With leaves starting to fall, can composting be far behind? Composting--as a way to value organic matter for plant and soil health--was recognized long ago by early humans as a good thing. Back then they probably didn't care about leaves dropping on lawns, but outside of every ancient tribal settlement, mounds of fish bones, food scraps and feces accumulated. Some archeologists theorize that our agriculture began with ancient ancestors cultivating the plants that sprouted from village dumps. You've probably discovered something similar in your own backyard, if you have a compost pile. Squashes, tomatoes and all sorts of robust volunteers come creeping out of the pile due to seeds that inadvertently get tossed in.
As agricultural practices were established, the importance of using manures and rotted plants to replenish the nutrients in cultivated soils became an accepted practice. Even as far back as 116 B.C., a Roman named Varro wrote, "There should be two manure pits, or one pit divided into two parts. Into one part should be cast the fresh manure and from the other the rotted manure should be hauled into the field, for manure is not so good when it is fresh as when it is well rotted."
A family of four produces an average of 40 pounds of kitchen scraps and plant debris per week. This debris that we send to the landfill and call "waste" isn't waste at all. Good gardeners and stewards of the land know that you have to train yourself to see the obvious--plant debris is a valuable resource filled with nutrients.
Backyard composting makes common and environmental sense, and it's easy to do. Decomposition is as old as the soil you're standing on. Long before humans were around to observe it, composting was going on in every forest, every meadow, every swamp and every prairie around the world. That's how the living organic portion of soil is made. (The inorganic portion of soil is just pulverized rock.)
Gardeners speed up this natural biochemical process of decay found in nature through composting. Our allies in this rotten venture are billions of aerobic bacteria (those that need oxygen to live), fungi and other tiny critters. Together they're called microscopic organisms or microbes for short. The result of their munching is the dark, earthy-smelling soil conditioner known as humus.
To create your very own precious pile, simply combine equal parts by volume of green and brown materials. Browns are dry, tough, carbon-rich things such as dried leaves, sawdust and straw, while greens are nitrogen rich items like grass clippings, livestock manures and kitchen veggie scraps. Mist the pile lightly with water as you combine the greens and browns, toss in a 2-inch layer of manure or a half-cup of nitrogen fertilizer for every 6 inches of plant material. The pile must be at least 4-foot square to have enough volume to work. To shorten the traditional time it takes nature to make humus (six to nine months), turn the pile regularly, and chop or shred anything added to the pile to create more surface area for the microbes to attack. (By the way, you don't need a shredder to chop leaves, just use your lawn mower or a metal garbage can and a string weeder. Add small amounts of leaves to the can as you shred and wear safety goggles.)
A well-maintained compost pile does not stink. If odors occur, it means that the pile is too wet, or too much fresh, nitrogen-rich stuff was added. Excess wetness or an unbalanced green-to-brown ratio can easily be cured by simply adding more dry brown materials and turning the miracle pile to introduce oxygen.
The payoff at the end of the composting operation is humus, the "black gold" that gardeners crave. Humus will add nutrients and improve the worst of soil structures. Adding humus every year to heavy clay soil will eventually lighten it up, making it easier to work, as drainage and pore space are enhanced. On sandy soils, humus improves the water- and nutrient-holding capacity.
Composting happens whether it's in a fancy compost bin or in an open pile hugging the corner of your backyard. Manufactured composting units have the advantage of being a tidy way to hide plant debris while it composts, and they protect the contents from weather and animals. Models exist that can easily be tucked out of sight in the service area near your garbage cans. With enough bin sizes, styles and price ranges to choose from, making compost becomes as easy as taking out the trash. Just think of your compost unit as another type of recycling bin that easily earns the space it occupies.
To become a composting icon in your neighborhood, join the ranks of the Idaho Master Composters (MC) and walk away with more rotting knowledge than you can possibly share at the dinner table. Applications are now being accepted for this fun course in which tours of composting sites and topics as bizarre as worm wrangling are addressed. MC students are known to get down and dirty with composting cook-offs and insect scavenger hunts. Classes meet once a week for nine weeks. Cost for the course is $50. Contact the University of Idaho Extension office in Ada County for an application at 377-2107.
Suzann Bell is a horticulturist with the University of Idaho Extension in Ada County. Send questions to Suzann, c/o Boise Weekly, or firstname.lastname@example.org.