As the summer winds down (*sigh), we gardeners must start to prepare for our "big fall clean-up." The end of the growing season usually signifies that it's time to cut back the summer growth, mulch areas with cold-sensitive plants and to harvest the veggie patch for the last time.
And, of course, once the leaves begin to fall, the conscientious homeowner will start digging through the garage for a good rake to gather up their yard waste.
Are you a bit lawn-proud? Hey, no judgment here!
Many homeowners rake up the leaves from their lawn because they believe that leaving the leaves (ahem) behind will suffocate their lawn and leave them with a patchy mess the following year. However, autumn leaves are grossly misunderstood, and underrated. Leaf litter doesn't have to hurt your lawn and can, in fact, provide a host of benefits to your yard, your garden and your local ecosystem!
First, let's look at why leaves shouldn't be raked up and sent to landfill:
Why yard waste in landfills is a big problem
The vast majority of homeowners, once they've raked up their yard waste, will bag it up in paper or plastic bags and drop it at the end of their driveway for collection. This practice may seem innocuous - if not downright traditional! - but it's far from harmless to the environment.
Yard waste that ends up in landfills will begin to degrade, much like food waste. As the organic waste decomposes, methane gas (CH4) is released into the atmosphere. Methane gas is at least 25X worse for the environment than CO2, exponentially better able to trap atmospheric heat than carbon dioxide.
A fifth of all waste sent to landfill is composed of yard waste.
Source: Build with Rise
That's a lot of methane gas released into the atmosphere every year.
Leaf litter, if managed properly, can actually do a lot of good for your lawn and local ecosystem:
Dead leaves are worth their weight in (black) gold
Not only is sending yard waste to landfills an environmental faux-pas, but homeowners who throw away the leaf mould on their lawn are wasting a truly golden opportunity.
While fall leaves that decompose anaerobically (no air) in landfills generate methane, those that decompose aerobically in compost can contribute literal "black gold" to gardeners. Add your leaves to your compost pile, or start a new one with the dry leaves as the "brown" (carbon) materials!
Remember: if the leaves are not completely dry and crispy, they should be added to a compost pile as "greens" (nitrogen matter). Only dry leaves count as browns!
Fallen leaves provide your soil with organic matter & nutrients
While lawns, like any plant, require access to sunlight and oxygen to thrive, they also require nutrients and organic matter to build healthy root systems and withstand disease. As dead leaves decompose, the organic matter breaks down into the soil, feeding the bacteria and insects beneath the lawn surface.
So, how do you balance the sun and air needs of your lawn with the benefits offered by leaf litter?
One tried and true method to have your cake and eat it too is to leave the leaf litter where it is and mow over it as you cut your grass! This will break up the leaves into smaller particles, allowing sunlight to reach the grass, while making it easier for the soil to absorb the nutrient-rich organic matter.
Autumn leaves smother weeds and retain moisture
If you don't mind the look of leaves on your lawn, and you don't feel like raking or managing them in any way, then leaving them where they are is still not a bad idea.
Untouched leaf litter will eventually break down and offer organic matter to the soil, increasing fertility. The coverage dead leaves provide can actually retain moisture for your lawn and smother weeds.
Leaves preserve local wildlife
Finally, leaf litter is a haven to your neighbouring wildlife. Moths and butterflies overwinter in leaf litter - raking up the leaves means you'll have fewer butterflies the following year!
Birds, toads and other critters use leaf litter to prepare for winter, either by nesting and hiding beneath the leaves, or picking through them to search for food!
Not only does wildlife offer entertainment in all seasons, animals and insects are indispensable parts of ecosystems. Birds and toads control pests that may overwinter and chow down on your vegetables, while butterflies and moths pollinate your flowers.
Make the most of your autumn leaves
1) Mow over them to fertilize and condition your lawn
As we mentioned, leaves provide the soil and its microorganisms with a host of nutrients and organic matter. While leaving them in your yard in thick clumps may suffocate parts of your lawn, mowing over them will turn the leaves into smaller particles which will mitigate oxygen deprivation while increasing moisture retention and nutrient dispersion.
2) Use leaf litter as mulch in the garden
If you decide to leave your leaves where they fall, they will eventually dry up and turn brittle, crunchy and light (perfect for diving into!) Once they've dried up, they can be more easily collected and used in the garden or the compost pile.
To use leaf litter as mulch, you can wait for a hot, sunny fall day and run over the dead leaves on your lawn with the mower, then rake them into a pile near your garden to use as needed. You can also rake them up whole and break them up in your hands as you distribute them across your beds.
Adding mulch over your garden is not only useful during the growing season (to preserve moisture and discourage weeds), but it's just as crucial to overwintering your garden plants. Mulch insulates the plant roots during the cold winter months, and keeps the soil warmer for the bugs and microbes beneath the surface of the soil. And, if your earthworms are happy, your plants are happy!
3) Use leaf litter to prepare garden plots for the following year
We've mentioned it a few times: sodden fallen leaves smother weeds. If you're planning on expanding your garden plot next year, you can make use of the dense coverage to get a head start on prepping your soil for the new addition.
Digging up a garden plot is so much easier without the intrusion of clinging weeds and their roots. Add a thick layer of leaves to the area you're planning on turning into a garden bed to smother the weeds and prevent them from growing back next spring.
In the spring, once you're ready to dig out your bed, you'll have an easier time of it without the new growth. Even better, the previously covered space will now be full of nutrients from the decaying leaf litter; any remaining leaf organic matter can be dug into the soil to improve aeration and continue supplying nutrients throughout the growing season.
decaying leaves in the landfill produce methane, which is terrible for the environment
leaf litter is useful as a garden mulch
leaves can be left in your yard and mowed over to nourish and condition your lawn
leaves can be compacted and used to prepare garden plots for next year's growing season