Grow don’t mow

While listening to a Blue Jays baseball game recently, I was struck by an ad from the  Canadian Wildlife Federation that encouraged people to “grow, don’t mow” their lawns.  The goal is to encourage pollinators, which like many insects, are in serious decline.  The idea of “grow, don’t mow” is not new many groups have been championing the replacement of lawns for some time.  However, it always seemed a bit of a fringe activity- not accepted by the mainstream, and not supported by the lawn care industry.  Yet here, on prime time television, there was an ad for “grow, don’t mow”.  Could it be that this idea is becoming more mainstream and more widely accepted?


The goal of the CWF “grow, don’t mow” effort is to encourage pollinator  pathways  across Canada as a way of sustaining the native insect population.  The initiative is targeted at homeowners and “rights of way” managers such as municipalities and utility companies. The CWF estimates that there are about 6.2 million lawns in Canada. Converting just one-quarter of each lawn would equal around 14,400 hectares of habitat for pollinators!

The decline of insect and pollinator species create immense problems.   A recent study published in the journal Biological Conservation compiled the data from 73 studies across the world to paint a picture of insect diversity.  41% of all insect species have declined over the last decade.  This affects the pollination of our food crops and native plant species. It also impacts species such as reptiles, fish and birds who rely on insects for food.  The loss of insects is a downward spiral that will affect the health of many creatures on the planet.  Professor David Goulson of the the University of Sussex  states:” It should be of huge concern to all of us, for insects are at the heart of every food web, they pollinate the large majority of plant species, keep the soil healthy, recycle nutrients, control pests, and much more. Love them or loathe them, we humans cannot survive without insects.” (Plummeting insect numbers ‘threaten collapse of nature’: Guardian 2019)

The causes of the insect decline are varied.  Industrial agriculture, with its use of pesticides, seems to be a major culprit. Habitat loss and a global warming are other factors.

What to do- a simple plan

In order to encourage pollinators and other insects, there are some simple things that can be done.  More intensive strategies, such as converting your entire property to a native meadow, are also options,  but sometimes it is best to start with those options that require least effort.

The simplest thing that people can do to encourage insect populations is to reduce the frequency of lawn mowing.  Mowing every 4 weeks instead of every week will encourage the growth of plants such as clover, black medic, self heal, and dandelion.  A fascinating article in Plantlife chronicled the experience of the UK, where homeowners were encouraged not to mow their lawns in May.  The results of the effort were amassed by citizen scientists who compiled data on the plants that grew when the grass was left unmowed.  The effort included a National Nectar Score, which measured the total volume of nectar produced by these plants.  The results are astonishing.  Unmown grass supported an average of 400 bees per day from flowers such as white clover, selfheal and dandelion.  These flowers will tolerate the occasional mowing because their stems are able to survive lawnmower blades.  They will resurge after mowing and may even form denser colonies.  The article recommends that people leave a strip of their lawn totally uncut, to encourage taller plants to grow.

Not only is the effort of no-mow more conducive to pollinators, but it also reduces greenhouse gas emissions from lawnmowers.  Running a gas-powered lawnmower for an hour is the equivalent of driving 300 km.  If lawns are mowed monthly rather than weekly, that is the equivalent of reducing the pollution by 75%.

The disadvantages

Not mowing your lawn for a month may produce  some disadvantages.  

  • Your lawn will be harder to mow if you leave it for a month.  
  • Your neighbours may disapprove of the look of your new lawn. However,  it is an opportunity to educate others on the importance of insects and pollinators!
  • Your municipality may also disapprove, particularly if your efforts are in a highly visible area, such as a front yard.  Again, there is an opportunity for education and lobbying.  You could also confine your efforts to the back yard or less visible portions of your property.
  • There is little hard data on what plants will grow in lawns in Ontario if they are mown less frequently.  We need to compile more data in order to gain more support for the “grow, don’t mow” initiative.  CWF has initiated an INaturalist program that encourages people to monitor the insects on their properties in order to gather more data.

Looking for more information?

Submitted by Sabine Behnk