How to Compost: What to Use and What Not to Use
What Can You Compost at Home to Nourish Your Garden Soil?
When you start composting, the first real question is simple. What actually goes into the pile? Most home compost works best when it sticks to everyday kitchen scraps and common yard waste. You don’t need to save everything, and you don’t need to guess.
Over time, composting becomes part of the routine. We learn which materials break down quickly and which ones cause problems in the pile. The list below covers the most common materials and whether they belong in your compost.
Kitchen Scraps You Can Compost
Most kitchen scraps break down easily and add valuable organic matter to compost. These materials soften quickly and mix well with yard waste.
Vegetable trimmings, fruit scraps, coffee grounds, tea leaves, and eggshells all belong in compost. These items come from plant material and feed the organisms that break things down. Scraps don’t need to be perfect. Cutting large pieces in half or giving them a rough chop helps speed the process, but compost still works if you add them whole.
Paper coffee filters and plain paper tea bags compost well too. They break down along with the scraps and add carbon to the pile.
Yard Waste You Can Compost
Yard waste makes up a large part of most compost piles. Fallen leaves, grass clippings, spent annuals, and trimmed plant material all break down well when mixed properly.
Dry leaves are especially useful. They balance moisture from kitchen scraps and help keep compost from becoming compacted. Grass clippings add nitrogen, but they work best when mixed with dry material so they don’t mat together.
Weeds can go into compost as long as they have not gone to seed. Once weeds set seed, composting them risks spreading those seeds back into the garden.
Materials You Can Compost in Small Amounts
Some materials compost more slowly or cause imbalance when added in large amounts. Citrus peels, onion skins, pine needles, wood ash and sawdust from untreated wood can go into compost, but they work best when mixed with other materials. Do not compost ash from charcoal, briquettes, or treated wood.
These items break down over time. Adding them in moderation and pairing them with dry leaves or cardboard prevents problems.
What Not to Compost at Home
Some materials cause odor, attract animals, or create issues later when compost returns to the garden. These items do not belong in a home compost pile.
Meat, fish, dairy products, greasy foods, and cooked foods with oils or sauces break down poorly and often draw pests. Leaving these out keeps your compost easier to manage.
Diseased Plants vs Pest Damage
Yard waste from diseased plants should not go into compost. Most home compost piles do not reach temperatures high enough to kill plant pathogens. Composting diseased leaves, stems, or roots can reintroduce disease when that compost returns to the garden.
Signs of disease include leaf spots, mold, rot, wilting, or discolored growth. When a plant shows these symptoms, it is best to dispose of the material rather than compost it.
Insect damage is different. Leaves or stems chewed by insects but otherwise healthy usually compost without issue. If the plant looks healthy aside from pest damage, the material can go into the compost pile.
Paper and Cardboard in Compost
Lots of paper products compost well and help balance moisture. Plain cardboard, paper towels, uncoated paper, and shredded newspaper all break down when torn into smaller pieces.
Glossy paper, heavily inked cardboard, or paper treated with chemicals should stay out. Tearing cardboard and paper by hand before adding it helps prevent clumping and speeds breakdown.
What Can and Can’t Be Composted: Quick Reference
| Material | Compost | Notes |
|---|---|---|
| Fruit and vegetable scraps | Yes | Chop large pieces to help them break down faster. |
| Coffee grounds | Yes | Paper filters can be composted as well. |
| Tea leaves and paper tea bags | Yes | Avoid tea bags made with plastic or synthetic fibers. |
| Eggshells | Yes | Crush lightly so they break down more quickly. |
| Fallen leaves | Yes | Excellent dry material for balancing moisture. |
| Grass clippings | Yes | Mix with dry material to prevent clumping. |
| Plant trimmings and spent annuals | Yes | Only compost healthy plants. |
| Weeds before they set seed | Yes | Do not compost weeds that have gone to seed. |
| Pest-damaged plants | Usually | Safe if plants show no signs of disease. |
| Citrus peels | In small amounts | Break down slowly if added in large quantities. |
| Onion skins | In small amounts | Mix well with other materials. |
| Pine needles | In small amounts | Best when combined with other compost materials. |
| Cardboard and plain paper | Yes, if untreated | Tear into pieces; avoid glossy or coated paper. |
| Wood ash from untreated wood | In small amounts | Mix in well; too much can affect compost balance. |
| Meat and fish scraps | No | Cause odor and attract pests. |
| Dairy products | No | Break down poorly and smell. |
| Oily or greasy foods | No | Disrupt compost balance. |
| Cooked foods with sauces or fats | No | Often contain oils that cause problems. |
| Diseased plants | No | Plant pathogens can survive home composting. |
| Weeds with seeds | No | Seeds may survive and spread in the garden. |
| Charcoal or briquette ash | No | Contains additives and should stay out. |
| Glossy paper or treated wood | No | Coatings and chemicals do not break down safely. |
When You’re Not Sure What to Compost
If a material once grew and shows no signs of disease, it likely belongs in compost. If it smells strongly, contains oil or fat, or comes from a diseased plant, it is better left out.
Over time, you get a feel for what belongs in the pile. When in doubt, stick with healthy plant material and basic kitchen scraps.
If you want to see how compost fits into everyday gardening, our composting guide covers the basics of getting started and using it in the garden.