Your lawn and garden, tools in the carbon drawdown toolbox
During summer, our minds turn to barbeques, picnics, time outside in the warmth of a summer’s evening….and the lawn! You may think you’ve gotta go and dump a bunch of fertiliser and herbicide on your lawn and garden to get it all primed for the social season! Before your finger starts twitching towards the mouse to click and collect that synthetic nitrogen and associated pesticides, let me tell you, there is another way. 

Did you ever wonder that your lawn and garden could play a role in improving your health and in turn, improving the health of the planet? 

Well, it can and healthy lawn care all begins with healthy soil.

The bacteria and fungi in healthy soil will do most of the hard work for you for free  and many of those same bacteria and fungi are the ones that live in your digestive system and on your skin. They have co-evolved with plants and animals and act as a go-between for plants and soil. 

But first, a quick lesson on something called the Soil Food Web:  Here’s a great 5 minute video explaining the process from  Dr Elaine Ingham who coined the term.

As far as we understand the Soil Food Web works like this: 

  • When plants photosynthesise, in addition to peeling the carbon atom off the CO2, and storing some carbon in roots and limbs, they use the rest of the carbon to produce exudates 
  • Exudates are 1000s of different combinations of carbohydrates and proteins which they exchange with the bacteria and fungi in the rhizosphere
  • The rhizosphere is the root zone populated by these symbiotic bacteria and fungi
  • These bacteria and fungi break down the soil’s mineral content (the sands, silks and clays) and the organic content (dead stuff) in the soil, into plant available nutrients
  • These bacteria and fungi are in turn predated upon by protozoa and nematodes who are in turn predated upon by earthworms and arthropods
  • Each time a predation occurs there is a release of plant available nitrogen and other nutrients

Healthy soil
A sample of healthy soil showing good structure

Lawn care and the Wood Wide Web 

Another cool thing which you may have heard about is that some of these fungi create huge networks between each other and the plants and trees. Some call this the “Wood Wide Web” as it is a bit like an underground internet. 

Trees are able to communicate with each other via chemical signals and share resources, all mediated by fungi. Scientists are still trying to understand how fungi are able to exchange chemicals in one direction and water in the other at the same time. It’s mind-boggling.  

Some of these bacteria and fungi play a vital role in terms of your mental and physical well being via something called the Gut-Brain Axis.  As mammals, we have co-evolved with these bacteria for millennia (known to scientists as “Old Friends”). 

Researchers are discovering interesting ways in which these interact with our immune system and play a role in our likelihood to develop autoimmune diseases and modulate our mental wellbeing. 

I also suspect glyphosate (Round Up) has a role to play here as it is used everywhere – we spray loads of it around our gardens and our schools. Last week I saw a lady spraying a tiny weed in the gutter! 

We are told by the likes of Monsanto/Bayer that glyphosate doesn’t affect us humans, because we are animals and the shikimate pathway (the means by which glyphosate works) is only used by “bacteria, archaea, fungi, algae, some protozoans, and plants

This pathway is not found in animal cells. But remember those “Old Friends” in and on us? What are they? That’s right, they are bacteria, protists and fungi! And what are those guys in the Soil Food Web? Yes, those plus archaea, algae and all those other organisms… what do they have inside them? 

You guessed it: fungi, bacteria, protists, archaea… There are plenty of studies in prestigious journals such as Nature pointing to alarming studies like this finding: 

“Glyphosate-based herbicides (GBHs) can disrupt the host microbiota and influence human health.” 

Yeah but, my lawn and garden, dude? 

Pssst! Want to hear a dirty lawn care secret?

That chemical nitrogen you are using on your lawn has a few very dark secrets: only about 30% of applied chemical nitrogen is taken up by the plant – the rest is going into the waterways causing eutrophication, ie dead zones in rivers and the oceans. 

When applied to our gardens and lawns, it is broken down by bacteria and released to the atmosphere as nitrous oxide, a really bad greenhouse gas about 100 x worse than CO2 and it stays in the atmosphere for around 100 years.

 “…the production and use of synthetic N fertiliser account for 2.4% of global emissions, making it one of the top climate polluting industrial chemicals”

According to a new report from the IATP  – and nobody else is talking about it. Did you hear anyone at COP talking about it? Nah-uh! They were, however, talking about methane which is better than not talking about it but I wonder if that is the influence of the tech sector and their rush towards fossil fuel and synthetic nitrogen hungry lab-meat “alt protein”. 

Chemical nitrogen also interferes with our “Old Friends” in the soil in another couple of ways.  It cuts them out of the transaction between the plants doing their job of fetching organic nitrogen and other nutrients so these microbes go to sleep or die and it burns the carbon out of the soil

This destroys the soil’s structure making the soil collapse and become anaerobic (with no oxygen). All the good/beneficial bacteria are aerobes – they thrive in an oxygen-rich environment (good soil is about 25% air). 

As I mentioned earlier, these bacteria when present in the right balance will feed your plants what they need when they need it but also they will actively “outcompete, consume or inhibit” soil and plant pathogens.  

When we burn out the soil carbon we remove much of the sponge-like quality of the soil so you get erosion and the need for more water. Cruelly, synthetic N is salt so guess what, you get an increase in salinity for your troubles. (Plants don’t do well with salt, BTW.) 

Is your lawn and garden addicted to fossil fuels and synthetic chemicals? 

To summarise, the organisms that were doing all this amazing work literally for shit (because that’s the stuff plants have co-evolved with, animal poop) have been sent packing or killed and your plant (the lawn) has become a drug addict

It is dependent upon the fertiliser you deliver.

You have become what ecologists quaintly call a  “more-on gardener”. You must put on more and more synthetic nitrogen to get the same results. 

When you forget to water, it really suffers because there is no fungi in the soil to exchange sugars for water in times of need. Weeds with their long roots spot the imbalance and the free nitrogen and pounce. It becomes the domain of anaerobes and pathogens. 

My friends, there is a better, regenerative gardening way. 

Your lawn 

In environmental circles, lawns are seen as a relic of a very strange part of history. The early industrial revolution. A period when the European landed gentry and bloated industrialists would surround their stately manor house with neatly mown expanses of grass.

The concept has spread throughout the world and is now a symbol of pride. They are of course a completely artificial construct and cannot exist in nature. Maintaining a monoculture has in the past relied on irrigation, chemical fertilisers and pesticides to preserve their appearance. 

However, if lawns are managed in a more thoughtful manner, some say they can be a carbon sink. In much the same way as thoughtfully managed grasslands can be. According to Project Drawdown: Improved grazing can be very good for the land and sequester from one-half to three tons of carbon per acre. 

Basically we can graze our lawns better!

Better? You didn’t know you were grazing them in the first place?! 

You don’t have any cows in your garden so how can you graze and sequester carbon? 

You probably have the closest thing to a ruminant which is the combination of a lawn mower and a compost bin! 

A lawnmower is a grazing machine, albeit not a perfect one. It doesn’t wee  or poop fertiliser but it does the first part well – mostly too well. By this I mean TOO CLOSE. We mostly mow too short which allows the sun better access to the space below the leaves, where the weed seeds are waiting for their chance to germinate. 

Once they germinate under a very short lawn they are up and off to the races whilst your poor lawn is recovering from being cut so short. The roots of the grass have just dumped a whole bunch of exudates in order to stimulate the bacteria and fungi to go and get more food so it can recover. 

The weeds jump up and put their leaves on top and start making flowers before you need to mow again. Also the lawn is now needing more water as you have removed their moisture retention blanket so you water and the weeds – if you listen carefully – are cheering your generosity! 

11 Steps to healthy lawn care

  1. Raise the bar: Lawn being overrun by weeds? Raise the cutting blade to avoid “scalping”. Sorry to break the news to you, but mowing too short to save yourself having to mow so often is a false economy.

    Remember those blades of grass are your lawn’s means of feeding itself. If you keep cutting close, you inhibit the ability to provide exudates for the bacteria and fungi in the soil which take those in exchange for plant-available nutrients. Also, taller grass shades itself and retains more moisture, not to mention deprives the weed seeds of any sunlight to keep them suppressed. 
  2. Mulch mow: In the warmer months use a mulching mower – let the clippings break down on the lawn. It might look a bit unsightly for a few days but if you lay off the chems, the biology will deal with the clippings and turn the clippings into fertiliser and sequester carbon. This is mainly a summer thing though. In Winter if you are still mowing, pop most of the clippings in your compost bin. 
  3. Go native: There are now some native grass species which make for an excellent lawn. I have experimented at home with Zoysia macrantha – it has performed fairly well in summer (it’s a warm season grass). I have not watered it since it was established and I have only needed to mow it 3 times since I put it down over 18 months ago!

    In this time I have grazed chickens over it so you may need to mow slightly more often but not much. It does brown off over winter so an interplanting of some cool season grass species would be an idea here, it’s an ongoing experiment.
  4. Compost, compost, compost: By now, hopefully you know that the single best thing you can do for your garden is applying your own compost (and that it is the best thing you can do with your food scraps if you don’t have chickens).

    So back to the grazing – your compost bin is the rumen (of your ”cow”) and breaks down the clippings if you don’t want to leave them on the lawn – just make sure you add some dry ‘browns’ (leafy materials, twigs, cardboard etc) then once you harvest your compost you can mix it with some sand and apply as a top dressing.

    Compost helps raise the organic content of the soil and add more microbial life. These in turn will outcompete pathogens as well as break down the parent material in your soil and feed it to your lawn in the amounts it requires without the runoff and eutrophication.
  5. Aerate: It’s a good idea to aerate your lawn by either opening it up with a fork or an aeration device to allow roots to go deeper and improve the soil and for the soil microbes to thrive. Do this whilst topdressing.

    Problems happen when soils go anaerobic as I have mentioned above. When aerating, you’re not wanting to disturb the soil profile, just get some air in there and a bit of organic matter. It will improve drainage and lead to happier grass.
  6. Water wisely: in the US between 50-75% of a household’s water usage can be dedicated to irrigating the lawn – probably not quite that here in Australia but we live on the driest continent on Earth so we need to think about what we are doing with our potable water.

    Think about a gray water system. Water only when you notice your lawn needs it. Water deeply to encourage the roots to go deeper into the soil where the temperature is more stable and there is more moisture. Regular light watering promotes shallow roots and vulnerable plants/lawn.
  7. Hand weed: Don’t spray to kill that weed! Think of yourself as a surgeon rather than a carpet bomber. Use a sharp serrated steak or paring knife (a cheapo one from Colesworth does this perfectly), to surgically ‘crown’ it (ie, cut below the growth point) and then cover the tiny amount of bare ground with some turf topdress or compost to prevent other weed seeds in the soil from germinating.

    The roots will rot and feed the soil biology (and store carbon). Do this instead of pulling the weed out – when you pull a weed you bring soil from deep down up to the surface, disturbing all the underground activity – breaking up the fungal hyphae connections and worm passageways and along with it, all the dormant weed seeds which will love the new empty space you have created by pulling the weed. (I could write a post on this topic alone!)

    Using a serrated knife to remove a weed prevents pulling up weed seeds A surgical approach to garden weeds will result in less weeds and improved soil. 
  8. Stop killing stuff: Yes, I know you just want a perfect lawn but the moment you start killing stuff you start simplifying the ecosystem and disturbing the natural balance even further. A pest is nature’s way of telling you something is missing or wrong in the wellbeing of a plant.

    Most of the time that means there’s something wrong in the soil or the environment. Check the suitability of the turf variety to the conditions and the cultural conditions (shade, drainage etc). The moment you spray you are killing non-target species (such as beneficial insects) and you are then going to have to do their job too as well as your own.

    Plus you are introducing a poison into your home environment and whatever is down the hill or downstream. Do you have young children? Do they like playing outside? Look closely before spraying as you may be killing beneficial bugs If you spray these aphids you will be killing the larvae of a wasp that eats aphids.

    Wasp larvae that will eat aphids
    ​​If you spray these aphids you will be killing the larvae of a wasp that eats aphids
  9. Ease off the fertilisers: If you notice the lawn is lacking luster, look for an organic source of nutrition such as an organic-based manure derived one. Plants have co-evolved with animals and particularly their poop.
  10. Mono vs polyculture: Why not embrace the concept of a Mowable Meadow? Whilst it might be a stretch in some more conservative neighborhoods, the local flora and fauna will love it and that in turn will help the rest of your garden with pollination and beneficial insects calling your garden home. It will look really pretty too!
  11. Plant more small flowers: Small flowers like Alyssum, umbelliferous flowers (look like an umbrella) like carrot, fennel and parsley, the nectar is easily accessible so beneficial insects will always have a food source if there aren’t enough bugs to predate upon.

    Then let them go to seed. When people ask me what is the first thing they should do to start a veggie patch I tell them start by planting heaps of flowers, then look to plant your veggies. Sweet alyssum attracts beneficial insects such as ladybugs to your garden and is one of the best plants for attracting and retaining beneficial insects. 

Why have I written this? 

Do I want to look after your lawn permanently? No. Do I want you to be healthy? Yes. Do I want your soil to be healthy? Yes. Do I want your lawn and garden to draw down carbon? Absoil-freaking-lutely! 

Further reading: 

Teaming with Microbes The Organic Gardener’s Guide to the Soil Food Web by Jeff Lowenfels, Wayne Lewis 

Soil by Matthew Evans 

For The Love of Soil by Nicole Masters

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