Compost: Black Gold for Gardening
Question of the month for August 2021: My family is thinking about using compost more and using store-bought fertilizers and soil amendments less. Can you tell me more about compost and how to make it?
Compost or “black gold” as gardeners like to call it, is the product of nature's process of decomposition in the soil. Nature takes once living organisms such as leaves, grass, and most any plant-based material and breaks them down into a crumbly, dark-brown, soil like organic material. Nature uses actinomycetes, bacteria, fungi, and many other organisms such as ants, worms, and pill bugs to do the work. Decomposed properly, compost will provide a constant source of slow release nutrients for your landscape and vegetables. There are many benefits to compost.
- Because the living material decomposing already contains most if not all of the nutrients needed for plants to grow, using compost reduces the need for using fertilizers or soil builders.
- Compost increases the soils capacity to retain both moisture and nutrients.
- Compost releases nutrients slowly because the decomposition process is slow.
- Compost loosens up the soil improving the soils ability to create space for oxygen and drainage.
- Compost, an organic material, benefits the microbial life in the soil. The more microbial life in the soil, the healthier the soil.
Choose a site. Your compost site should be in a sunny/part shady location with good drainage. The compost pile can just be a pile on the ground, the pile can be enclosed in a bin or you can buy a tumbler at the local big box home improvement store or nursery.
Start the compost pile. The compost pile should contain 75% brown material, 25% green material, and water should be added to moisten the material. In the beginning you should add some soil or aged compost to introduce microbes to the pile. Brown material is basically a source of carbon. Examples are wood branches, dried leaves, shredded paper, straw, paper towels, twigs and wood chips. Chop up this material as finely as practical before putting it in the pile. This helps the microrganisms decompose the matter quicker. Green material is basically a source of nitrogen. Examples are bread, coffee grounds, eggshells, grains, grass clippings, hay, pasta, tea bags, and vegetable and fruit scraps.
DO NOT ADD THESE ITEMS to the compost pile:
- Bones, dairy products, grease or meat.
- Cat or dog manure.
- Charcoal ashes or treated wood which may contain toxic compounds.
- Herbicide or pesticide treated plants.
- Sick or diseased plants.
These materials can create foul odors, attract rodents and other pests, and contaminate your compost pile. Keep your compost pile chemical free!
When starting the pile, think layers. Start with a layer of brown material. Next, a layer of green material, a shovel full of existing soil or compost and moisten the pile with water. You can add layers in this order once or do it multiple times. At this point your pile has been started. From this point forward you will need to maintain your pile. There are two ways of maintaining your pile: either aerobically (active and with oxygen) or anaerobically (passive and without oxygen).
Composting aerobically will create compost faster but requires a strong back and a shovel. After the first week turn the pile over. Then turn the pile over once a month. Each time you turn the pile, add water to keep the material moist, not wet. Your pile should heat up in about five days to around 90-140 degrees. If everything is decomposing properly, you will see your pile get smaller as the material breaks down. Using the aerobic method, you should have compost in 3-4 months. Composting anaerobically will create compost more slowly. Using this method, once you start the pile you just leave it alone. Do nothing! It will take 6-12 months to create compost this way.
If your pile is not progressing the way it should you have a problem. There are many causes for this but the most common problem is either adding to much water to the pile or not adding enough. Remember to keep the pile moist, not wet. The pile should have the consistency of a wrung out sponge. Finished compost will be a dark, crumbily soil mix with small pieces of organic material, and a sweet earthy smell. For more information on composting Texas A&M Agrilife Extension Service has a good article on the subject. You can find the artilce at https://agrilifeextension.tamu.edu/library/gardening/composting/.
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