Climate-Wise Landscaping Blog
- Published: 23 April 2013
Keep that yard clean! This social imperative began in the 1800’s, when tidying the yard was considered an essential civic behavior, and continued through the 1900’s, when a vast swath of vibrant green lawn became evidence of one’s high social status. Now in the 21st century, however, perhaps it’s time we give this old social norm some new thought.
One big thing to reconsider is the idea that all the leaves that fall on the ground beneath a mature tree should be raked up and removed. As it turns out, this practice is actually not beneficial to our landscapes, for several reasons.
Nature has developed a perfect system. Plants build themselves out of sunlight, water and soil nutrients. When these plants shed parts of their body, or when they die, the nutrients they once held return to the soil, through gradual decay, for future use. If we rake up and remove fallen leaves, we are robbing the soil of these valuable nutrients.
As Sarah Stein wrote so eloquently in her book, Noah’s Garden: “Recall, before laying down a mulch of pine bark, that each bush or tree is accustomed to a cover of its own dead leaves below it, and so are the decayers that re-feed it.” (page 135).
Without the “food” provided by decayed fallen leaves, trees get neither enough nor the right nutrients they need to thrive. We can try to replace those nutrients with manufactured chemicals and amendments, but getting the perfect blend is nearly impossible. And why do this, when the tree is already giving us what it needs, for free?
Many moth and butterfly species lay their eggs and construct their cocoons on tree leaves. The next generations of countless pollinators lie curled inside countless fallen leaves on the ground, waiting for spring. If we rake up the leaves and pile them in soggy heaps or stuff them into bags destined for the landfill, or if we grind them up and suck them into mower bins, we kill these valuable and beautiful creatures.
Denuded ground below a tree will not automatically grow grass. Lawn grass needs its own unique set of growing conditions, which are often not met under a big shade tree. So simply removing the leaves will likely not get you the results you want. Mosses may try to grow in the resulting bare ground, in nature’s attempt to repair the situation, but continual passes with a mower will likely prevent a successful moss carpet. The outcome may be a bunch of unwanted weeds, or lifeless ground.
Removing fallen leaves uses energy. Ideally, this energy comes from our own human effort, but far more often it comes from gasoline-powered equipment, which is a waste of precious natural resources.
What to Do Instead
If you have one or several large trees in your property, you could create a large area around their trunks where fallen leaves are allowed to remain in place, right where they fall. This might involve widening an existing mulch circle, or creating an entirely new one, really big, at least all the way out to the tips of the branches.
You could plant in this mulched area drifts of ferns, spreading perennials or shrubs (native plants, please!). Alternatively, if you prefer the open look and you live in an area where people are concerned about leaves blowing around, you could lay deer netting over the carpet of leaves, pin it in place with twigs, and leave it there for the winter. By winter’s end, the leaves will be matted down enough to not get picked up by the wind, and in spring you can remove the netting.
Best would be for all of us to relax a little bit about leaves blowing around during winter, and instead wait until spring to tidy up where necessary. Here’s one interesting article that explores more about this approach. And here's another one.
I’m not suggesting that we shouldn’t rake leaves ANYwhere, just that we should think twice about raking leaves EVERYwhere. Of course it may make sense to rake leaves off important areas of lawn. If so, we can use these leaves as mulch elsewhere in our landscape, or add them to a compost pile. Or in some situations it could work to grind up the leaves really small (with a mower) and let them decompose where they lie on the grass.
The main goal here is to make the most of fallen leaves, which are nature’s free resource for nourishing the soil and the beings that live on it and in it. And, if possible at the same time, to reduce our consumption of carbon-based fuels.
We don’t need to keep doing things the way they’ve always been done, especially if these old ways don’t represent our current knowledge and values. Raking less or not at all? Good idea.
“The fusion of practicality, comfort, pleasure and ecological soundness is a hallmark of Sue Reed’s design work. Her extraordinary abilities to thoroughly diagnose situations, develop appropriate solutions to shortcomings, and clearly explain process and detail have been repeatedly demonstrated during her years of private practice and teaching at the Conway School of Landscape Design.”