By James R. Feucht, Colorado State University Cooperative Extension specialist, Landscape Plants
Those golden leaves may be lovely to look at while on the trees, but what are you going to do with them once they're on the ground?
Rather than pack them into plastic bags and haul them away, why not use them to improve your soil? Leaves and garden debris that must be cleaned before winter begins, make valuable compost.
Most Colorado soils are low in organic matter and many are too heavy (too much clay) or too light (too much sand). Organic matter, such as compost, aerates soils and improves drainage. It also increases the water-holding capacity of lighter soils by acting much like a sponge.
Compost adds some minerals to the soil, too, but consider it more a soil amendment than a fertilizer. Most organic materials, such as composted leaves, peat and barnyard manure, are low in nutrients.
You can chose from several methods of building a compost pile, but select a method that matches the equipment available and your experience as a gardener.
Accumulate plant material in a bin or fenced-off area. One of the most convenient structures is a bin made of loosely fitted boards or chicken wire and designed so one side can be removed.
You can start a compost pile any time. Why not begin this fall, when you are cleaning flower beds or raking the yard? If done correctly, the compost will be ready to use by next fall.
Most vegetative matter, such as tree leaves, plant stems, grass clippings and small twigs, makes good compost. Some household garbage, such as vegetable peelings, also can be put into the pile. Don't, however, use animal by-products such as meat scraps and fat. These items are a food source and a breeding site for flies. They also leave the compost pile with a bad odor.
Corn stalks and woody twigs, more than one-fourth inch in diameter, won't break down readily in a compost pile. Their bulk also hinders the process of turning the pile and spreading its contents.
Cottonwood leaves tend to mat and turn rubbery if added to the compost pile in thick layers. Shred semi-dry leaves to eliminate this problem.
The most common method of building the pile is to alternate layers of plant refuse and garden soil. Pile plant materials about six inches deep; add water if it is dry. Sprinkle the plant layer with an inch of soil. The soil provides the microorganisms needed for the decay process. The top layer should be garden soil and should be slightly lower in the center than on the sides; this keeps the water within the pile.
Add a small amount of commercially available nitrogen to the soil, along with about a half cup of ammonium nitrate for each 10 square feet of soil surface.
Shred leaves, plant stems and other debris to speed up decomposition. Use either a home-type shredding machine or a rotary mower.
Use the rotary mower on a level spot that is free of sticks, rocks and other foreign material. Two people can do the job more efficiently than one. One person spreads a thin layer of plant refuse on a level site, while the other moves the mower back and forth over the material.
Never put hands near the mower case. Stay on the side of the mower opposite the grass chute.
The compost will be a dark brown when it is ready for to use. When removing it from the pile, sift it lightly with a spading fork, or shake it through a galvanized wire screen of three quarter inch mesh mounted on a sloping frame. Return material to the compost pile if it is not well decomposed. Spread compost on the garden about two inches deep, and spade into the soil.
For more information about recycling garden debris through composting, contact your local Colorado State University Cooperative Extension office.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010