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Spicing up native plant restoration

Posted date: August 29, 2018

Coating native plant seeds with spicy pepper oils provides effective, economical protection

Have you ever touched a hot pepper and then rubbed your eyes? Chances are you will not want to go near the pepper again. A new study found that you can use this same concept to deter rodents from eating seeds, thus protecting investments in native plant restoration efforts.

A recent study, “Spicing up restoration: Can chili peppers improve restoration seeding by reducing seed predation?” by RMRS research ecologist Dean Pearson and others, applied this concept to native plant seeds during a 4-year study conducted in the Intermountain grasslands of western Montana.

Spicy and nonspicy seeds used for restoration projects and helping deter seed predation
Spicy and non-spicy seeds
“I work with lots of resource managers and see them trying to seed restoration areas,” says Pearson. “I see seeds getting eaten and wondered, can we protect these seeds with hot peppers?”

Rodent granivores, like deer mice, eat seeds as their main food source, which can inhibit restoration efforts in a variety of plant communities. The researchers used the active ingredient that creates heat in peppers, capsaicin, and coated native plant seeds with the same active ingredient, hoping to deter rodent granivores. The researchers in this study used finely ground powder from Bhut Jolokia or ghost pepper, a pepper with extremely high capsaicin concentrations. The powder is readily available and inexpensive, making it better suited for the study rather than pure extracted capsaicin.

The 4-year project included both laboratory and field experiments with the seeds – placing the seeds in controlled conditions, as well as in sites of prolonged exposure to the outside elements. They found that applying a capsaicin coating to spring-germinating seeds sown in late winter increased native plant recruitment. It also reduced the total cost per established seedling. The work done on this study demonstrates the possibilities hot peppers can play in successful restoration practices. 

“Using nature’s tricks, thinking about them and considering them for restoration projects, is a pretty neat concept,” says Pearson. 

Related Publications

Pearson, Dean E. ; Valliant, Morgan ; Carlson, Chris ; Thelen, Giles C. ; Ortega, Yvette K. ; Orrock, John L. ; Madsen, Matthew D. , 2018

The Rocky Mountain Research Station (RMRS) is one of seven units within the U.S. Forest Service Research and Development. RMRS maintains 14 field laboratories throughout a 12-state territory encompassing parts of the Great Basin, Southwest, Rocky Mountains, and the Great Plains. RMRS also administers and conducts research on 14 experimental forests, ranges and watersheds and maintains long-term research databases for these areas. While anchored in the geography of the West our research is global in scale. To find out more about the RMRS go to You can also follow us on Twitter at




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Jennifer Hayes
Public Affairs Specialist