August 20, 2006

This is the time of year when leaves begin to fall–hence the season is called fall–making lawns rather unsightly. Our flower beds are beginning to fade because of environmental adversities. Whatever the case, we need to gather the leaves and discard plant rubbish.

Is this debris trash or treasure? It can be treasure if you don’t dispose, but rather compost! A ton of leaves is worth over $10 in nutrients alone. Leaf mold has a miraculous ability to hold moisture. Subsoil can hold a mere 20 percent of it’s weight, good topsoil will hold 60 percent, but leaf mold can retain 300 to 500 percent of its weight in water. Leaves and plant material can be used to improve growing conditions for the next season. Composting is the “natural” way of doing things. Nature has been successfully composting for millions of years.

Compost is a mixture of decomposing and rotting debris that can be used to add fertilizing elements back into the soil. The compost process returns plant and animal matter back to the soil and completes the natural life cycle. This cycle began when you planted the seed. As the small plant grew from the seed, it took nutrients from the soil to make cells and metabolites. As the plant grew larger, more minerals were required and accumulated. When the plant dies, it decomposes and the “borrowed elements” are returned to the soil. Thus, the cycle is completed. At this time of the year, you decide whether this natural recycling system will benefit your soil or the garbage dump.

If a compost pile is properly made and maintained, an excellent composted material should be ready for use in 90 to 120 days. I recommend the “sandwich” composting method. This involves piling layer upon layer of compost material to create a “sandwich” effect.

Three methods of composting:

The advantage of using organically-released fertilizer elements is mainly one of economics. They are free!!! Gardeners should realize that organically released fertilizer elements do not differ in any form or fashion from those fertilizer elements obtainable from other sources. The organic combinations of elements must be reduced to some soluble inorganic form before being absorbed by plants again. These inorganic forms are also found in commercial fertilizers. Armed with this information, one can readily recognize the fallacy in the claim that vegetables and other food products that have been fertilized with chemical fertilizers are somehow harmful to human health. Some claim they are not as tasty as those in which the same elements were supplied from compost or other “natural fertilizers.” The main advantage, other than an economical fertilization technique, is that compost added to the soil will improve soil tilth and its ability to hold moisture. These factors will encourage optimum plant growth and maximum yields if proper cultural practices are followed.

Basic items that can be used for composting include:

GRASS CLIPPINGS: Mix green, fresh clippings with soil or dry plant material such as leaves. Be sure that large sprigs that could root and propagate themselves are eliminated. A thick layer of fresh clippings usually compacts when it settles. This prevents air from entering the pile and slows or prevents the composting process. To prevent this problem, add and dry thin (no more than 3 inches deep) layers of green grass clippings. Also, denser organic materials can be intermixed with grass clippings to prevent compaction. Grass clippings are relatively high in nitrogen and make good compost.

DRY LEAVES: These are plentiful in the fall and often can be found in bags by the curb waiting for the garbage collector. Most leaves compost faster and more thoroughly if shredded before adding to the pile. If you do not have a shredder, place the leaves in a row on your yard and cut them up with a rotary lawn mower. Rake the chopped leaves and add them to the compost pile. Shredding greatly increases the total surface area of a material. The conversion of raw organic material into colloidal humus is accomplished by a series of fermentations. These fermentations consume the plant residues like a living fire. The finer the particles, the faster they will be consumed. The faster a compost is made the better it is because there is less time for the dissipation of valuable gases and the leaching out of essential elements.

KITCHEN SCRAPS: Fruit and vegetable trimming and leftovers are good items for the compost pile. DO NOT use animal products such as grease, fat and meat trimmings since they break down very slowly, attract rodents and other pests and have an unpleasant odor. No one appreciates a rat sanctuary or a buzzard roost in a neighbor’s compost area! Offensive odors will also develop if the compost piles become soggy or anaerobic (lack of sufficient oxygen).

Remember to turn and moisten the pile every 2 to 3 weeks to provide proper aeration and temperature. However, do not keep the composting material too wet. Offensive odors will develop if the compost pile becomes soggy or anaerobic (lack of sufficient oxygen). For this reason, piles should be kept moist and open by periodic spading. This will not only reduce odor, but will also hasten the decaying process. When the pile begins to “work,” it will have a hot (160 degrees F.) internal temperature. It is absolutely essential that the compost pile be well ventilated so that there is a sufficient flow of gases between the atmosphere and the interior of the compost pile. The soil organisms that break down the plant residues and convert them into compost are aerobes, i.e., they must have oxygen to live. The composting process will stop if these organisms suffocate and die because lack of oxygen.

The whole point of composting is to produce a beneficial soil additive. Moreover, humus is recognized as an excellent soil conditioner. Besides increasing the soil’s water holding capacity, improving its tilth and aeration, compost also makes plant nutrients already in the soil more available to plants. However, compost is rarely a complete fertilizer. Depending on the starting materials and the length of time it is allowed to stand before it is applied to the soil, compost may or may not be a good source of the trace elements necessary for plant growth. The same is true for the macro nutrients, which are leached from compost if it is allowed to stand unsheltered in the rain.

So, do not be wasteful, and let’s make and use compost. Compost is a wonderful soil amendment for the vegetable garden or landscape, improving soil structure and texture while adding valuable plant nutrients. It can also be used as an amendment in potting soils or as a top-dressing on lawn and ornamental areas. Let’s start composting today! For more information, check out “Don’t Bag It Leaf Management/Compost,” an online article published at http://aggie-horticulture.tamu.edu/earthknd/compost/compost.html

Remember, Learn and Have Fun!

David Rodriguez is the County Extension Agent-Horticulture for Bexar County. He represents Texas Cooperative Extension with the Texas A&M University System. For any landscape or gardening information, call the Bexar County Master Gardeners Hotline at (210) 467-6575, email questions to mg-bexar@tamu.edu, or visit our County Extension website at http:bexar-tx.tamu.edu

Special Note: Listen “live” with David Rodriguez every Saturday morning between 8:00- 11:00 am on WOAI 1200 AM Gardening Show. Feel free to call in at 737-1200 or 1-800-383-9624. Check it out!