Taken from the Eclectic Gardener @ http://www.teachinggarden.org/
Written by Alan Hickman

In my garden, the first killing frost should have been a couple of weeks ago, but the dahlias and the cannas are still standing tall in the border and, in the shade garden, the begonias are sporting the largest camellia-like blooms I can remember. Just outside my study window, an aster seems to have been in bloom for months, producing wave after wave of large lilac flowers.
After weeks of glorious Indian summer, the recent rains have finally ushered in a very late onset of fall in the city. The leaves on my fifty-year-old maple are just starting to develop scarlet tips and the first few bags of shredded leaves - sucked up from a couple of condominium complexes - have been dropped in my driveway by an eco-friendly landscaper. Even the squirrels seem to have taken notice of the change and have developed a sense of agitated urgency as they scrabble about in the leaf-mulch - planting conkers and peanuts in the newly-moist flower beds.
While most people with gardens are tossing their spades and forks into the back of the garage, the world of plants and trees is preparing for spring. Over the next month or so, in woods and grasslands everywhere, next year's nutrient supply will be laid down. I refer, of course, to all the leaves and dried-up herbaceous growth which will blanket the ground to break down over winter.
Gardeners would do well to observe and to emulate what is going on in uncultivated areas. After all, Mother Nature has been successfully growing plants and trees for a lot longer than humans have! A fundamental principle of nature is that there is no such thing as 'waste'. Everything is used by something and underlying all things is the soil.
Arable soil is made up of four components: air, water, inorganic weathered rock in the form of sand, clay etc., and an organic component - the decayed remains of plants and animals. (Some people add, as a fifth component, all the macro and micro organisms which live in the soil.) It is the organic component of the soil which is replenished and built up each fall.
Each fall, the vegetation in an area lays down a tiny bit more organic material than will be used the following year. And it is just a very tiny bit more. Ten thousand years ago, after the last ice-age and after the water level of Lake Ontario had dropped to reveal the great expanse of clay we call the Peel Plain, there was virtually no organic material in the soil. By the time the settlers came and cleared the forests - a couple of hundred years ago - there were around ten inches of good rich top-soil to support bumper crops of grain. It took ten thousand years to create ten inches of soil. Just a thousandth of an inch of surplus each year!
In a garden, the same mathematics apply. If all the tree leaves and grass clippings and plant stalks are retained and returned to the soil within the garden, there will be a slight but imperceptible increase in the organic content of the soil. As most of us don't have ten thousand years to improve the soil in our gardens, the conclusion is pretty clear. Not only can we not afford to throw away anything which has grown in the garden, if the soil is to be improved, we have to bring in additional organic material and lots of it.
As the organisms which break down raw organic matter into its component parts for soil building are indifferent as to where the material comes from - they'll chew on shredded thousand-dollar bills and frost-bitten marigold stalks with equal relish - the key attributes of organic matter for the garden are that the material be cheap and that it be readily available in large quantity.
While it is lamentable that most people will continue to pull up, rake up, and throw away the resources that nature has provided, there is no reason why the rest of us shouldn't take advantage. A bag of leaves is easily picked up and brought home either to be shredded for winter mulch or to be emptied into a wire cage for storage until next year.
Last fall, in addition to the weekly drop-off of shredded leaves by my tame landscaper, I collected about a hundred bags of leaves from my immediate neighbourhood. A hundred bags sounds like a lot until you realize that what people are throwing out is mostly air. With a bit of stomping, thirty bags of leaves will fit into a wire holding cage four feet in diameter by four feet high.
In a single generation, smoking has become socially unacceptable and obesity is now coming under attack. If we can get to be a nation of healthy-lunged, fit people who don't waste their natural resources, Canada will really be the best place in the world to live.