What You Should Know about Composting Kitchen Scraps

Composting kitchen scrap

What kitchen scraps are safe for the compost? Look at this beautiful material! Photo credit: Christian Guthier Flickr 

Whether you garden organically or not, your garden will appreciate some composted kitchen scraps. One of the advantages of using vegetable and fruit waste is that you reduce your waste contribution to landfills. One of the disadvantages is that using the wrong kitchen scraps can deter plant growth. Another problem is that kitchen waste is “green” matter and the compost process needs approximately 3 parts carbon to 1 part green matter.


What kitchen scraps are safe for composting?

Most of the fruits and vegetables that we eat are safe for our garden and house plants. They need to be aged, or “composted”, in order to not cause harm to the plants. Some experienced composters recommend that you do not put seeds, such as apple seeds, pumpkin seeds, and others, in your compost because they will sprout.

Here is a partial list of good foods for composting:

  • Apples
  • Bananas
  • Berries
  • Breads
  • Cabbage
  • Carrots
  • Celery
  • Cereals
  • Cherries
  • Coffee Grounds
  • Grains
  • Grapefruit
  • Lettuce and Other Leafy Vegetables
  • Melon Rinds
  • Mushrooms
  • Orange and Other Citrus Peels
  • Pasta
  • Pears
  • Pineapple
  • Potatoes
  • Pumpkin Shells
  • Squash
  • Tea
  • Tomatoes
  • Turnip and Other Root Vegetables
  • Turnip and Other Root Vegetable Leaves


You should never add these if they have sauce or dressing made with oils, cheeses, or meat products.


You can add cooked or uncooked foods, such as vegetables, pasta, grains, etc., if they do not have a lot of oils or any meat-products. For example, you could add your spaghetti and tomato sauce, but do not add your spaghetti and meatballs.

Essentially, almost any food that is not dairy, oil-based, or meat-based makes a good fuel for your compost. When in doubt, you can contact your local county agent to learn what is acceptable. Keep in mind that people rarely agree so you can experiment with different foods. One composter may not add breads but another may use a lot of bread products. Composting is a trial-and-error process.

You can find items in surprising places. For example, you can add a spent floral arrangement. Or sawdust from untreated lumber. Some people add the lint from their vacuum cleaners and from the dryer.


Never add these when composting kitchen scraps

  • Bones
  • Dairy, such as
    • Butter
    • Cheese
    • Ice Cream
    • Milk
    • Sour Cream
    • Yogurt
  • Fish Scraps
  • Foods Containing Oils or Fats such as
    • Margarine
    • Mayonnaise
    • Olive Oil
    • Peanut Butter
    • Salad Dressing
    • Vegetable Oil
  • Lard
  • Meat Scraps


Many composters do not add onion or members of the onion family (garlic, leeks, shallots, etc.) to their compost. The onion family, called the Allium family, have a very strong odor. Decaying onions can attract pests and create a stinky compost. Onions also have a tendency to resprout while composting. If you add onions, garlic, and other odorous matter, chop it into fine pieces or process it in a blender, and thoroughly mix it into the carbon matter.


You can and should add nonfood items.

The kitchen can be a source of carbon materials. Remember that the compost process needs a mixture that is approximately a three-to-one mixture with the drier carbon products being the greater mass. Often, it is hard to find enough carbon matter to make a good mixture. Shredded newspaper, junk mail, old bills, and other papers are carbon.

Your nonfood items cannot have a waxy coating, such as some food packaging, or have meat or oil residue. This means that paper plates, pizza boxes, and waxed paper are not suitable. Also, you should not use paper towels that you used to wipe up greasy messes.

  • Cardboard Packaging
  • Coffee Filters
  • Eggshells, crushed
  • Newspaper
  • Paper
  • Paper Lunch Bags (if clean of grease)
  • Paper Mache Egg Cartons
  • Paper Towels and Paper Towel Rolls
  • Tea Bags
  • Wine Corks, crushed or chopped
  • And more carbon-based materials



This gardener is thrilled the texture of his homemade compost. Photo credit: normanack Flickr 

Understanding the compost process is the key to success.

Experienced composters know that kitchen garbage is not the stuff that produces soil. The carbon matter is the end product that you can hold in your hand. So what does the kitchen scrap do? It nourishes the microorganisms that fuel the process. You need a blend of carbon materials and healthy microorganisms to create great fertilizer.

Do not add your kitchen scraps directly to your garden. As explained above, it does not add nutrients to your soil. Generally, scraps – even vegetable scraps – added to the garden attract unwanted guests, such as raccoons, bears, and more. It will also stink as it breaks down.


Some items are not worth the effort.

You want your end product to be rich, loamy soil that you can use in your garden and houseplant containers. Some items, such as nutshells, take too long to break down. Many gardeners avoid adding them. Here is a short list of problem items:

  • Avocado Pits
  • Corn Cobs
  • Nut Shells
  • Peach and Other Fruit Pits


My compost bin smells and is attracting flies.

If your compost mixture is too heavy with low-nitrogen materials, such as fresh plant material, your compost will “sour.” Are you following the suggested ratio of 3:1? You need more carbon, or “dry”, substance than the kitchen scrap. Boost your carbon with shredded newspaper and other things from the nonfood list.

Some people do not add banana peels or citrus rinds because sometimes they have fruit fly eggs on the skins. Others add them without problems. You need to judge whether you want to try these items.


Why can’t I add pet waste if I can add cow manure?

Isn’t it the same? No. Composted manure comes from herbivores, not carnivores, like dogs and cats. The droppings from dogs, cats, birds, and other animals can contain pathogens. Commercial composters can usually obtain enough heat in their process to kill these disease organisms, but home processors cannot.


The Indians used fish as a fertilizer so why can’t I compost with it?

It is true that the Indians used fish as a fertilizer. However, they buried the fish in a deep hole before planting the seeds on top. No one knows how many plants they lost due to raccoons and bears. I can just imagine the heartache of finding a pest has dug up the fish to have a tasty meal! Aside from the vermin problem, your compost pile is above ground and it will stink as the fish decays.

banana peels are tough

Tough foods like banana peels can ruin a blender. Chop them up to make your kitchen compost puree. Photo credit: Claire Knights Flickr 

One last tip.

Many people hasten the composting process by chopping their waste into fine pieces or even pureeing them in a blender. Other composters do not feel this is necessary. A couple of local gardeners followed the advice on a website and added the blended mixture directly to their garden beds. Animals dug up the plants near the pureed kitchen scraps! Both gardeners are adding the juicy waste to their compost piles now.


Again, composting is a process of trial-and-error and you need to find the method that works best for you.


Composting can be a fun and rewarding process. Using your kitchen waste as your green material helps keep it out of our country’s landfills. The Environmental Protection Agency (EPA) estimated that Americans throw out 35 million tons of food annually. In landfills, the rotting food creates methane gas, which is about 25 times as potent as carbon dioxide, and takes up acres of valuable land. It is the greatest percentage of landfill matter.


Home Composting Materials from Wisconsin Department of Natural Resources (WIDNR) 

News Releases By Date 03/31/2016 “EPA Recognizes University of Arizona for Efforts to Reduce Wasted Food” 

A Basic Guide for Beginning Gardeners by Terrie Brockmann

Share with your friends
To report this post you need to login first.

Leave a Reply

Your email address will not be published. Required fields are marked *