Compost is decomposed organic material that is made up of material such as leaves, shredded twigs, and kitchen scraps from plants. When you add compost to clay soils, it is easier to work and plant. When you add it to sandy soils, the compost improves the water holding capacity of the soil. Adding organic matter to the soil can help improve plant growth and health!
Why does it matter?
First and foremost, plants get their food, also known as nutrients, from the soil. Nutrients are very small, basic elements found in soil. For example, if we grow onions and lettuce in a garden bed, the roots of the lettuce and onion plants “eat” the nutrients in the soil. If the lettuce and onions get enough nutrients, they will grow big enough for us to harvest and eat them.
What happens to the soil’s nutrient supply if we keep planting lettuce and onions? The soil runs out of nutrients. Therefore, there must be a way to replace these nutrients. Composting solves this problem.
Second, it can help us save space! Given the amount of organic garbage Austin produces, imagine the space we could all save if we composted all of our kitchen scraps. Food waste that has been littered or put in a landfill takes many months to decompose (if ever). In a compost pile, the same item can decompose in just a few days!
In addition to saving landfill space, composting can help us decrease our dependence on harmful chemical fertilizers.
What is compost made of?
The composting process involves four main components: organic matter, moisture, oxygen, and decomposers. Bacteria and other microbes are the real workers in this process. When we supply organic materials, water, and oxygen, the already present bacteria will break down the plant material into useful compost for the garden.
- Decomposers – these are the organisms (bacteria, fungi, and invertebrates) that eat the organic material
- Carbon Sources – materials rich in carbon such as dead leaves, wood chips, and paper
- Nitrogen Sources – grass clippings and most food waste
- Air – too little oxygen causes foul smelling anaerobic bacteria to take over a pile; air can be worked into a compost pile by turning regularly
Water – compost needs water to create the perfect habitat for decomposers. A compost pile should be damp like a wrung-out sponge.
What can I compost?
Composting is a lot like baking a cake – ingredients are added, time is allowed for baking, a chemical change takes place, and the final product is compost. Many people think soil must be added to the pile, but in fact soil is the end result!
Different types of compost need different things. Your backyard compost can handle a lot of organic material, but does not get hot enough to break down things like meat or dairy products. However, commercial composts do! If you have your green commercial composting can from the City of Austin, you can add a wide variety of kitchen scraps that will breakdown just fine in the massive piles at the commercial composting facilities.
| All Compost Types | Commercial Compost Only |
| Vegetable and fruit scraps | Meat and grease |
| Eggshells | Oil and sugar foods |
| Coffee grounds and tea bags | Sauces (spaghetti sauce) |
| Nut shells | Bones |
| Dryer lint and dog hair | Dairy (milk, cheese) |
| Paper | Cardboard |
| Herbivore pet waste (rabbits, chickens) |
How can I get started?
First, determine what type of composting you will be doing. If you don’t have a collection bin, you can reach out to the City of Austin to check if this service is available for you and request a bin. Want to make your own composting system at home? The city has a home composting rebate program for that as well!
Next, set aside a container in your home for collecting compost materials and put it somewhere easy for you to access. When you’re ready, take the scraps outside to your compost bin, whether that be your backyard or your city bin. TIP: if you are collecting for commercial composting and you don’t want those scraps getting too stinky, store your smellier collected compost in the freezer until pickup day.
Are you an educator who wants to teach your students about composting? Check out our education programs to learn more.
