Learn about Cold and Hot Composting
Composting is the breaking down of organic substances such as grass, manure, and leaves into humus. Humus is a dark organic matter that forms on top of soil as material naturally decays. It is rich in nutrients and is highly desired by gardeners.
Composting comes in two varieties: cold composting and hot composting. Most people are familiar with cold composting, but not as many know about hot composting. This article will discuss how to do both kinds of composting as well as mention the benefits of each.
This type of composting takes longer to reach the humus stage (six to nine months) but is less trouble to do. First, you need to find a place to locate your composting material while the composting is taking place. This compost heap will be there for months, so you need it someplace where you don’t mind it sitting for a long time. Building a simple fence around the compost pile can keep it compact and working well. The fence can be from pallets or wire. It just needs to be about four feet tall and large enough to hold your composting material.
To start your compost pile, layer some small branches on the bottom of the pile. These will not compost well but will increase air flow in the compost pile. After that, you simply layer in alternating layers of brown and green material. Brown material is composed of such things as shredded leaves, wood chips, and shredded newspaper. This adds carbon to the compost pile. Green material is composed of such things as kitchen waste, animal manures, and grass clippings. This adds nitrogen to the compost pile. Don’t put fat or meat scraps in your compost pile because it attracts rats, raccoons and other animals that want the scraps. Also, do not compost manure from dogs or cats or humans because they may contain pathogens that could contaminate the food you fertilize with this material. It is a good idea to add some brown material every time you add green material so they stay in balance.
A good recipe for compost is to put down three inches of brown material, then one inch of green material, then an inch of garden soil. Repeat this until you have a pile about three feet tall. After you finish layering your compost, you need to dampen it to start the composting quickly. The pile should be moist but not soggy. You should periodically water the compost pile so it never dries out.
Once your pile is established, you will need to turn it every two weeks or so. This means mixing the material up and aerating the contents of the pile. This helps the compost process work faster. Your compost is ready to use when it smells like good soil. Everything should be broken down enough that you have no big chunks of material in it. You should not be able to see individual components of the compost such as leaves and grass. It should all be reduced to the rich humus that is ready to put on your garden.
This type of composting is a little more work. Hot composting typically reaches temperatures of 120 to 170 degrees within the first five days, and typically levels out at 150 degrees F. This does not destroy the good micro organisms in the soil, but does kill pathogens and weed seeds.
You will need an equal portion of green material and brown material. The material should be shredded into small pieces before use. Fresh grass clippings and shredded leaves are good materials to start with. Mix them well together and put them in your compost pile. Add a shovel full of finished compost or dirt to add the micro organisms that help with the composting process. The final pile must be at least three cubic feet and no more than five cubic feet to maintain the heat reaction. Water the pile as you build it so that the entire pile is moist but not soggy.
It is a good idea to cover the pile with burlap to hold in moisture and heat. However, not covering the pile will work, too, just a little slower. You will need a compost thermometer to check the temperatures in your pile. The temperature should be checked every day. It should be between 120 and 170 degrees within five days.
When the pile cools to 110 F, every four to seven days, you will need to turn the compost pile. Turn it so that materials that had been on the outside edges of the pile are now on the inside. This should heat the pile back up.
Water it lightly to keep the pile moist but not soggy. Be careful to just moisten the pile as too much water will cool it off.
After fourteen days, the items in the compost will no longer be recognizable. Turn every four to five days to maintain the temperature. It should be turned at least four times in one month.
After one month, the pile no longer heats up after the pile is turned. At this point, the bulk of the compost is dark, crumbly material that smells like good dirt. Let the compost “cure” for two weeks before putting it on your plants.
Advantages of Cold versus Hot Composting
Cold composting is less labor intensive. Once the pile is made, you turn it every two weeks and let it compost. With hot composting, you have a labor intensive process. However, the heat in the compost pile sterilizes weed seeds so they don’t pop up in your garden when you spread the compost out. It also gets hot enough to kill most pathogens, so if you compost a sick plant (which you should not do) the disease is probably killed during the composting. Hot composting yields ready to use compost in six weeks as opposed to the six months cold composting takes (at a minimum).
If you have the time to put into it, hot composting produces better compost and spreads fewer weed seeds or pathogens in your garden. However, making cold compost still puts you miles ahead of gardeners that do not compost at all.