What to Compost and What Not to Compost

food waste

Turning kitchen trash into a nutrient-rich garden helper is a great way to save money and feed your plants. Composting is easy and fun, and you might be surprised what you can throw into the pile to help your garden grow stronger, healthier, and more eco-friendly. It starts with learning what to compost and what not to compost.

What Is Composting?

Basically, composting is the method by which waste matter is converted into usable, mineral-rich fertilizer through microbial activity.

You can use compost to supercharge your garden, since the tiny organisms that drive this process are very good for plants, and they help support the circle of life in your local ecology.

You can compost indoors in a container, or outdoors in a bin or a pit. Most organic materials are good for compost, from food scraps to yard waste and even some kinds of trash.

Picking what to compost sometimes comes down to how long a substance will take to decompose—banana peels will break apart in a few months, while paper might take a year or more.

Over time, bacteria feed on this organic matter and increase its nitrogen, phosphorus, and potassium ratio. Sometimes, worms can be added to the compost to speed up the process (this technique is called vermicomposting).

Compost helps soil retain its moisture, which further enhances the growth, health, and even flavor of your plants. Compost further reduces the need for chemical fertilizers and reduces your carbon footprint.

In fact, the act of composting can allow you to remove up to 500 pounds of organic matter from your household waste per year.

Composting for Beginners

wood compost bin with food waste

You can start a compost pile with minimal time, effort, and cost by building a simple heap of stuff The pile will shrink as it decomposes. To avoid bad smells and sights, consider building a container for your heap.

You can also build a simple wire bin, or you may choose to construct a more complex system. You can also build a compost heap using a plastic trash receptacle. Simply start filling up a large trash can with your compost material.

If you choose to use a bin, you can find one at your local hardware store. Many people do prefer to use one because this hides the rotting waste, especially valuable if you have a smaller backyard.

Stationary compost bins have the largest capacity. Typically, they're a dark color to help attract and maintain heat. They also have a lid to prevent yard critters from sneaking in.

These also possess one or two doors that allow users to remove compost that is ready for use, which makes them very straightforward and simple.

The length of time it takes for compost to be ready differs from area to area as the climate has an effect and whether or not you frequently “turn” the material, which determines how quickly it will be ready.

Bins might make it more difficult to turn the inside matter, meaning you may need to wait longer for the finished product.

The other common option is a compost tumbler, which holds slightly less material but gets you an end result quicker. These containers make it convenient to turn your compost matter to speed up the process.

Where to Compost

You should locate your compost pile in a cool and dark outdoor spot. It's best to find a place under a tree with low acidity.

You want it to be near a water source, and you don’t want it to be too close to gathering areas. Compost can have a quite strong smell, and it's very worm-friendly, so you don’t want it right next to your barbeque area.

What to Compost

Common Items You Can Compost

  • Food scraps
  • Grass
  • Leaves
  • Plant trimmings
  • Paper
  • Cotton

food waste for compost

Yard Waste

Whatever yard waste you would typically throw out can be used for your compost pile. Keep in mind that moist greens produce odors. Never include sick plants, acidic plants, or poisonous plants in your compost pile.

Brown Materials

Items that go into the compost pile are often classified as “brown” materials and “green” materials.

Typical brown material is bark and sticks. Certain paper products can also be added to the compost pile. Toilet paper rolls, cardboard, newspaper, coffee filters, toothpicks, all of these items are brown materials that can go into the compost pile.

Paper can also go into the compost bin, but avoid recycled paper, which should go out with your household recycling instead.

Along the same lines as material that comes from trees, you can also include products made from other plants. Cotton is a good example, but you should only include organic cotton without dyes.

Cotton balls, strips of sheets, and old shirts all make the cut. Similarly, hemp, jute, and burlap can all be added to the pile as brown material.

Green Materials

green yard waste

What can you compost that qualifies as green material? Grass clippings offer essential nutrients to the mix but make sure your layers of grass are thin and consistent when added to the pile for the best compost recipe.

You can also include hay and bedding from herbivore animals like guinea pigs, along with their waste. Do not include animal manure from dogs and cats.

Be sure to recycle your garden plants back into the composter once the harvest is complete. Corn husks and stalks, tomato plants, herbs, flowers, and other living plants are just a few examples of what can go into the compost pile.

Organic Material

What are the best things to put in compost? It can be difficult to know what can and cannot go in a compost bin. But in many cases, your kitchen scraps are ready to be added in as is.

Take advantage of your food waste. The compost pile loves eggshells, coffee grounds, fruit pits, veggie stalks, banana peels, onion skins, nutshells, grains, tea, and basically any non-animal, natural product.

All the stuff you would normally throw away while you’re cooking can go into the compost bin, as long as it’s food and not an empty tin can. Those should still be town away normally.

If you want to know what to put in compost bin projects, ask yourself if it’s a natural material. Has it been dyed or altered? Does it contain plastic, metal, or something else that doesn’t recycle easily? What goes in compost?

Natural materials that you would normally throw away. Instead of tossing them, put them to work. You’ll create less waste, which helps the planet, and you’ll be brewing up some good nutrients for all your garden and landscape areas.

Unusual Compost Materials

There are some household items you may not have considered suitable for the compost heap. Dryer lint is one example. You can also add fire ashes as long as the wood you burned was chemical-free.

In other words, avoid the ashes from garbage burns but toss in those from the fireplace. If you’re wondering should I put ashes in my compost, the answer is yes.

Loofahs and natural sponges are other little-known compost ingredients. Also, when you’re cleaning the house, feel free to dump the swept-up dirt, dust, and even pet hair into the compost pile.

You can even put your full vacuum bag in as long as the contents are mostly dust and dirt, rather than plastic toys and pieces of metal and rock.

What Not to Compost

  • Meat
  • Dairy
  • Rocks
  • Roots
  • Chemicals
  • Plastic

food waste meat

Don't compost meats, fats, or animal products like dairy. Also keep out rocks, the roots of garden weeds, dairy waste, synthetics, treated wood material, bones, and anything that has been exposed to toxic chemicals.

All of this stuff is not good for your compost, and it won’t break down and turn into the nutrients that you need to enrich your garden.

Do not add any plastic, foil, or other non-organic materials. If it did not come directly from the Earth, it should not go back into it.

Also, avoid plants that have any kind of disease, and avoid weeds and grass clippings that contain pesticides.

Can You Compost Charcoal Ash?

Yes, you can compost charcoal ash, just don't add too much at one time. Since it's carbon-rich, charcoal ash can add powerful nutrients to your compost brew. As wood ash is compostable, this is also true of other wood products, including charcoal.

There are two conditions to this, however. First, the charcoal itself should be basic wood. Beware of preservatives and other additives to make the product burn more efficiently, as these may not be environmentally compatible.

The second condition is that charcoal ash for compost itself may only be used to a limited degree, around one cup per foot of compost. Large amounts of wood result in a loss of nitrogen in the soil.

As with wood ash, only use a similar cupful of ash for each foot of compost. So long as you don’t barbeque every day, charcoal BBQ ash is perfectly safe to put into your compost pile or bin.

Tips for How to Compost at Home

A healthy and well-maintained pile will not attract insects.

Meats and fats attract rats, so keep them out.

Moisture must be regulated carefully. Excess moisture causes the pile to rot, while insufficient moisture prevents it from breaking down.

The process slows in cold weather.

Roughly even layers will mix better.

Cut up large items to help them break down faster.

Mix food waste under green waste like grass clippings to minimize smells and bugs.

The easiest way to tell it's ready is that it looks like very dark soil, rather than a mixed-up pile of materials.

Compost Recipe

While there's no exact mixture for compost, the greater the amount of green materials (such as grass and nitrogen-rich food scraps), the better the results will be. Brown materials (such as dry greens and wood) add carbon.

Compostable waste examples include soil, bone meal, blood meal, ashes, and manure. All of these can be added to your compost.


Turning waste materials into compost reduces the amount of waste you’re adding to landfills. And in time, compost becomes an extremely nutrient-rich material that keeps garden and landscape areas healthy.

This helps to reduce or even eliminate your need for fertilizer and mulch. That saves you money, too.