in 2023

This map displays locations where observers reported buffelgrass via the reporting form in 2023. Green dots indicate locations where an observer reported buffelgrass plants with 50% or more green leaves. The size of the dots indicates the percent of green leaves on the plant. Brown dots represent buffelgrass plants that were less than 50% green. Gray dots indicate dormant buffelgrass.