Inside: Read about the drawbacks to No Mow May for honey bees, native bees, and homeowners, too.
Lyrical but not logical
I’m jubilant to reach the end of a month laden with tall-grass prairies in suburban front yards. But why? Why would a bee-loving environmentalist like me think No Mow May is a bad idea?
Some people stop mowing for the sake of honey bees and others for the sake of other pollinators, including solitary bees. But No Mow May is a silly idea. The name is catchy, both alliterative and rhyming, but the allure ends there. As far as I can tell, it has little benefit for pollinators.
Six strikes against No Mow May
No Mow May sounds reasonable at first: By letting spring weeds flower without cutting them, we can provide hungry pollinators extra forage early in the year. Sounds good, right?
But does it truly boost pollinator health and survival? What happens to those happy critters on June 1? Do they become mulch with the first pass of your lawn mower? Or do they pack up and leave for a safer environment?
Let’s look at some downsides of No Mow May, beginning with honey bees.
In North America, which month has the most natural forage? We know it occurs in spring, probably in April, May, or June. My guess is May, a month when everything blooms: trees, shrubs, annuals, and a gazillion roadside weeds.
Although letting your personal weeds flower for honey bees is a nice idea, the net benefit isn’t great. Perhaps if you curated lots of blooming weeds in August, I might think differently, but May is abundant with flowers of endless variety. Save your neighbors the angst and just mow your lawn, at least in spring.
Tall grass is a problem for ground-nesting native bees
Did you know that most solitary bee species live underground? Truth! About 70 percent of them. And these bees want bare ground without mulch, weeds, grass, or too much shade. I often see them nesting along sidewalks or curbs where the ground shows, or along the bare strips between lawns and shrubbery. These areas are perfect for ground bees like diggers, miners, and sweat bees.
But when you stop mowing your lawn and the tall grass blocks the sun in those earthy areas, the bees are not happy. Not only is home hard to find beneath the tangle of weeds and grass, but the earth stays cold and damp. These bees are seldom short of forage in May, but in suburban areas, they are often short of nesting sites. No Mow May makes it worse.
You may think you don’t have those types of bees in your yard, but you do. Many folks simply don’t recognize them as bees, mistaking them for gnats, fruit flies, or tiny beetles.
Tall grass overwhelms ground-hugging native flowers
I admit my lawn is not acceptable by suburban standards. It’s full of things other people poison, such as yellow wood violets, wild strawberries, and low-growing rock purslane with mini magenta flowers. These graceful plants grow along the edges of the lawn where the grass transitions into trees. Although they are barely noticeable, ground-hugging perennials will thrive if you don’t let the lawn grasses shade them out.
I leave them for the pollinators, mowing over their heads as needed. Although I can’t see the plants from a distance, little bees and small butterflies visit frequently, as long as the grass doesn’t get high enough to hinder their flight.
An uncut lawn gives invasive species a head start
Although minuscule native plants can’t compete with unmowed grass, bulky invasives can. Things like prostrate knotweed, broadleaf plantain, crabgrass, goosegrass, and quackgrass move right in.
Once aggressive weeds get a foothold, people do more than mow on June 1. They follow up with herbicides. And herbicides, like all other pesticides, kill living things. Anything that kills living cells surely has effects we don’t know about. If you need to follow No Mow May with glyphosate spray, then it’s better to just keep mowing.
Nothing makes ticks happier than long grass
I live in tick heaven. They love it here, jumping from tall grasses onto anything that walks by, including people, dogs, deer, goats, and cats of all sizes. Depending on where you live, ticks carry a variety of nasty diseases not limited to Lyme and Rocky Mountain spotted fever. If you decide to stop mowing, be safe by monitoring yourself, your kids, and your pets for ticks and other unfriendly insects and arachnids.
The sources I consulted about tick control all recommend keeping lawns cut short. Ticks like grass that holds moisture, so for them, the longer the better.
The unintended consequences of tall grass
If you are living in an area of hot dry weather, beware of the special wildfire hazard a tall-grass lawn can become. Once the tall grasses turn dry and crispy, fire can spread like lightning.
In an online discussion of No Mow hazards, people also mentioned mowing over garden hoses and kids’ toys that nestled in the grass, and tripping over lawn sprinklers. One family exposed a pack of rats snuggled against their foundation, and several mentioned an uptick in mouse sightings.
Then, too, several explained the difficulty of mowing tall grass after a month of growth. One man said he had to clear the mower blades every few feet, using up “all the time I saved by not mowing in May.”
Pollinators need your help, but…
No Mow May has its attractions, especially if you don’t enjoy mowing. But there are many ways of helping pollinators beyond letting your grass grow tall in the flower-filled month of May.
You can start by planting garden flowers that bloom throughout the year, especially in the dry months of July, August, and September. Give pollinators some bare ground, a source of water, and a sanctuary free of pesticides. Give them sun and shade, standing stems, places to nest, and places to hide. Try adding a bee house, a bird bath, and a hummingbird feeder to round out your pollinator attractions.
And if you really want to give up mowing for a month, try September. A fall bloom of dandelions could be a boon to honey bees, bumble bees, and other late-season species. Taken together, your pollinators will be better off if you follow common sense instead of following the crowd.
Rusty
Honey Bee Suite
See also:
The surprising downside of #NoMowMay
No Mow May? Good intentions, bad approach, critics say
New research has scientists rethinking the popular No Mow May idea
No Mow May Could Backfire: Here’s Why
The Science Against No Mow May
Is frequent swarming disastrous for bees, or a miracle?
About Me
My love of bee science is backed by a bachelor’s degree in Agronomic Crops and a master’s in Environmental Studies. I have written extensively about bees, including a current column in American Bee Journal and past columns in Two Million Blossoms and Bee Craft. In recent years, I’ve taken multiple courses in melittology and made extensive identifications of North American bees for iNaturalist. My master beekeeping certificate issued from U Montana. More here.