The City of Cornwall is undertaking some concrete actions in May to help wild pollinators throughout public and private greenspaces.

No Mow May will see the City not enforce Section 3 of the Yard Maintenance By-Law 2013-212 as amended, from May 1 to May 31. It allows for property owners to have all grass and weeds on their properties to grow more than 15 cm for the month of May.

In addition to increasing food sources for pollinators, not mowing grass in May also prevents disturbance of overwintering insects and amphibians that may be burrowed or hiding in leaves and lawns. It should also be noted that over 80 per cent of all flowering plants rely on pollinators to produce seeds.

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To view a summary of No Mow 2022please click here.

What’s the Buzz with No Mow May?

The City of Cornwall waived section 3 of its Yard Maintenance By-Law 2013-212, as amended, for the month of May which allows residents to grow out their lawn longer than the usual set limit.

The City’s By-Law Services recognizes the ecological importance of No Mow May and offer an opportunity for residents to reconsider their yard maintenance practices during the month of May. The City continues to become a more sustainable city, recognizing the importance to be environmentally conscious and the need to protect and improve biodiversity by implementing sustainable initiatives.

The City is encouraging residents to help protect pollinators during the month of May. Pollinators, including bees, butterflies, bats, and birds rely on the blooming of plants and flowers for nourishment and protection during the colder temperatures. As the days start to warm, pollinators emerge out of hibernation in search of food that is scarce, as vegetation is just starting to bloom. However, not all insects have fully emerged yet.

Some species may still be in hibernation due to fluctuating weather and could be hiding in logs, twigs, and leaf litter commonly found in our yards. The concept of No Mow May is to offer pollinators a chance to emerge from hibernation before mowing the lawn, to give them the first food source of the season that is harder to find this time of year, as well as provide shelter and protection during the colder days and nights of the month of May. This is also beneficial to birds as the assorted vegetation provide them with their varied needs for food and provide them with additional shelter.

There is currently a worldwide decline in bee and insect population due to numerous variables including climate change, habitat loss, pesticide use, and invasive species. Many ecosystems are eradicated during the construction of commercial or industrial sectors which minimizes the habitats of our pollinators. Climate change causes changes in temperature and precipitation, affecting hibernation patterns and blooming patterns of plants.

Insects emerging from hibernation early due to warmer weather will face difficulty when foraging for food, as many plants and flowers have not yet bloomed. This will cause plants to struggle as they will be pollinated later, and insects to struggle as they will be missing out on food sources.

Pollination is the transferring of seeds from one plant to another to germinate flowers. This process is done by species such as bees, birds and butterflies landing on a flower for nourishment who pick up these seeds from the pollen, and who travel and land on a different flower, eventually dropping off the seeds and fertilizing the new flower.

This process is beneficial for the plants who can now bloom, and for the pollinators who receive nutrients. Plants and vegetation are especially important for our ecosystems, and it is important to provide for them and for our pollinator friends as each species contributes to our region’s biodiversity.

No Mow May Myths

Myth – No Mow May increases tick populations.

Fact - Scientific research indicates that milder weather is responsible for the increase in tick population and habitat spreading. They are now able to survive winter. Studies show that No Mow May does not increase tick populations since lawns are probably too dry for the species. Blacklegged ticks (lyme carriers) require 100% humidity for at least part of the day to thrive. The research concludes that ticks found in lawns are typically associated with adjacent woodlands and since they cannot jump, they attach onto whatever passes by. An article published in the academic publication Ecosphere Journal in 2016 stated that ticks are more attracted to “woodlands, particularly in urban and suburban areas, that consist of small forests with mature trees, understory shrubs and leaf litter […].” To help prevent the spread of ticks into urban neighbourhoods, check your clothes (and your pets) when leaving wooded areas or trails.


Myth - Now Mow May increases airborne pollen.

Fact - Research shows that during May 2022 pollen was high across the province of Ontario. The vegetation that generated the most pollen was pine, fir, and spruce; grass had a moderate count; and pollen from weeds and other plants was low or non-existent. A 2019 article in the academic journal British Ecological Society titled Mowing urban lawns less intensely increases biodiversity, saves money and reduces pests claims that reducing the intensity of lawn mowing in urban spaces does lead to the “reduced presence of allergy-triggering weeds,” such as ragweed since the species is able to “colonise disturbances caused by intense mowing.”

Artwork winners

In collaboration with The Cline House Gallery, the City Cornwall organized a No Mow May sign art contest for spring 2023.

Participants were to submit a piece reflecting the No Mow May theme in the material of their choice. The winning entries were each featured on twenty-five No Mow May lawn signs and are currently being displayed in the community.

Congratulations to our winners:


A photo with all of No Mow May's winners.


Before you mow in May…
  1. Walk around your lawn and look for signs of nesting wildlife. Rabbit nests are often tucked into the undergrowth of other vegetation. They appear as regular dried patches of material and dirt. If you happen to see a heap of grass, look under it to be certain it isn’t a rabbit nest. Keep a watchful eye out at dawn and dusk for active rabbits.
  2.  If you find a rabbit’s nest…Place a protective barrier around the nest with enough entry space for the mother rabbit. Mark the nest as a reminder to leave enough space when carrying out lawncare activities. Keep in mind that mother rabbits don't want to attract predators to their babies, so they mostly leave them on their own, hidden and camouflaged. Mom will come back a few times a day, usually between dusk and dawn, to feed the babies. 
  3. Cut your grass in stages. It’s best not to go from No Mow May back to your old lawn in one cut because it could kill your grass.
  4. Mow at the highest setting. This allows low lying flowers to continue to grow and decrease re-flower time for those that are mown.
  5. Keeping your grass at the maximum allowed length has benefits. Cutting the grass too short damages root growth. Some grasses have different heights where they grow best. Leaving 1/3 of a leaf-blade length can result in the best looking full-cover lawn.
  6. Reducing the amount of fertilizer used promotes better aeration for growth.
  7. It’s ok to be somewhat lazy with your property; a manicured lawn is a desert for pollinators and most wildlife. A small pile of twigs makes a great home for pollinators. Leaving a patch of ground dry, unmulched and uncultivated is beneficial for the native bees that nest underground. All bees need a source of water with a perch. Offering a muddy spot with stones helps them out!

Frequently Asked Questions

Who will this benefit?

No Mow May will benefit pollinators such as bees, butterflies, beetles, moths, bats, and birds who rely on flowers and plants for food and shelter and who sometimes need extra time to come out of hibernation. This will also be helping flowers and other plants who rely on pollinators to bloom and reproduce. It will also benefit other communities such as rabbits, squirrels and ground-foraging birds who also rely on plants and flowers for food and shelter, but also for habitats and nesting grounds.

Photo by Cornell University.

No Mow May will also benefit residents by saving time and energy. Mowing less frequently will reduce the amount of air pollution created by the fuel, which will also decrease the resources going into purchasing gasoline. Lawns will also become more resilient to drought when decreasing the number of times you mow. This will ensure that lawns retain their moisture, ultimately reducing the number of times you need to water it. This will save on time, labour, and water costs. Along with saving time and resources, letting the lawn and plants grow uninterrupted brings a vibrant and colourful beauty to your lawn (and it smells nice). You may even learn a thing or two about it and the species it hosts.

What other Municipalities are participating?

No Mow May is a global initiative and is supported by other municipalities in Canada, including Kingston, Sudbury, East Gwillimbury, and 1000 Islands. Quebec City has created a similar program called, “The Dandelion Challenge,” and North Vancouver has created “The No Mow Meadow Project.” Both projects bring forth the same approach as No Mow May, with residents delaying mowing their lawns to give pollinators access to more food sources and to promote the growth of their population.

See what some municipalities are doing to promote the movement.

What are other municipalities doing to help the pollinators?

Guelph – “Pollination Guelph”. Guelph displays gardens that are planted with shrubs, grasses and flowering perennials that offer food (pollen and nectar), nesting and overwintering sites for pollinating insects. The seeds and berries also attract birds and small mammals to the gardens.

Find more Information here: Pollination Guelph

Toronto – “Pollinator friendly garden”.  Toronto is enhancing and protecting pollinator and small animal habitat in natural and urbanized areas by planting native plants, trees and shrubs.

Find More Information here: How to Help Wild Bees & Other Native Pollinators


Ottawa – “Pollinator Steward Certification”. Ottawa is helping citizens take a more active role in pollinator conservation. The program involves educating participants about pollinator ecology, habitat creation, and public education strategies.

Find More Information here: Pollinator Steward Certification

How tall can my grass be?
During the regular months of the year, grass in the City of Cornwall should not exceed 15 centimeters (6 inches) in height (see the Cornwall’s Yard Maintenance By-Law or Cornwall’s Property Standards). For the month of May, there is no maximum on grass height in order to support No Mow May.
When will I be able to mow again? 

You can mow anytime in May, that is up to you as there is no signed contract. As long as you delay your first mow, a good time to start mowing again would be when days and nights are consistently staying warm, and the pollinators no longer need to shelter themselves from the cold. A safe time to start would be end of May.

The Yard Maintenance By-Law will be enforced again starting the month of June and your grass cannot exceed the height of 15 centimeters (6 inches). Residents are encouraged to take the gradual approach when starting to mow. This will give the pollinators a chance to realize that the area is not the best place for them anymore.

The gradual approach will also prevent the lawn from being damaged. Before mowing, it is important to check the lawn for nesting animals like rabbits or for birds that may have fallen out of trees.