One of the most important parts of gardening is ensuring that what you have planted is getting the nutrients it needs to produce properly. Most soil is not naturally rich with all the things that plants need to thrive, so one way to give your plants what they’re craving is by incorporating compost into your garden.
Composting requires four basic properties: air, water, carbon and nitrogen. Air to feed the microorganisms that break down the ingredients of your compost pile, water to encourage decomposition, carbon as an energy source for the microbes that are breaking everything down, and nitrogen as protein for the microbes. There is also a very specific ratio between the amount of carbon (brown matter) to the amount of nitrogen (green matter) required. Generally one part green to two parts brown is an appropriate ratio.
There are two methods for creating compost: cold compost, which requires very minimal effort but takes a long time, and hot compost, which requires quite a bit more effort but gets you your compost in a very short amount of time.
Cold composting very basically consists of creating a pile of yard waste and waiting from anywhere between 6 to 24 months for microorganisms, earthworms and other insects to break the pile down for you. You can expedite the process by occasionally checking moisture levels and “turning” the pile. Generally the compost at the very bottom of the pile will be ready for use first, so long as you avoid adding wood material to your pile, as it takes too long to break down. You can continually add material to the top of the pile. A downfall to this method, however, is the fact that the pile does not heat up enough to kill pathogens and weed seeds, so you are taking a risk with that.
Hot composting consists of amassing a large amount of both green and brown matter and layering them in a large pile. You need to have enough material collected to create an appropriately sized pile that will be able to hold heat and assist effectively in decomposition. “Brown matter” is considered carbon rich material such as dried leaves, straw and cornstalks, and “green matter” is considered nitrogen rich material such as grass clippings, plant clippings, fruit and vegetable scraps, tea leaves or bags and coffee grounds. You will need one part green matter to two parts brown matter in order to create the optimum environment for decomposition. Moisture level is just as important as the ingredients you use, as the moisture encourages decomposition. If any of the layers of ingredients that you are adding to your pile are dry, be sure to moisten them with a hose before adding more material. Along with maintaining moisture level, you will also need to fluff or “turn” the pile weekly throughout the season with a pitchfork, as well as continue adding layers. Make sure your pile is 3′ x 3′ x 3′ minimum, and the microorganisms will immediately start decomposing, their bodies releasing heat. The pile will insulate the heat, and the temperature of the pile’s interior will reach 120°F to 150°F. After the first month, the temperature will start to decrease, and once the pile is no longer hot, the ingredients all unrecognizable, your compost will be ready to use. Though this method does take much more work, you will have useable compost within 2 months, and sometimes even within weeks. It also gets hot enough to kill pathogens and weed seeds, so your compost will be as pure as possible.
Here is a diagram of how you can layer your compost. Be sure to leave the compost layers in place for at least a week so the pile can get up to temperature, and then begin your turning regimen.
There are a couple ways that you can “turn” your pile, which is basically agitating the pile of compost so that air will get to the microorganisms that are breaking down the pile. The most commonly instructed way to do this is to physically turn the pile by hand with a pitchfork so that the material on the outside of the pile is brought into the center of the pile. Another way that a lot of backyard gardeners use is actually impaling the pile to aerate it, using a garden fork or a pipe. Others use the actual structure of the pile itself by layering coarse material like sticks, hay, etc., so the aeration is already built into the pile and no additional aeration is needed. Large compost piles should be turned for the first time after two weeks, as that will give the pile adequate time to heat up and start breaking material down. Turning the pile additionally every week is suggested for appropriate aeration. If you are maintaing your pile during the winter, it is suggested that you stop turning the pile after November, so that the least amount of heat escapes as possible during the cold winter months.
There are several commercial compost starters that will assist you in getting your pile going if you do not have the correct ratio of brown matter to green matter on hand.
In regards to layering, there is a basic set of guidelines that you can follow. Be sure to start your compost pile on bare ground, as contact with the ground will provide the bacteria needed for the composting process. A common structure that is built and used by backyard gardeners is a wood frame with wire fencing caging the compost in. The first layer you’ll need to place at the bottom of your bin is a 6-8 inch layer of coarse material, such as cornstalks, small twigs or chopped brush. This will promote air flow and proper drainage. Layer on top of that a few inches of green material, such as grass clippings, fruit and vegetable scraps, tea leaves or bags, and coffee grounds. Then add twice as much of a layer of fallen leaves, pine needles, cornstalks, wood ashes, paper egg cartons, twigs and branches, sawdust, wood chips or shavings or finely shredded newsprint. Always be sure to cover exposed food matter with a layer of dried leaves or grass clippings to deter any pests that would be attracted by the odor. As the compost cooks and reduces, be sure to keep the pile moist at all times and continue to add layers if you have the material. The more material you add, the quicker the bacteria will reduce it to compost, but be sure that all material is either shredded or ripped into small pieces. Material that is in too large of a chunk will not decompose properly. Be careful not to over or under water the pile, however; too much water will cool the pile off too much for the bacteria to want to work, and too little water can cause the pile to dry out so the decomposition is unable to happen. Here are some common issues and how to solve them:
Problem: The compost has a bad odor
Solution: The pile is not getting enough airflow, so turn it. It also may contain too much water, which can be resolved by adding a porous material such as sawdust.
Problem: The center of the compost pile is too dry
Solution: The pile is not getting enough water. Moisten and turn the pile until it reaches the moisture level of a wrung out sponge.
Problem: The compost is damp and warm in the middle, but nowhere else
Solution: The pile is too small with not enough material to create the decomposition that is required. Add more material to the pile and mix it in with the old material.
Problem: The heap is damp and sweet-smelling but still will not heat up
Solution: The pile is not getting enough nitrogen, or green matter. Try mixing in some grass clippings or manure into your existing material.
While most organic matter can be composted, there are a few things that should never be added to your compost pile:
- Diseased plants or leaves
- Persistent weeds (poison ivy, multiflora rose, bindweed, quackgrass, etc.)
- Human or pet feces
- Meat, dairy products and kitchen vegetables cooked with animal fats
- Plants that have gone to seed
These items can contain pathogens and will attract pests, so it is best to keep them out of your pile. Some weeds are alright to add to your pile, so long as it is large enough to produce an amount of heat hot enough to kill any weed seeds that are added.
Your compost is ready to be used when it looks dark and crumbly and none of the starting ingredients are visible. The compost should smell earthy and should be fluffy, not crumbly. One way to test if your compost is finished is to seal a small sample in a plastic bag for 24 to 48 hours. If you do not smell any strong odors when you open the bag, the compost is done.
Be sure to save all your kitchen scraps in a bin or bowl so that they can be added to your pile. Things like fruit and vegetable scraps, eggshells, coffee grounds and tea bags or tea leaves are great things to compost.