How to Make Your Lawn Eco-Friendly
The "Ideal" Lawn
A well-manicured, tidy green lawn with dense, green grass and no "wild" growth is often perceived as the ideal look for suburban homes. Even in the countryside it is common to see sprawling green lawns that have been sprayed, watered, and frequently mowed to achieve a consistent, soft, carpet-like appearance.
Maintaining these "ideal" lawns requires money, time, and constant attention. This also comes at a cost to the local environment, through inefficient water use, fuel and emissions, and the loss of productive habitat for wildlife.
The Environmental Costs
In the United States, where water is very cheap, nearly 9 billion gallons of water are used every day for landscape irrigation, and lawns are considered the largest irrigated "crop" in the country. Up to half of this water is lost as runoff, carrying with it the residues of any fertilizers and pesticides that were used on the lawn. Many people there will water their lawns during the hot, dry parts of the day, when much of the water is simply lost to evaporation rather than soaking into the soil.
Lawns tend to have compacted soil, since they are frequently rolled over with the mower, and walked or played on by children. The varieties of grass used in most lawns have shallow roots that do not reach deep into the soil to prevent compaction and help retain water. This means that rainwater and sprinkler water are more likely to simply run across the ground and down into the storm sewers instead of soaking into the soil. Grass also does not contribute to soil health in terms of nutrients, as opposed to something like clover (often considered a weed) that actually helps fix atmospheric nitrogen into the soil.
Habitat Loss and Biodiversity
A monoculture of grass is little more use than a desert to the local wildlife. A natural meadow is composed of many different species of plants, which provide food and shelter for insects, birds, and other wildlife. In contrast, a lawn is typically densely planted with one species of grass that is frequently mowed, and cannot provide much food or shelter to insects.
Lawns eliminate biodiversity, which leaves them highly susceptible to attacks from "pests" and "weeds". Pests and weeds are simply nature's way of fixing what it perceives as a problem. Low diversity equals a high risk, as any stock investor is well aware. Having just one species in a large area means there is a greater chance that the whole area will be devastated by a single disease or other problem. Nature tries to eliminate this risk by increasing diversity, much to the frustration of the homeowner who just wants a green lawn.
Since nature will work hard to fight against the "perfect" lawn, many chemicals are used to suppress it and maintain that unnatural carpet-like appearance. Fertilizers are used to create lush growth, pesticides are sometimes used to eliminate things like grubs which eat the roots of grass, and herbicides are used to fight off weeds. All of these chemicals are at risk of running off into the storm sewers with the rain or sprinkler water, and their effects on local ecosystems beyond the lawn itself can be harmful. Even organic, natural fertilizers can be a problem when they leach out with the water into local water bodies, where they add excess nutrients to the water. This can create a condition known as eutrophication, which causes excess algae or other aquatic plant growth. The algae or plants then die, and their decomposition robs the water of oxygen, creating anoxic conditions that can lead to fish kills and other problems.
Besides products that are directly applied to the soil, lawn maintenance often requires the use of fossil fuels as well. Besides the actual lawn mowing and weed trimming machines, there is also the fuel used in producing and shipping the various products mentioned above.
Do you allow weeds in your lawn?
What are the alternatives?
We absolutely do not need to completely surrender our lawns back to nature in order to make them more eco-friendly. With a few small adjustments and a slight change in perspective, we can still have nice green lawns, with fewer inputs and much less work than those perfectly manicured (and excessively hard working) neighbours.
1. Coming to terms with weeds
A "weed" is just the word we use for plants that are in the wrong place. So the common perspective is that any plants in a lawn that are not grass are weeds, even if, in another location they might be be beautiful wildflowers or useful herbs.
If you mow your lawn regularly enough, you can still have a dense green carpet, even if it's a mix of different species. With a community of plants, you will have different plants that have different function. For example, if there is clover in the lawn it will help by fixing nitrogen from the air and putting it in the soil. Clover flowers are also great for supporting beneficial insects such as bees.
Other plants have deep roots and will reach down into the soil, drawing up nutrients that other plants like grass can't access. When those plants die back in the winter, they release those nutrients back into the upper layers of the soil and help support the other plants around them.
Coming to terms with weeds is all about perspective. If we can learn to see the many benefits of biodiversity, we will come to appreciate that each plant has a special role in the ecosystem. Just remember that your lawn is part of nature, not separate from it. Working against nature is always more work than cooperating with it.
2. Water Use
Weeds are tough, anyone who has tried to eliminate them is well aware of that. What many people have not have realized is that this also means they can let you have a nice green lawn in the heat of summer when your neighbours are desperately dumping water on a crispy brown patch of dead grass. Native meadow plants ("weeds") have evolved to live in your area, and they know how to handle it. I have never watered my mixed species lawn, and it stays green throughout the summer, regardless of the conditions.
If you do decide to water your grass, please don't do it in the middle of the day. Most people know this, yet still so many people have their sprinklers going in the heat of the afternoon with the sun blazing, and it doesn't make any sense. On a hot day a lot of that water will evaporate before it ever gets a chance to sink into the soil. Water at night, and only when necessary.
Another issue with watering is the runoff. A lot of water is wasted when it does not get absorbed into the soil and runs off down the street instead. If you have a mixed species lawn with a varied, deeper root system, it will absorb more water and prevent more soil erosion than a dense sod lawn with compacted soil under a shallow root system.
If we want to have a compromise between the green suburban lawn and a healthy biodiverse meadow, we will have to mow regularly (not more often than a regular lawn, though). Most neighbours and even bylaw officers will complain (or fine you) if you let your lawn go completely wild and free, so mowing is something you can't really avoid unfortunately. However there are a couple of ways to come to terms with this. Note that some plants, such as plantain, will naturally grow low to the ground and you might find that your particular lawn community actually lets you mow less often than you would with grass only.
If your lawn isn't too big, consider using a manual push mower. I have been using one in my city lawn for the last five years, and it has worked great. Yes, it is extra work, and yes I sweat when I use it on a hot day, but it's a nice way to get some exercise without having to dedicate extra time to it. It's a lot more peaceful than a roaring motor, and it gets the job done without breakdowns, fossil fuels, or dangerous whipping blades. For a bigger lawn, an electric mower is something to look into.
Mowing does have the benefit of keeping your "natural" lawn more dense and green, and it will prevent most plants from going to seed and spreading over to the neighbours who might not be as eco-conscious as you are.
Another great benefit of a biodiverse lawn is that it has the potential to become a self sufficient community over time, and it will not need inputs from you. You won't have to worry about fertilizing if you have clover in there adding nitrogen, or plants with deeper roots (such as dandelions), that pull up other nutrients from the deeper soil and give them back when they die.
When you mow your lawn, don't pick up the clippings. If your mower leaves them in dense rows instead of scattering them, you can go back with a rake and spread them out a bit so they don't smother the plants underneath them. This will naturally add organic matter back into the soil, and it will cover up any bare parts of the soil and act as a mulch, thus also helping to conserve water.
If you have broadleaf trees on your lawn, you're lucky! You have free fertilizer falling from the sky. Trees reach deep into the soil and pull nutrients up from below. In the fall, they draw back some of that nutrition before the leaves fall, but those leaves are still valuable and will break down slowly into the soil, helping to feed the important microbial and fungal communities and naturally fertilize the soil. Simply run over them with the lawn mower to help them break down faster (and not create a carpet), and leave them on the grass to decay.
5. Beneficial Plants
In his book Bioshelter Market Garden, Derrell Frey writes about alternative plants that can make more sustainable lawns. He suggests, for example, seeding the lawn with a thick planting of yarrow or creeping thyme, which will be soft and dense if mowed regularly. In more cool, shady areas that are not trampled too much, mosses can be added into the mix. He recommends American pennyroyal or peppermint in areas that are typically wet, such as near the downspout on your house.
Dandelions have become a a mortal enemy of many homeowners, but they are a great benefit to the lawn ecosystem. One thing to notice is that dense monocultures of dandelions tend to happen on lawns where people have worked the hardest to keep out weeds. Ironic, isn't it? You just don't see dandelions filling up naturally established meadows. They have pushed their way into our lawns so easily because they are early colonizers, which means they see what nature considers a "disturbed" area, and they rush in to start preparing the area for the succession of a new ecosystem. This also goes for thistles, clovers, and other early successional "weeds". If the lawn is already filled with many different species, there may still be dandelions, but there will be fewer than in a monoculture grass situation.
The dandelion's early flowers attract and feed beneficial insects such as bees after a long winter, and their deep taproots draw up nutrients from the soil. Children also love to play with them!
There are many small, attractive flowers that can be included as well. Find out what is native to your region and choose flowers that are low to the ground and can survive mowing, such as violets.
Go with the flow, not against it
Nature has a system that works. Why fight it? A sustainable lawn is naturally less work than an unnatural monoculture. In my case I have never watered, fertilized, or even seeded my lawn, and it has always stayed dense and green, even in harsh conditions. It's full of life, and helps bring beneficial insects into the rest of my garden, and the gardens of my neighbours around me. If we view our lawns as ecosystems instead of manufactured carpets, we can cooperate with nature, save resources, and enjoy natural beauty right at our doorstep.