November 20, 2011
Composting is the controlled decomposition of organic material (or plant matter). Decomposition is a natural process in which microorganisms and invertebrates break down materials and return nutrients to the soil. Composting is when we take advantage of this decomposition process and provide ideal conditions in which organic materials can break down as fast as possible.
A significant amount of the waste we produce is food waste. This takes up space and puts unnecessary stress on local landfills because instead of decomposing, the waste rots and releases methane gas that is harmful for the earth’s atmosphere. It is important to compost in order to relieve the pressure on landfills and reduce the amount of waste we produce. Food and yard waste also contain valuable nutrients that we can utilize and return to the soil.
Compost is an excellent addition to any garden. It not only adds nutrients to the soil, but it improves the soil’s ability to hold water. This allows nutrients and moisture to be slowly taken in by plants as needed, resulting in healthier plants. Compost can also decrease plants’ susceptibility to disease. Composting can even save you money! You will no longer have to buy additional fertilizer for your garden, and you’ll save on any garbage collection fees you pay for having yard waste picked up.
There are 4 main things that a compost pile needs in order to successfully decompose materials. They are:
The microorganisms that break down materials in the compost pile need oxygen to survive. Oxygen also helps keep away the anaerobic microbes that create odors.
Your compost pile will need to have some moisture, but you don’t want it to be soaking wet. A good way to judge is that it should be damp like a sponge that was just wrung out. Too much water will drown the microorganisms and attract insects.
The hotter your compost pile, the faster the materials will decompose because the microorganisms will reproduce more quickly. Compost piles can reach temperatures up to 160ºF at the core! These high temperatures can also kill weed seeds so that they do not germinate in your garden when you add compost to the soil.
Having a good mix of ingredients is the key to successful composting. You will need a mixture of carbon-rich material (brown stuff) and nitrogen-rich material (green stuff). Add these to your compost pile in equal weights, so if you add a pound of carbon-rich material, you should also add a pound of nitrogen-rich material. Don’t worry about exact measurements – “guestimating” is all you have to do! Below are some examples of materials that make nice additions to any compost pile:
Green Material (nitrogen-rich)
-kitchen scraps (fruit, vegetables,
coffee grounds, tea bags)
-weeds (without seed heads)
-leftover food from the garden
Note: Too much green material will make
your compost pile begin to smell badly.
This is easy to fix by simply adding more
Brown Material (carbon-rich)
-brown, dried leaves
-sawdust (in moderation)
Note: If you have too much brown material,
the decomposition process will be very slow.
If you notice your pile has a slow decomposition
rate, try adding more green material.
In Minnesota, it’s best to begin composting in the spring once the ground has thawed. This ensures that you can take advantage of the hot summer weather and produce compost for as much time as possible before the ground freezes again in the winter.
Yes! The decomposition process will stop when the ground freezes, but continue to add materials to the pile throughout the winter and everything will start back up come spring. You might consider keeping a bigger container in your kitchen for food waste to minimize trips outside to your compost pile in the harsh winter weather.
Supplies you’ll need:
-box/bin or designated open space
Here are some things to consider when choosing a location for composting:
- If possible, choose a place that is away from trees and vines, as their roots may sneak into your compost pile and suck away nutrients.
- Avoid putting the pile against a wooden deck or fence because the wood may stain and rot.
- An elevated place will help with drainage.
- Partial sun is best. Too much sun will dry out the pile, but you can always add water to help it retain moisture. Full shade means the decomposition process will be slower, though composting is definitely still possible in the shade.
When you’ve chosen your location, clear off a patch of ground and be sure to remove any weeds. This is where your pile will be, and you don’t want to promote weed growth. Using a container for your compost can keep things a little tidier in your yard, but isn’t necessary. If you choose to use a container, find one that has good drainage (you could even put holes in the bottom yourself), and is easy for you to add materials to and mix up with a pitchfork. Many hardware/garden stores carry compost bins. Here are some examples of compost bins:
wooden, can be homemade
wire, can be homemade
open pile, no container
When you add materials, it’s important to maintain a balance of both carbon-rich and nitrogen-rich materials. Rip things up into tiny pieces – the more surface area the material has, the faster it will decompose. Have a container, such as an ice cream bucket, designated for food waste and keep it in the kitchen. Then you’ll have a convenient way to bring your ingredients to your compost pile. See above for a list of green and brown material to add, and below you’ll find a list of ingredients you should not use.
Ingredients that DON’T belong:
-cat and dog droppings (they may carry disease)
-shredded newspaper or office paper (recycle this instead)
-meat, fish, animal fats (will attract unwanted visitors)
-weeds with seed heads
-diseased plants (to keep your garden soil disease-free)
-BBQ grill ashes
Oxygen is another component that is important to the decomposition process. It is important to turn your compost heap in order for air to circulate through it. You turn your compost pile by simply using a pitchfork and moving things around. The tines on the pitchfork will easily penetrate the plant matter and increase air circulation. You may turn your compost as often as you like, and the more frequently you do it, the better. Remember that the core of the heap is where the most activity is, so it’s important for the materials on the outside to make it to the middle. Be sure to monitor the moisture so your pile doesn’t get too dry.
Now you have to let nature run its course. Occasionally turn your compost and add ingredients as they become available, and ultimately you’ll have your own compost that you can add to your garden. You’ll know that it’s done when it has a soil-like consistency and an earthy smell. If you smell ammonia or decay it means the microorganisms are still working and your compost isn’t ready yet. See below for resources with information about finished compost and how to add it to your garden.
The length of time it takes before you can use your compost depends on a variety of factors, including the size of your pile and the surface area of the materials. Smaller piles actually take longer to decompose because their core temperatures do not reach as high as the core temperatures in larger piles. Also, the smaller the materials are, the faster they will decompose because the microorganisms have more surface area to live on. You can expect to have useable compost anywhere from 2-6 months. Once your first pile is established, it will likely move along faster the following season.
It’s fun just to dive right in and experiment with what methods work best for you. Everyone does it a little differently, and you can be as involved with the process as you want. If you’re hoping to create healthier soil in a garden, you’ll probably monitor your compost more carefully than someone simply wishing to send less food waste to a landfill. It all depends on your goals and needs, so have fun!
Check out these helpful resources all about composting:
How to Compost
The Garden of Oz
Step by Step Composting Guide
Adding Compost to Gardens