The study, published this week in Restoration Ecology, tested whether removing thatch—dead leaves and debris—could allow native seeds to germinate and grow. Compared to other techniques for managing invasive grasses, such as controlled burns, hand weeding, and spraying herbicides, raking is decidedly less labor-intensive and more ecologically friendly.

"In these ecosystems, native seeds often fall on thick layers of thatch and can't germinate. Raking the thatch lets light in and gives native plants a chance to grow," said Marko Spasojevic, study author and UCR associate professor of plant ecology.

In grasslands near the UCR campus, researchers used a grid of paired plots—one raked and one untouched—to measure plant community changes over the course of three years. Results showed that raking increased plant diversity overall, reducing invasive grasses like ripgut brome while increasing both native and exotic wildflowers, known as forbs.

Ripgut brome, a dominant invasive grass, earned its name from its sharp, bristly hairs, which can injure grazing animals.

"It's super nasty for sheep and cattle to eat," Spasojevic said. Meanwhile, native flowers like the common fiddleneck, prevalent in Riverside, benefited modestly from raking.