Composting the autumn leaves that are falling now and using that compost in the garden is a very simple means of returning beneficial micro-organisms, bacteria and fungi to our soils. There’s a long way and a short way to compost – both methods produce sweet-smelling compost than can be used as a soil amendment, a fertilizer or as mulch. Adding compost to garden soils at least twice a year and every time we plant seeds or transplants improves water retention, drainage and soil texture, neutralizes soil pH levels, and also improves plant vigor and disease and pest resistance.
The rapid composting method takes only two to three weeks to reduce small piles of autumn leaves (just leaves and very small twigs with no other additions) to about a gallon bucket of compost per pile.
Start by raking fall leaves into 3-by-3-foot piles. Avoid collecting leaves from trees that have shown disease or insect problems (anthracnose, fireblight, powdery mildew, aphids, etc.). Chop large leaves into smaller pieces to speed up the decomposition process. After making a pile, don’t add any more leaves. Keep the piles evenly moist but not sopping wet. How much and how often to wet the piles depends on how warm the weather is and how much sun the pile gets. Warmer piles decompose faster. Turn the piles every day and in two to three weeks the leaf pile will have turned into a bucket full of compost.
The lengthier composting methods that are used to treat kitchen and garden waste, including fallen leaves, produce even more complex compost loaded with nitrogen and carbon.
The most important step in creating quality compost from a variety of materials is to maintain a consistent ratio of brown/carbon to green/nitrogen. A 30 to 1 ration of brown (C) to green (N) is often recommended, but that can be difficult to figure out. It’s simpler to add equal measures of brown (dry leaves, straw and hay, dry grass clippings, shredded black and white newspaper) and green (unbleached coffee filters and grounds, crushed eggshells, fruit and vegetable peelings, skins and pits, green grass clippings and green yard waste). If the compost pile is not reducing in size and if bits and pieces are not disappearing, it needs more green waste and more water. If the pile has a definite ammonia smell, it has too much green waste and too much water.
The smaller the materials are chopped before putting it into the pile, the faster the process and the finer the compost texture. Pieces that are 1 inch in size or less are ideal. Turn the pile every day or two, keeping it moist but not wet. After the pile has reached the limits of a manageable size, stop adding materials and start another pile. A three-bin composting system or one bin with the use of a compost tumbler will continue the process indefinitely. Depending on weather, it can take from a few weeks to a couple of months in winter for piles to fully decompose.
The heat created by the decomposition process within the pile is not always high enough to kill weed seeds, fungus spores and pest insect eggs. Meat, bones, fats, and carnivorous animal waste should not be added to a compost pile.
Send Elinor Teague plant questions at firstname.lastname@example.org or email@example.com (“plants” in the subject line).