What is compost?

The City of San Diego’s description of composting states that: “Composting is nature’s way to recycle. It is the controlled natural decomposition of organic material, such as leaves, grass clippings, prunings, and fruit and vegetable scraps. Microorganisms break down these materials into compost, or humus, the nutrient rich soil product that results from proper composting.”

Now that you know what composting is, let’s talk about what can and what cannot be composted.

list of items that can be composted: Fruits, vegetables, peels, rinds, stale bread, cooked and uncooked pasta, tortilla chips, cereal, oatmeal, crushed eggshells, coffee grounds and tea leaves, and paper towels; what cannot be composted: Dairy products, meat and bones, fried foods like french fries, plastics like fruit labels, grease and oil, sugary and processed foods


List of items that can be composted:

  • Fruits and vegetables
  • Peelings and rinds
  • Stale bread and pizza crust (without any meat or cheese)
  • Cooked and uncooked pasta
  • Stale crackers, tortilla chips, cereal, and oats/oatmeal
  • Crushed eggshells
  • Coffee grounds and tea leaves
  • Dryer lint (try to moisten it before adding)
  • Tissues and paper towels (ripped into smaller pieces)

List of items that cannot be composted:

  • Animal products, including: milk, butter, cheese, meat, fish skin, and bones
  • Labels and rubber bands from fruits and vegetables
  • Fat, grease, and oil
  • Items that are fried in oil, like french fries
  • Sugary, processed food
  • Liquids, like soda and juice
  • Pet droppings
  • Large twigs and branches

Debunking Compost

Help reduce waste and put leftover food into compost bins. As stated above, your scraps will naturally get broken down and produce soil that can then be used in areas like USD’s Community Garden behind Mission Crossroads. Below are some dos and don’ts about composting, as well as some responses to myths about it.

  • Compost tumblers should be turned after adding material to them.
  • Although animal products cannot be added to compost, clean eggshells can be added as long as they have been crushed beforehand.
  • Tossing scraps in the compost bin rather than in the trash is helpful but try to shred or cut up what you are adding to help it decompose quicker.  
  • Contrary to popular belief, compost does not smell bad, as long as it is well maintained. If there is too much green or moisture it will cause the bin to smell. To combat this, add some brown material like leaves, cardboard pieces, or shredded paper.  
  • Compost bins don’t attract unwanted animals, as long as bins are kept completely closed and no dairy, meat, bones, fat, or pet manure is added.
  • You can keep a small compost bin in your dorm room or apartment to hold scraps. You should occasionally empty it by adding its content to one of the larger compost bins on campus (see locations below). Your bin won’t smell, as long as you take care of it!



Compost locations at USD (restricted use):

  • Compost:
    • SOLES (behind Mother Rosalie Hill Hall)
    • Community Garden (behind Mission Crossroads)
    • Alcala Vista (near Palomar Hall) 


  • Vermicompost:
    • Manchester Family Child Development Center
  • Green Waste:
    • Near Softball field 
    • Behind Alcala Park
composting locations on USD campus