What Should You Put in a Compost Bin?

May 5, 2023

You’re all set up with your compost bin and ready to start making compost. But wait—what exactly are you supposed to put in it? Truth be told, some items are more appropriate for a compost pile than others. Let’s avoid the confusion and jump into the best materials for composting.

You’ll have a nitrogen- and carbon-rich material for your garden in no time.

Why Start Composting at Home?

Finished compost is recycled food scraps and other organic materials that’ve been broken down by decomposers and contain multiple nutrients that benefit soil. As a result, the benefits of composting are both personal and environmental.

Environmental benefits

Compost is a natural and chemical-free alternative to fertilizers and pesticides. Commercial fertilizers make soil dependent on chemicals instead of cultivating natural, rich nutrients from organic matter, ultimately resulting in unhealthy soil and poor crop yields. These chemicals then leach into aquatic environments, causing algal blooms that starve aquatic creatures of oxygen.

Soil treated with compost also retains more moisture, so crop fields and gardens need much less irrigation. Soil with an extra 1% of organic matter needs 20,000 fewer gallons of water per acre.

Last but not least, composting reduces the effects of climate change. Food waste in landfills breaks down in a process called anaerobic composting, releasing biogas—a mix of carbon dioxide and methane that fuels climate change. Composting kitchen waste and similar materials reduces greenhouse emissions by as much as 50%.

Personal benefits

As attractive as reduced methane emissions and a smaller carbon footprint are, compost offers multiple personal benefits when mixed into your garden soil, garden beds, and houseplants, nurturing plant and flower growth and making them healthier and more colorful. As it helps soil retain moisture, it cuts down on the amount of watering necessary, saving you on water bills. You can expect the following results from adding compost to your soil:

  • Greener, lusher grass
  • Fewer weeds
  • Longer-blooming flowers
  • Lower maintenance needs

How compost helps soil

The benefits of compost are driven by the nutrients, organic material, and microorganisms it contains. Phosphorus, potassium, and nitrogen are found in abundance, but the exact amount of this depends on the raw materials you put into your compost pile. As a result of natural chemical processes, these nutrients combined with microbes and other organisms mineralize the soil to provide slow-release, long-lasting benefits. Compost contains myriad beneficial nutrients and micronutrients:

  • Manganese
  • Copper
  • Zinc
  • Iron
  • Iodine
  • Magnezium
  • Calcium
  • Carbon
  • Sulfur
  • Boron

These are all found in lower doses than the potassium, phosphorus, and nitrogen that compost includes, though the exact amount depends on the specific mix of green and brown materials in your compost bin. All plants and flowers benefit from these nutrients, and you’ll enjoy everything from greener grass to increased crop yields without the need for chemical fertilizers.

Composting Basics

You should know a bit about composting before you get started. To skip to the section on what you can put in your compost pile, click here.

At its core, composting needs three ingredients, and you’ll need the right blend to make sure it’s as nutrient-rich as possible. The right amount of moisture is important, as you’ll have to ensure the compost is damp without being too wet. Too many wet materials will cause the compost to stink, while too little can make the process take longer.

Green materials are nitrogen-rich materials, a category that includes fruit and vegetable scraps, grass clippings, coffee grounds, and similar waste. Brown materials are carbon-rich materials, dead leaves and similar dried yard waste, cardboard, compostable egg cartons. These dry materials will help keep your compost pile from being too wet.

Aim for 30 parts brown materials for every 1 part of green materials, though this is the most conservative carbon-to-nitrogen ratio. Some experts advise a 20:1 ratio, and others even go as far as to say that a 50:50 ratio is appropriate. Monitor your compost pile for fruit flies and odor, which may indicate a need for more carbon-rich materials. You may find you have more green waste than brown, so achieving that 30:1 ratio can be difficult. Just do your best, keep an eye on it, and you’ll have a healthy compost pile.

Another important element of most composting bins is aeration, or turning your compost pile frequently to add oxygen, encourage decomposition, and keep your pile from decomposing anaerobically.

What Is a Compost Bin?

Compost bins encourage the decomposition process and create an ideal environment to cultivate healthy compost out of your organic waste. A compost bin breaks down yard waste, coffee grounds, fresh grass clippings, tea bags, kitchen scraps, and other organic waste to create fresh compost, which can then be used on soil.

How a compost bin works

Compost bins break down your kitchen and garden waste to decompose faster than they would in nature. Not all compost bins work the same, however. Some use hot composting and others use cold composting. Hot composting is the easiest and most popular because it’s faster and destroys any diseases that may have made their way into the bin.

They’re also split between aerobic decomposition, which occurs in nature and uses oxygen during decomposition, and anaerobic decomposition, which breaks down compost piles without using oxygen. Anaerobic decomposition doesn’t involve aerating your compost pile, so it’s a more hands-off approach to composting. It runs the risk of creating biogas, which undoes the environmental benefits you’re trying to achieve.

Types of Compost Bins

Before you can start composting, you’ll need to get a compost bin. You can choose from several types, each of which operate differently. Here are some of the most common types of composters:

Stationary composters

Stationary composters don’t require much effort, as they’re usually designed to use either aerobic or anaerobic decomposition, so you’ll need to pay attention to this before buying. Aerobic decomposition takes more effort and is better for the environment. Anaerobic, on the other hand, is as simple as adding the food scraps in through the lid at the top. Once the materials are composted, you can remove them from the bottom of the bin.

Compost tumblers

Sometimes called a batch tumbler or tumbling composter, a compost tumbler has several compartments designed to be filled with organic matter one by one, so you can have materials in different stages of the composting process. A compost tumbler also includes a rotating drum to make aerating easier.

Worm composters

As the name suggests, these use worms to break down organic materials in a process called vermicomposting, during which red wiggler worms eat up the waste and excrete the finished vermicompost faster than other composting bins. It also involves less work, as worm bins don’t need to be aerated like others. There’s also an in-ground version that removes the need to empty out the composter, as the materials leach directly into the soil.

Food waste digesters

While food waste digesters don’t technically compost your household waste, they do break it down and create a liquid called “leachate.” The processors include a lower basket buried in your garden where the food breaks down and leaches into the soil, so you wouldn’t need to empty the compost bin yourself. Simply add the waste through a cone placed above ground. Naturally, this is only suitable for backyard composting.

Countertop food waste processors

One of the smaller composters you can get, these are perfect for indoor composting or composting in an apartment. Also known as an electric composter, these grind up and dehydrate the waste. Though not technically compost, the resulting material offers the same benefits as compost, and serves as a faster way to get rid of your food waste.

How to Compost at Home

In additional to your composting materials and compost bin, several tools can be useful for making compost, depending on the compost systems you’re using:

  • Water hose with a spray head
  • Pitchfork
  • Square point shovel
  • Scissors

You’ll need to cut up your grass clippings, kitchen waste, and other organic matter before adding it to the compost heap. If you decide to make your own compost bin, you’ll need a few other tools and materials, such as a drill and wooden pallets.

Once you’ve either made or bought your compost bin, it’s time to get started on the composting process, which differs slightly depending on whether you do so inside or outside, as well as what type of compost bin you use. Generally, it involves a few particular steps:

  1. Buy or make your compost bin and find somewhere to place it
  2. Collect the food scraps and other materials
  3. Add the compost materials in the right mix
  4. Wait and aerate every few days
  5. Remove the compost when it looks like dry, dark soil, and spread across your garden

What to Compost

Homes produce a wide variety of waste materials, and knowing which are compostable materials is pretty important. As long as you get the right mix of brown and green materials, you can compost most household waste:

  • Fruit peels, flesh, and pits
  • Dry grass clippings, yard trimmings, and other yard waste
  • Kitchen scraps
  • Coffee grounds and coffee filters
  • Veggie scraps
  • Tea bags
  • Eggshells
  • Wood ash and wood chips
  • Paper bags
  • Banana peels
  • Nut shells
  • 100% cotton and wool rags
  • Leaves
  • Hay and straw
  • Pine needles
  • Shredded newspaper
  • Sawdust
  • Fireplace ashes
  • Hair and fur
  • Cardboard
  • Paper
  • Corn stalks
  • Wine corks
  • Potted plants

Before adding these materials to your compost pile, chop them up into small pieces so they’ll decompose faster. 

What Not to Compost

Since you’ll be applying your finished compost to your garden and houseplants, knowing what to avoid composting is just as important as knowing what you can compost. Inorganic materials, for example, are an obvious no-no if you want usable compost. These include plastic, glossy paper, synthetic fabrics, and glass.

There are, however, a few natural materials you’ll need to avoid composting. Diseased plants make the top of the list, as plant diseases won’t break down during composting—unless you’re using a hot composting system—and will eventually spread across the soil you add it to, infecting your plants. It’s best to burn these plants to avoid spreading any disease, but check with your local authorities before doing so to make sure it’s legal in your area.

Meat scraps and other animal products should also be left out of your pile, as these also carry the risk of disease, and can attract pests and cause odor.

The compostability of some materials is not as clear cut as others.

While invasive and noxious weeds are compostable and won’t necessarily harm your compost, they can often come back even if there’s only a small part of them left in your compost. You may want to avoid adding weeds and weed seeds to your compost if you don’t want them to end up sprouting in your soil.

Colored newspaper is a bit of a mixed bag, as some of these are compostable while others aren’t. The main difference between these two categories is the thin layers of wax some color newspapers are coated in, which isn’t compostable. If it’s not coated in this, the newspaper can be shredded and composted.

Applying Compost

Finished compost can be applied to any soil, whether it’s a large crop field or small houseplant. Obviously, for use in agriculture you would need quite a lot of compost. For the average person or family, your compost will be adequate for applying to your home garden a few times a year, plenty to enjoy the lusher, greener plants, healthier-looking flowers, and longer bloom times.

Adding compost to your garden is a little more complicated than simply sprinkling it on top, but it doesn’t need to be a stressful process. You’ll need to properly mix it into your soil, about one to two inches of compost for every three to five inches of soil. 

Wrapping Up

Creating nutrient-rich compost is far from complicated once you know what the right materials are. It’s crucial that you avoid adding the wrong materials to your compost pile, so that you can have a healthy, usable compost ready to add to your garden.