In 2019, a group of British conservationists came up with an idea so simple in its execution, so clever in its marketing, and so seemingly beneficial in its outcomes that it swept across the globe.
The nonprofit Plantlife started a community-science project asking participants to leave their lawns uncut in the month of May and count the number of flowers that appeared. They called it “No Mow May” in the hope that it might lead to a proliferation of food sources for pollinators.
It wasn’t long before the practice with the catchy title began to take root in the United States, first in Wisconsin and then across the country. In the Hudson Valley, communities like New Paltz have adopted resolutions in support of No Mow May. Others, like Ossining, have encouraged the practice, with caveats. After all, what could be easier than asking people to stash their lawnmowers in the garage for an extra month so that lawns might welcome more crocuses than croquet?
“I believe that people have great intentions and want to help,” says Joellen Lampman, a specialist with Cornell Cooperative Extension’s Turf Team. “Initiatives like No Mow May can be very tempting and allow us to check ‘helping pollinators’ off our to-do list.”
If only it were that easy. In the years since the movement began, a growing body of research has begun to show that a simple idea doesn’t always produce intended outcomes across diverse and complex ecological systems. In Wisconsin, an often-cited study that suggested an increase in bee abundance and diversity was later retracted over “inconsistencies in data handling and reporting.” That led the Wisconsin city of Appleton, which reportedly was the first in the nation to officially adopt No Mow May, to remove it from its city code.
“We are not seeing any benefits to pollinators for holding off on mowing until the end of May,” Lampman says. “Even in England, where the initiative behind No Mow May started, they found no significant increase in nectar by the end of June.”
Some newer studies suggest mowing can have benefits, provided it is done at certain intervals. A study of 16 suburban yards in western Massachusetts found that lawns mowed every three weeks had as much as 2.5 times more lawn flowers than the other frequencies, yet those mowed every two weeks “supported the highest bee abundance.” In other words, while more flowers were present in the three-week plots, they were hidden by tall grass.
“Our results,” the authors wrote, “highlight a ‘lazy lawnmower’ approach to providing bee habitat. Mowing less frequently is practical, economical, and a timesaving alternative to lawn replacement or even planting pollinator gardens. Given the pervasiveness of lawns coupled with habitat loss, our findings provide immediate solutions for individual households to contribute to urban conservation.”
For those who do want to go the extra mile, starting with a small pollinator garden and slowly expanding it over the years to convert more lawn to habitat can be worthwhile. While there are many great resources out there on how to create these gardens, gardeners should be prepared for several years of more intensive care and weeding before a pollinator garden becomes a thriving, low-maintenance habitat feature.
Ongoing Cornell Cooperative studies are showing that mowing at certain intervals can promote turf quality. “The important part there,” says turf team specialist Carl Schimenti, “is that by minimizing total growth, you are minimizing the nutrient mining the plants are doing. Less nutrients removed equals less nutrients that need to be applied [via fertilizer].”
Turf experts say that the optimal mowing frequency is one that cuts no more than the top third of a blade grass, and that setting mower blades at least 3.5 inches above the ground will leave a significant number of small flowers, such as dandelions, present in the lawn.
One of the frequent arguments against No Mow May has been that tall grass invites ticks and the spread of Lyme disease. But the science does not support this, either. “I’m aware of no evidence that shorter lawns or more frequent mowing reduces tick abundance, although the caveat is that this hasn’t been studied very often,” says Dr. Richard Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies in Millbrook. “The vast repetition of inaccurate claims that blacklegged ticks are most abundant in tall grass is unfortunate and misleading.”
If No Mow May and other civic-driven initiatives like it have one big benefit, it may be that they raise awareness and inspire people to consider the impacts of land-management practices. “The earth is very complex in how it works,” says Connor Stedman, an ecological designer who works in the Hudson Valley and was the lead faculty for the Omega Center for Sustainable Living’s Ecological Literacy Immersion Program. “And it’s also very localized in how it works. There is a lot of local variation and site variation.”
Stedman says that growing civic and community education around ecology is a critical first step in coping with habitat loss for not only pollinators, but also for insects and invertebrates, a foundational part of the natural world’s food web. “What is happening around us in the ecosystem is very interesting and it is detailed and does require looking closely at the small details around you,” he says. “Any chance to convey that — to slow down, to take a closer look and learn about what you see — is helpful for encouraging people in the right direction.”
Call it “Know More May.”
