Why naturalists are encouraging homeowners to keep their lawns 'messy' this spring

The No Mow May campaign started in the U.K. to help protect plants, pollinators

Posted: May 12, 2022
Last Updated: May 12, 2022

The No Mow May campaign is asking Calgary residents to hold off on mowing their lawns this month to allow plants and insects to thrive. (Mindi Summers)

When you think of an esthetically pleasing lawn, images of weed-free, bright green grass, that's evenly spread and cut may come to mind. 

But some naturalists are asking Calgary residents to reconsider that vision in favour of a more natural look.

They're encouraging people to park the mowers, edgers and trimmers this spring, and let the yard get a little unruly.


"Messy lawns are good lawns," said senior instructor of biological sciences at the University of Calgary, Mindi Summers. She's also an invertebrate researcher and is involved in the school's bee campus initiative.

"A messy lawn, when you look at it, you should think there's lots of life living here and there's healthy soil, and it's really helping to support all of our wildlife neighbours, as well as prevent storm water runoff."

There are more than 330 different species of native bees in Alberta, according to Summers. In Calgary, there are 199 different types of bees and at least 17 confirmed species of bumblebee (seen above). (Mindi Summers)

Summers is a supporter of No Mow May, an initiative started by U.K. charity Plantlife. It encourages residents to not mow their lawns during the month of May to help support the growth of native plants, which in turn help pollinating insects like butterflies, beetles and bees. 

The message comes as beekeepers and honey producers in Alberta report some of the worst winter mortality rates they've seen this year. 

"It helps us change our attitudes toward what we see as beautiful in terms of looking at other people's backyards and across our neighbourhoods," she said.

"It's incredible the things people will find in their yards, like orchids or really rare plants that they wouldn't expect — wild strawberries, onions, all sorts of different plant biodiversity that comes up."


Mowing the lawn not only prevents some native plants from growing, but can also disturb ground-nesting bees who have yet to emerge from their winter slumber.

"A queen will overwinter in the ground," Summers said, adding that they surface sometime in the spring.

"If anyone does find a bee overwintering in the ground, you'll probably notice that they're not moving. They're just in a dormant state, and so we just encourage people to put them back where you found them … you've just found a bee that is not ready to come out and start pollinating."

A bristle fly sits on a flower. (Michaela Seal)

Some insects and larva will also overwinter in twigs or branches, Summers said, so leaving those alone for the spring can be helpful, too. 

In the end, it'll all benefit your garden, said Ken Fry, an entomologist at Olds College.

"Boy oh boy, do we need those bees to make those fruits and veggies come alive," he said.


As part of the campaign, the Nature Conservancy of Canada (NCC) is encouraging people to plant more native species in their yards — things like blanket flowers, saskatoon berries or bearberries.

Although many consider them an eyesore, dandelions can also contribute to a healthy yard.

Although dandelions are a controversial weed among gardeners, bumblebees have no problem enjoying them. (Ken Fry)

"They do provide early season pollen and nectar for pollinators," said Sean Feagan with the Alberta region of the NCC in an interview with The Homestretch.

"I think diversity is the spice of life and there's certainly room on a lot of different properties to have different types of plants growing."

As an added bonus, if you let your lawn grow an extra few inches in the spring, it helps to keep grass healthier later on, said Fry.

During spring, the base of the plant is still vulnerable from lying dormant in winter, so a low cut could risk damaging it. It's also still pretty cold in Calgary in May.


Butterflies are pollinating insects, along with bees, flies and beetles. (Mindi Summers)

"It's recommended not to mow before the overnight lows get above about 5 C," he said.

"What you're doing is you're ensuring that the lawn gets a good start … even during the summer, you shouldn't be cutting your grass really low, honestly, because it causes drought stress." 

Long grass will also provide shade for insects. Yes, that could mean mosquitoes, Fry said, but he argues Calgary doesn't see a very high mosquito population.

"It's not as bad of a trade-off [in that you're] providing a habitat for those beneficial insects to get out of the heat."

Although most naturalists seem to embrace the idea of No Mow May and its benefits for our environment, the campaign may need an Alberta-specific refresh, Summers said.

"Here in Calgary, we might want to also promote a bit of a No Mow June because that's when we see a lot of our both pollinator bees as well as our native wildflowers coming up," she said.

Drone flies are one of many pollinators working their magic in the springtime. (Michaela Seal)

So if you pass an overgrown-looking lawn at any point this spring, Summers said to consider a change in perspective.

"A lawn is beautiful because it supports biodiversity and we can really celebrate everyone who's kind of taking initiative to support biodiversity in their lawns and backyards."

With files from Ellis Choe