There are benefits to having grass in parks and residential properties. When taken care of, grass becomes a natural carpet on which one can easily rest, play or walk. But to keep Poa pratensis green and thus in a juvenile state requires an investment of energy, an amount that is exaggerated by our questionable habits.
The typical high maintenance option involves buying synthetic fertilizer for spring and autumn applications, herbicide for weeds and pesticides for grubs. Some hire a company to drive around the neighbourhood to periodically spray lawns with the necessary concoction. To avoid the nuisance of a long electrical wire, people buy gas-powered mowers. And to prevent leaves and tree seeds from accumulating on lawn, blowers come to the rescue.
Even if people with such habits are aware that making fertilizer is an expensive process partly because nitrogen does not spontaneously react with molecular hydrogen; even if they know that some fertilizer-pellets inevitably get sprayed onto sidewalks where they damage concrete, induce diarrhea in dogs and end up in storm drains and eventually into waterways and contribute to eutrophication; even if they suspect that the use of pesticides has ecological consequences; even if they are aware of the carbon footprint of synthetics and mowers and of the noise pollution of blowers, there is a possibility that they persist with their habits because they believe there is no alternative.
But when there is a will to change, there are always other options. One reason people turn to mass-maintenance techniques is that they plant more grass they can handle. City parks or residents can instead plant more trees, shrubs and cultivate gardens, which is what we did with 2/3 of the lawn we originally had in our backyard. I never spray any of our fruit trees or apply any pesticides to our garden. Instead of synthetic fertilizer, we rely on a combination of household compost and composted chicken manure. Grass cannot be eaten, but from July to October we have not needed to buy any tomatoes, garlic, parsley, basil, thyme or Swiss chard. We still have frozen cherries from our tree and we’ve also enjoyed arugula, fresh beans, onions and Mexican peppers, most of which were grown from seed.
A city bylaw prevents us from cultivating the front yard, but I manage to sneak in some oregano and bird’s-foot trefoil. They require less water and nitrogen than Kentucky bluegrass and displace weeds. Since our city does not use pesticides on the grass between our sidewalk and road, dandelions, crabgrass and plantains find their way into our property. But I just pull them out with a hand tool. As an alternative to synthetic fertilizer, mulch from the electric mower is left on the lawn so that essential elements like nitrogen, phosphorus and potassium can be recycled. To supplement the lawn with more natural fertilizer, we let the dog pee on it and then immediately add collected rainwater to prevent “burning”. Due to their carnivorous diets, dogs’ urea is highly concentrated so it easily creates a hypertonic solution that needs to be diluted. In the spring the melting ice and snow takes care of that. Spots that don’t receive their share of dog pee get coffee grounds, which also keep the lawn green.
Abating the effects global warming involves more than reducing the use of fossil fuels for transportation and electricity-generation. They only account for a combined 45% of greenhouse gases(see pie chart below). Just about everything else ranging from reproduction to growing grass and food also impacts climate change. To solve the problem, regardless of the field of human activity, green or technical, we have to conserve and act more benignly towards ourselves and our surroundings.