Fallen Leaves

Most years, we don't get snow before January, so we have lots of time to get the leaves raked, should we choose to do so. Today I started raking up some of the big leaf maple (Acer macrophyllum) leaves that currently carpet sections of the yard.

 

I do actually rake the leaves.  I am morally opposed to gas-powered leaf blowers. Why would I spend money on a machine and gas to do a job that I can do as easily by myself? Why would I forgo exercise and fresh air in exchange for exhaust fumes and contributing to climate change?

 

There is actually an argument for NOT removing leaves from your lawn. The recommendation is actually to spread out the leaves in an even layer over the lawn and then mow the leaves and allow the minute pieces of leaf to remain on the lawn to decompose and add their nutrients to the soil. For me this isn't practical. All my big leaf maples are in the wooded parts of the property and the only leaves I bother to rake are those that fall from the edges onto the lawn. It's easier to rake them up and put them in my long-term compost than try to spread them so they carpet a wider area.

[I’ll mention here that I employ 3 methods of composting. Firstly, kitchen scraps, eggshells, lint from the dryer and shredded paper go into a worm bin (see adventuresinvermicomposting.blogspot.com). Secondly, large volumes of kitchen waste, pet litter and compostable paper products all go into a large covered compost bin which I turn with a pitchfork whenever I remember, or otherwise just leave. Thirdly, I choose a spot in the woods each year to put yard waste and long-term compost. I leave it for 3 or 4 years and it breaks down on its own over time.]

The other reason to not rake leaves is that it provides habitat for insects and small amphibians.  A search on Google for “leaf litter life” reveals a plethora of videos and articles showing and describing the various insects, arachnids, gastropods, amphibians, and mammals that live and die among fallen leaves.  When I address the leaves on my lawn, I don’t do all of the raking in one day – not only would that completely wreck my back, but I feel it gives time for the animals to migrate if they need to rather than disrupting everyone all at once.  I love to see the birds rifling through the leaves and even tossing them in the air in pursuit of the creepy crawlies underneath.

One thing I have noticed about the fallen maple leaves in our yard is that they have clusters of little raised black dots around the edges and the leaf veins. 

 

With a little research, I have determined that these are a fungus called Rhytisma punctatum. This doesn’t appear to be harmful to the tree nor does it cause a problem with aesthetics while the tree is in leaf – the fungus makes its appearance as the tree is preparing to drop the leaves anyway.  If I wanted to get rid of the fungus, I would have quite a job of it since I would need to gather up ALL the leaves and burn or otherwise remove them from the vicinity of the trees before spring when the new leaves emerge.  Since that won’t be possible, we are embracing the fungus as part of the biodiversity of the yard.  (See Tom Volk of the University of Wisconsin’s Fungus of the Month blog for a discussion of Rhytisma.)

 

 

 

 

 

 

 

See also an interesting project involving a women’s corrections facility and Evergreen State college helping to study the the fungus in the Pacific Northwest:



http://blogs.evergreen.edu/sustainableprisons/blog/2012/12/12/butterfly-techs-at-mission-creek-helping-with-the-evergreen-environmental-observation-network/