Mowing your lawn less often is better for the grass, flowers and bees.
June 8, 2018

New study says skip the yard work this weekend; cutting grass less frequently leads to a healthier backyard ecosystem

"Gonna be a hot one today," you think as you look out the kitchen window on a Saturday morning. The last thing you want to do is mow the lawn.

What say you spend the day in the air conditioning with a glass of iced tea instead? Sound good? Of course it does.

But what if not cutting the grass made you an environmental hero by nursing the health of your immediate ecosystem? Sounds even better.

Trimming the verge every two weeks instead of weekly could help bees and the plants they gather pollen from, according to a recent study which an Arizona State University faculty member contributed to. The study was published in the journal Biological Conservation.

The “lazy lawn mower” approach favors a look which is a little bit more meadow and less center court Wimbledon, said Christofer Bang, a lecturer in the School of Life Sciences. It’s more than a lawn out there. It’s a little ecosystem.

“Many people tend to perceive a fresh cut lawn as an indication of a well maintained garden, and this perception is something we try to adjust by highlighting the many organisms in the small ecosystem (that) a garden really is,” Bang said. “It’s so much more than a lawn, even when there’s not really many rose bushes or begonias."

The advantage to caring for your local bees? They pollinate 87 percent of all flowering plants. Bee-dependent trees, shrubs, garden plants, and spontaneous flowers present in cities and suburbs provide shade, reduce air pollution, increase property value, and enhance wildlife habitat.

Video by Jamie Ell/ASU Now

Researchers mowed 16 lawns in western Massachusetts suburbs at frequencies of one, two and three weeks.

Lawns mowed every three weeks had two and a half times more lawn flowers than the other frequencies. Interestingly, lawns mowed every two weeks supported the highest number of bees yet the lowest bee richness and evennessthe amount of variety of bees. Researchers suspect higher grass at the three-week point prevented bees from reaching the clover and dandelions beneath.

“If you think about mowing your lawn as a form of disturbance of the little ecosystem, you also find that things may change if you alter the frequency of this disturbance,” Bang said.

More abundant flowers, easier access to flowers, and a more drastic impact on grass biomass and floral resources (compared with three-week yards), two-week yards were the sweet spot.

“Mowing less frequently is practical, economical and a time-saving alternative to replacing lawns or even planting pollinator gardens,” said Susannah Lerman, who authored the study and works as an ecologist at the University of Massachusetts Amherst and the U.S. Forest Service.

Changing how often you mow is a new and creative approach for supporting urban biodiversity by rethinking what role lawns play in enriching urban areas.

“Mowing less frequently … has the potential to be widely adopted if it can overcome barriers to social acceptance,” the researchers wrote. “Most importantly, our research shows that individual households can contribute to urban conservation.”

Above photo: NAU sophomore Bryson Leander mows his family's backyard lawn in north-central Phoenix on Thursday, May 31. While home on summer break, he cuts the grass every 10 days to two weeks, depending on irrigation and rain. An ASU researcher, Christofer Bang, and his colleagues produced a study experimentally testing whether different lawn mowing frequencies influenced bee abundance and diversity. Photo by Charlie Leight/ASU Now. Special thanks to Bryson Leander.

Scott Seckel

Reporter , ASU Now

480-727-4502