March 13 (UPI) -- American lawns can offer surprisingly good habitat for bees, but not if they're mowed too often. New research suggests the sweet spot is one mow every two weeks.
Researchers with the U.S. Forest Service studied bee activity in 16 residential lawns over a few summer months. Each of the lawns was cut either once a week, once every two weeks or once every three weeks. All of the suburban yards were pesticide free.
Throughout the study, scientists monitored bee abundance and diversity among the grassy acreage. Their observations showed lawns mowed every two or three weeks hosted greater bee activity than those mowed once a week.
Lawns mowed every two weeks featured the greatest abundance of bees, while lawns mowed every three weeks boasted a larger number of pollinated flowers and a greater diversity of bee species.
Among the 16 studied lawns, scientists identified 111 different species of bees.
"We found that backyards can be a surprisingly beneficial habitat for bees," lead study author Susannah Lerman, a research ecologist with the USDA Forest Service's Northern Research Station, said in a news release. "Mowing less frequently can improve pollinator habitat and can be a practical, economical, and timesaving alternative to lawn replacement or even planting pollinator gardens."
With 40 million acres of lawn in the United States -- from parks to yards, football fields to golf courses -- changes in lawn care management could have a significant impact on the population health of native bee species.
"Lawns managed to promote bees have the potential to improve bee abundance," Lerman said.
Researchers published their study of suburban bees in the journal Biological Conservation.