Inside: Read about the drawbacks to No Mow May for honey bees, native bees, and homeowners, too.
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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.
Honey bees don’t need extra forage in May
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
I backed my love of bee science with a bachelor’s degree in Agronomic Crops and a master’s in Environmental Studies. I write extensively about bees, including a current column in American Bee Journal and past columns in Two Million Blossoms and Bee Craft. I’ve endured multiple courses in melittology and made extensive identifications of North American bees for iNaturalist and other organizations. My master beekeeper certificate issued from U Montana. I’m also an English nerd. More here.
Hello Rusty,
May I provide this article to our local weekly newspaper?
Fred
Fred,
Absolutely! Thank you for asking.
Thank you.
I also leave it in May Rusty, but primarily for baby birds to be fed the extra insects no-mow produces. There is PLENTY here, both in my garden and in surrounding fields and gardens for our buzzers. My sis in law keeps bees, I choose to grow flowers for bees & moths always, and also look after the varied bird population which visits my garden. Essex, in the UK
That sounds unfortunately reasonable. Now I am sad because I found saying “No Mow May!” a lot easier than actually mowing. You’re definitely right about one thing—I need to do some mowing soon, and it’s going to be a horrible chore, with the grass so long. Maybe I shoulda stopped at No Mow April and maybe half of May, tops. Well, I’ll try not to blame the messenger. : )
Well, thanks for that anyway!
As is often the case with new ideas, they tend to be long on impulse and short on execution, dreamed up by people whose hearts are in the right place, but don’t really understand what they are talking about. However, the impulse is a good one: the swaths of yard in the US are green deserts. They suck tons of fresh water, and we douse them with all kinds of chemicals. Add to the amount of time and money spent with constant mowing, and the attendant noise and air pollution, both of which are harmful to human health. I applaud the idea that the manicured suburban yard is an idea that needs to go, No Mow May is a very first baby step in that direction. Just letting those exotic grasses grow is is going to give a huge number of people in this country an ulcer, but it’s a necessary first step toward landscaping with sustainable native landscapes. Frankly, I think this is a good start and it will get refined as we move on. By my way of thinking, we either start to clean up our environmental act, something that everyone can do at their own house, or we will continue tripping down a lawn path that was laid down about 100 +/- years ago and has more to do with perceptions of status and wealth and not much to do with living lightly on a planet in peril. We know better now, so we should do better, to paraphrase Maya Angelou. Native grasses are support structures for native flowers. The stuff growing in the Great American Lawn is not native; most of the plants in the average suburban landscape are not native. (And they are escaping into native plant communities and making a mess.) To me, the end goal in this project is not to end with abandoning the lawn mower in May and resuming in June, but to use it as a transition into landscaping regionally and sustainably with native plants. It will take a few generations for Americans to “get used to” the idea of no yards. It’s going to be a painful, but necessary cultural shift. When we think about ecosystem function we cannot just stop at pollinators, but need to include all of the insects and assorted crawly things that keep this planet going, and whether we know it or not, keep us alive.
Nicely stated, Sharon. One thing I haven’t quite settled on is the issue of native vs. non-native plants. So many of the animal species we try to support are not native either, such as honey bees and us, so I feel there is room for a combination. Some things, like non-native dandelions, can be lifesavers in late season, even for native species of pollinators. It’s a complex subject.
Agree about the ticks – we can’t not mow, we live in mountain woodlands. Too many ticks and I have young children. Lyme disease is no joke.
I plant bee friendly flowers and shrubs on the property but they’re bringing loads of pollen from elsewhere.
Still hoping to hear your thoughts about my split… the queen should be emerging from her cup around now (but I don’t think I should open the box and risk disturbing). I figure we’ll see drone activity by the split in a few days if she’s OK and hardened off for mating flights. No rain forecasted… fingers crossed.
This does not apply to my area where almost no blooms of anything else and not all weeds are out in May. Our bees need every flower they can find in May. I hope this article doesn’t circulate in my area with explaining that it’s for different climate.
Dan,
I did say it applied to North America, although I didn’t go into specific areas. There can be lots of variation. Where are you?
Anything that causes people to question the idea of those useless, manicured lawns and instead appreciate more natural lawns is a good thing, in my opinion.
I understand the downsides stated here, and I know Rusty isn’t defending manicured lawns, but even if “no-mow May” isn’t having a huge benefit for the pollinators, it might have a positive PR impact in at least getting people to recognize that their monoculture, water guzzling, pesticide laced lawns aren’t a great idea either, and maybe…just maybe…it will get a few more people to educate themselves about pollinators.
Mark,
Your argument here is valid. I use a similar argument regarding mason bees and bamboo tubes. I don’t believe bamboo tubes are ideal for bees, especially when the tubes promote a monoculture of mason bees raised in a tiny space where they ultimately share pollen mites and parasitic wasps. The flip side is I’ve seen many people begin to learn about native bees after their tentative experiments with mason bees in tubes. Once that interest is sparked, they grow from there. Many of them become first-rate native bee enthusiasts. So to me, those beginner mistakes can lead to excellent outcomes.
I’m in the property maintenance business- lawn and landscape maintenance- and have had customers ask me (suggest really) a no mow May. I’ve spent a couple of years researching the benefits and watching pollinators at work. Some observations to offer- applying fertilizer to a lawn is not detrimental as long as the rate and frequency of application is not excessive (it usually is if applied by contractors) and NO herbicides and insecticides are used. I have seen all bees, native and honey bees, as well as bumblebees favor low growing native flowers in the lawns over dandelions. They target flowers such as strawberry and violets, but really favor self-heal above all others. My advice is to set the blade height on your mower to 2.75″ on the first cutting and then raise it to 3″ within a few mowings, before going as high as 3.25 or 3.5 in the summer heat. If you have a typical rough grass textured lawn (comprised of a greater portion of rye grass) mowing at these heights will ensure that you will have plenty of pollinator flowers during the season, will keep ticks away, and will have a healthier lawn that is more resistant to drought. One caveat though is to gradually reduce the cutting height in the cooller autumn in .25 or. 5″ increments until the last mowing, just before lawn dormancy is somewhere between 2″ to 2.5″. (For turf health, not within the purview of this conversation on pollinators). I mow hundreds of acres of grass every year. Using this approach will help our pollinators and still provide an attractive lawn.
Wow, thank you for all the specific instructions. This sounds both realistic and doable. Ages ago, when I was an agronomy student, I took several courses in turfgrass management at Virginia Tech, and from those, I remember absolutely nothing. But your comments brought some of it back into my memory, so thank you for that.
This is exactly what we need: more concrete information with the “why” thrown in so we can understand. Perfect.
Strange that no one mentions the environmental advantage of not burning up millions of tons of gasoline that otherwise pollutes the atmosphere contributing to our apparent imminent demise.
Rob,
Bear in mind that not all lawn mowers burn “million of tons of gasoline.” Some you just push. No fuel necessary.
I should of-course have expressed myself more explicitly when posting on your site. I meant: the gasoline and diesel burning mowing machines burning tons of atmosphere polluting fuel every day.
Myself I use a scythe.
I’m pretty sure the No Mow May concept started in the UK – with the intention of addressing the 97% reduction in wildflower meadows over the last few decades here. Obviously the concept and the timing is designed to suit the British climate and this specific aim. Any benefit to pollinators is a bonus.
Sounds like the idea needs to be tweaked for our friends across the pond.
There are no 100% perfect solutions. Yes, I also read that the No Mow May concept began in UK. But there are regional differences in US and even within neighborhoods as stated above that would favor this concept here. The lawn maintenance information offered above is very important also but biodiversity always trumps monoculture ecologically.
In England, people are obsessed with golf green short lawns. I left my lawn in May, it grew to a height of 4 inches. That’s not long! I look at June lawns here and with the hot weather they’ve all gone dry and white. Not good. I happen to disagree with your advice, especially if you live in England.
Peter,
I’m confused. Which part do you disagree with?
I’m making my lawn a little smaller every year just by letting the bushes and trees spread. I have flowering trees, so I think it’s good for pollinators.