Cities across Michigan are rethinking “No Mow May” policies amid fears that taller grass could attract ticks and growing evidence that skipping mowing for just one month does little to help pollinators.

The annual initiative encourages residents in Michigan and around the world to hold off on mowing in May in order to create more space for bees, butterflies and other pollinators at a time when food is scarce. Some ornamental flowers, like bee balm and sunflower, don’t bloom until mid-June, leaving early-season pollinators with fewer sources of nectar and pollen.

Still, experts say the impact of a one-month pause may be overstated. Research is limited on whether letting grass grow for only a few weeks meaningfully helps pollinators, according to David Lowenstein, a consumer horticulture expert for Michigan State University.

“The science is not there to show it’s going to have a meaningful impact on bees,” Lowenstein told Bridge Michigan. “Bees need two things: food to eat, which comes in the form of pollen and nectar, and a place to nest, which could either be underground for cavity-nesting bees or in logs.”

The concept behind No Mow May took off in 2019, when the British conservation group Plantlife began promoting it as a simple way to support pollinators. Letting clovers, dandelions and other low-growing plants flourish can provide nectar and pollen, while also reducing water use.

But rather than abandoning mowing altogether, Lowenstein suggests a more balanced approach.

“What would be a better rebranding would be something like, ‘Reduced Mow May” … because there are certain kinds of low-growing flowers in lawns like violets and white clover that are good for bees,” Lowenstein said.

“Many bumble bees and smaller bees do visit those and if you were to let your lawn grow a little bit higher, maybe mowing it … every two or three weeks, if you could, would allow for some of those weeds that are good for bees to grow.”

That shift toward longer-term solutions is reflected in East Lansing, where officials recently adopted a resolution redefining what counts as weeds and allowing for year-round pollinator-friendly landscapes.

“No Mow May raised real awareness about pollinators and got a lot of residents thinking differently about their yards,” Cliff Walls, the city’s environmental sustainability and resiliency manager, said in a statement.

“But a one-month mowing enforcement pause was never going to be the long-term answer.”

Under East Lansing’s new rules, plants taller than 6 inches can qualify as a native garden or lawn if they are intentionally planted, clearly defined, made up of native species and properly maintained.

The ordinance “gives us a durable, year-round framework that supports ecological landscaping while keeping clear, fair expectations for property maintenance,” Walls said.

Tick fears

Other Michigan cities are also rethinking how to support pollinators, with several moving away from the one-month model.

Ann Arbor’s city council approved a No Mow May ordinance in 2022, but later replaced it with a broader Pollinator-Aware Yard Care initiative after hearing mixed feedback from residents.

“When we had that ordinance in effect for 2022, we received a lot of public comment from folks, a lot of folks in support of the program and a lot of folks with concerns about the program,” said Sean Reynolds, senior analyst for the city’s Office of Sustainability and Innovations.

Among those concerns were unintended side effects, including the potential for taller grass to attract ticks.

“Back in 2022, when we had the No Mow May ordinance, there were concerns around infective species, especially ticks, which was a concern that we heard and part of the reason we wanted to transition to something that’s a little more flexible,” Reynolds said.

When the grass grows too high, it creates a more inviting environment for ticks, especially during this time of year when they are most active.

The concern is not theoretical.

According to the Michigan Department of Health and Human Services’ 2026 Lyme Disease Risk Map, 82 of the state’s 83 counties have a known or potential risk for Lyme disease, driven in part by the spread of blacklegged ticks.

Instead of pausing mowing altogether, Ann Arbor now encourages residents to plant native species, shrink traditional turf lawns, limit pesticide use and reduce light pollution.

A “critical time” for pollinators

A similar mix of approaches is playing out elsewhere.

In Jackson, officials launched a limited version of No Mow May in 2023, allowing residents to let backyard grass grow while still requiring front yards and street-facing areas to be maintained. The program was reinstated this year after a brief pause.

“There are usually a lot more prevalent flowers after May, so that’s why May is such a critical time for pollinators because there are fewer options for them,” said Christina Crouch, communications manager for the city. The initiative is making “a small impact over time,” adding more resources and options for pollinators, Crouch said.

Even so, participation comes with clear boundaries: only backyards qualify, while front yards, including strips along the road, must still be mowed.

Meanwhile, Ferndale has taken a different route. After launching its program in 2023, the city ended No Mow May in 2025, citing limited evidence of its effectiveness despite strong initial participation.

More than 700 Ferndale households participated in an initial pilot program, but the city subsequently evaluated whether No Mow May programs are effective.

The conclusion: “They are not.”

“This is mostly due to the lack of pollinator-friendly vegetation present in the typical suburban/urban turfgrass lawn, meaning that the plants that do grow when not being mowed do not contribute to pollinator habitats in any meaningful way,” the city explained on its website.

Ferndale now recommends residents maintain cut grass that is three or four inches tall to outcompete weeds, reduce air and noise pollution by mowing less often and only remove about a third of the grass each time.

___

This story was originally published by Bridge Michigan and distributed through a partnership with The Associated Press.