In short, it is not good for leaves to be left to sit after they fall on a lawn… that is, if you would like to continue to have a lawn of grass. If left alone, leaves will mat on top of the grass, cutting out your lawn’s access to sunlight and air, and quickly kill what you once knew to be a lawn. On the other hand, leaves are full of nutrients that are vital for the life of the trees they fell from, and, when they fall, they create habitat and food for all the micro and macro biology that lives on and within the soil those trees (and your lawn) are rooted in.
So, with biology and ecology in mind, if we can’t simply leave the leaves (pun intended 😉), then what are the next most environmentally conscious methods for dealing with them? We recommend composting and/or mulching!
If possible, the leaves that collect on your lawn should be left whole and consolidated into a compost pile, as close to the area they came from as possible (using rakes and tarps are our preferred methods for getting leaves from point A to point B, as it cuts down on fossil fuel use and NOISE!). Composting whole leaves on site means the nutrients stay on site, the habitat value stays on site, your kids, grandkids, and/or pets have a pile of leaves to play in, AND it reduces fossil fuel use compared to transporting the leaves off property. With occasional turning of the pile (and adding of greens) throughout the year, these leaves will slowly turn into beautiful, rich compost which you can then dress back on the lawn, around trees, or in your garden beds.
If you can’t compost the leaves on site, getting them taken to a local composting facility (or a neighboring property/farm!) may be the next best option.
Suppose the distance from your lawn to your local composting facility is 10 miles away… a truck and trailer combo consuming 10mpg is going to take 2 gallons of fuel just to make that trip. In this scenario, or in the scenario of no such facility existing in your area, it probably makes sense (uses less fuel/has less impact) to mulch your leaves instead.
Mulcher/recycling attachments for mowers are relatively cheap, and easy to put on, and simply keep the leaves you are mowing over cycling in the mower deck longer, chopping them up into finer pieces than it would if allowed to side discharge. Mulching leaves in place is beneficial in that it keeps the nutrients on site, skips the raking/moving of leaves and finished compost, and provides some* habitat benefits for the biology we mentioned before (*there will certainly be plenty of casualties during the mulching process*).
#3 Mulching/Shredding and Composting!
Composting leaves whole is great for maintaining habitat value, but it will* take significantly longer for the compost process to happen than it would if you shredded the leaves before piling them. Trade-off of habitat loss and more resource use with the return of a quicker composting process… (have more space to work with? Consider keeping them whole; Less space? Consider shredding).
But wait! There’s more…
Hopefully you have lots more questions about the science and processes behind this whole composting of leaves business, and since we are far from the first people to get into the concept, I’m leaving a series of articles below for y’all to do a deep dive into 😊. I know it’s a tad late for all this information to be made useful this year, but hopefully we will all go into next fall with a much better game plan for leaf management!
Articles on benefits and process of composting leaves
Not all leaves are created equal! (Avoid walnut, eucalyptus and horse chestnut trees)
More detailed compost science… especially as it relates to improving turfgrass.
Article from Scientific American for a fun science activity meant to explore the biodiversity of life supported by leaf litter!