How Green is Your Grass?
June 25, 2012
By Matt Palmer
Yesterday, I read this article in The Globe and Mail, “The Environmentalists Case for Well Manicured Lawns” that got me thinking differently about my grass. The article challenges the assumptions that urban lawns are a waste, and tax on the environment.
A year and a half ago we moved to a new home. We felt downsizing a bit would be a good thing, we wanted to be closer to our children’s school so that they could eventually ride their bikes, something our oldest son now does, and we wanted a bigger yard.
And, we got a big yard, something that is hard to find in newer neighbourhoods. The extra yard space is great for two young boys and a big dog, but I was under the impression that large grass spaces were counter-productive ecologically. According to the Globe and Mail article:
Greenpeace has declared that “a lawn is an unnatural ecosystem,” advising homeowners to “plant flowers, trees, bushes, ground cover and vegetables instead of grass.” The Sierra Club laments that Americans use 100 million pounds of pesticides and herbicides a year, and that “some of these chemicals leach into the groundwater, pollute the air, and get onto the skin and into the mouths of our children, pets, and other creatures.”
As we have young boys and a boisterous chocolate lab, we have been cautious about using chemicals on the lawn. The crab grass, dandelions, and thistle weeds now mock me as a result.
In our previous home I was the water czar, not wanting to waste the precious resource just for the sake of having a green lawn, and the lawn got its revenge by turning brown and dying. At least I didn’t have to mow it every week after that.
Now we water on a regular basis in the summer, but I admit pangs of guilt every time, because I still feel like we are wasting water. But, maybe not as much as I think.
Then there is its cooling influence. When the water drawn in by grass roots is released by its blades – the process called transpiration – it has an effect something like what happens when a human sweats. A Brigham Young University found that turf grass is about 7 degrees cooler than bare ground and 18 degrees cooler than asphalt. Plant more, healthier grass in cities, Mr. White says, and you can help counteract the heat-island effect that makes city dwellers suffer in summertime…
…The water that helps it grow, Mr. White says, isn’t wasted at all. It is transpired into the air or filters through into groundwater and flows into rivers and lakes.
Our goal for our yard is to build a nice vegetable garden, and plant a few more trees, making the space more functional ecologically. The extra grass space even wore out my eight year old lawn mower. I recently wrote about my adventures in buying a new “zero emissions” mower.
Reducing grass space in my yard would produce a few benefits: I would not have to spend as much time mowing, and we would produce some tasty vegetables, in the process teaching our sons about gardening. But, making the transition purely for better carbon sequestration may not be the reason to do it.
Partly because of its stable roots, grass absorbs and holds climate-warming carbon. One study found that even a lawn given minimal care can take in as much carbon as an equivalent forested area. Another part of the reason is the sheer number of shoots that an average lawn produces: six per square inch and 85 per square foot, or about 8.5 million in a 10,000-square-foot plot. Using satellite data, a scientist for NASA’s Earth Observatory estimated that if Americans left their grass clipping on the lawn to decompose, as many homeowners now do, U.S. lawns could store 37 billion pounds of carbon a year.
Whether you agree or not with the Globe article, it provides another example of how important it is to challenge assumptions and deeply held beliefs. This is not to say we should be bulldozing trees and planting more grass, but rather to consider that urban lawns may have a place, use of pesticides aside.
While I admit to liking a nice lawn, I also like the idea of seeing more urban spaces being used for food production. For families struggling to make ends meet, a small garden may not make a huge difference, but the difference can be quite tangible, leading to an inspired wider community.
We will still move ahead with our plans to transform a portion of our yard with a garden and more plants. And my boys are having a great time exploring the world within the grass.
Any lawn-care worker knows that grass is a haven for every kind of bug – grubs, ants, spiders, crickets, grasshoppers, mites, earthworms, beetles – not to mention the millions of microbes that feast on the root thatch and grass cuttings. A healthy, well-cultivated lawn is especially hospitable, supporting 25 to 40 grubs per square foot, compared with five to 10 for one that’s unhealthy.
I have a greater respect for my lawn now, and its role as a backyard ecosystem. I cannot wait for the day when I can hand the lawn mower over to my sons and help them gain that respect as well.
Category: Blogs, Environment
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