Q: I’m curious about home compost, both in terms of reducing yard and garden waste sent to landfills, recycling kitchen waste, and improving my garden soil. This year’s gardening season is over, but I’m anxious to do what I can to get ready for next season.
A: El Paso County garden soils vary greatly—some are clayey, others are sandy. All are notoriously lean—low in organic matter. Amending soil with compost is a great way to improve any soil. It attracts beneficial soil organisms and releases nutrients while breaking down. Compost helps the soil hold moisture and makes it available to garden plants.
Commercial compost can be a combination of plant residues, manure, animal by-products and possibly bio-solids, and can be at any stage of decomposition. Colorado does not regulate compost. While these products will provide a long-term release of nutrients, add organic matter, and improve soil properties, they may also increase the salt content of the soil. If the contents have not been thoroughly composted, they can be “hot” with high ammonia levels, which will burn tender plant roots.
Homemade compost offers a great solution by improving the quality of our garden soil while recycling our “green waste.” In addition, composting at home allows the gardener to control the content of the compost, avoiding weed seeds, diseased plants, and salt problems.
Traditional compost consists of layers of different types of shredded plant materials. An equal amount of dry or brown material and green or live material is the goal. Soil is an additional layer in the compost mix, but that can be supplied by the amount of soil that clings to plant roots. When container gardens have finished for the summer, the exhausted potting mix may also be included. Water needs to be added to the compost after every few layers of material. Dry compost will not decompose. Overly wet compost may smell and become slimy.
Temperatures in the home compost can vary, with outer layers being cooler. Stirring the compost enhances the breakdown of materials, which increases the temperature inside the pile. Most plant disease organisms are killed if the compost reaches 122 degrees F, but that’s difficult to achieve in our cold climate. This means that diseased plant tissue should probably be disposed of in the trash.
Most home gardeners compost kitchen wastes such as fruit and vegetable scraps, coffee grounds, and egg shells. These materials compost well, add moisture and are usually not produced in overly large proportions. If there are bears and raccoons in your neighborhood, it is a good idea to stir the compost any time kitchen scraps are added. Avoid animal wastes such as bones, grease, and dairy products that can cause orders and attract animals.
Avoid composting plants that have been treated with weed killers or other pesticides. New strains of E. coli and other bacteria that can cause human illness should be avoided by safe food handling/cleaning procedures. Do not compost any type of animal or human feces.
Good compost will have an earthy smell and be dark and crumbly in appearance with little resemblance to the materials composted. If your compost has not quite finished rotting, adding it to the soil in the fall will allow it to completely break down over the winter.
Perhaps this was the first year you attempted to make home compost, and the results were not exactly stellar. Summertime provided far more “green” materials and food scraps than “brown” materials. Moisture might have been difficult to modulate, and perhaps mixing or stirring didn’t happen often enough. The compost container or pile might not have lent itself to easy access.
Use these winter months to explore composting structure options—pits, wood bins, plastic bins, wire bins are some of the different types available. Plastic compost bins were available at the “big box” stores last spring for less than $50. Collect the leaves you rake up this fall to provide the “brown” materials not available in summer months. Leaf mold is a great compost ingredient and those leaves will be completely broken down by next fall. Is the location of your compost bin convenient? Ideally it should be in a mostly sunny location close to the garden, yet convenient for emptying kitchen scraps. If the system is functioning, you will be able to feel the heat when the pile is stirred.
Creating your own compost is a very simple and satisfying achievement, improving garden soil and keeping green waste out of landfills. Compost, in addition to mulch and fertilizer, can greatly enhance your gardening success.
Contributed by Peg Zimprich, Certified Colorado Gardener. Compost bin photo courtesy of Leslie Holzmann.
Access fact sheets and seasonal information on the El Paso County Horticulture website. For more information on the Colorado Master Gardener program and other garden help, go to the Colorado State University website.