Composting is the process of turning food and landscaping scraps into nutrient-rich organic soil matter called “humus.” The idea is to return the nutrients that went into growing plants back to the soil to grow a new generation of plants. Let’s take a more in-depth look at what to add, and what NOT to add, to your new compost! We’ve included some background information to help you develop the best result possible. Remember, this is a biological process and will take some time! See you in the garden!
What to Add:
Brown Matter (Carbon Sources)
- Cardboard added in moderation should be shredded and is best wet
- Hay & Straw
- Leaves – avoid any diseased or troubled plants
- Nutshells & Nuts but avoid walnuts and walnut shells (see Compost No-Nos)
- Paper should be shredded, however avoid glossy print
- Paper Towels from drying water only
- Sawdust in moderation (it’s heavy in carbon), but never from treated or painted wood
- Wood Chips from untreated wood
Green Matter (Nitrogen Sources)
- Coffee Grounds and Coffee Filters as long as the filters are biodegradable
- Fruit Scraps & Peels – stay away from citrus
- Grass Cuttings in moderation, but no nut grass, crabgrass, or bermuda grass
- Pet Fur when scattered evenly
- Tea Leaves & Tea Bags as long as the bags are biodegradable
- Vegetable Scraps & Peels – avoid dense items like corn cobs and hard lettuce cores
Neutral Items that are Great for Compost
- Cotton Rags that are shredded – it’s best if they are organic
- Eggshells that are finely ground
- Wood Ash in moderation, too much can suppress the composting process
What to Avoid:
Harmful Bacteria & Pest Attractors
- Dairy will attract animals and can be harmful to compost
- Meat & Seafood Scraps contain oils harmful to compost and will attract animals
- Oil or any Food Cooked in Oil will harm worms and disrupt soil moisture levels
- Pasta, Bread, & Rice encourage the wrong types of bacteria and attract pests
- Pet Waste can contaminate compost with unwanted organisms and are a health risk
- Canned Food, Sauces, & Processed Foods – compost only raw, untreated produce
- Glossy & Coated Paper both contain printing chemicals that are harmful to worms
- Paint & Varnish
- Produce Stickers containing glue
- Sawdust from treated or pressed wood.
- Synthetic Fertilizers and Fertilized Plants should never be added to organic compost
Other Compost No-No’s
- Ash from Coals & Briquettes will smother your compost
- Branches will not break down easily – chip them or avoid
- Citrus is too acidic for your compost and will hurt your worms
- Dense Produce Scraps such as corn cobs or hard lettuce cores are hard to break down
- Diseased or Poisonous Plants may contaminate your garden even after composting
- Onions, Garlic, & Spicy Foods are too acidic and will harm your worms
- Walnuts & Walnut Shells contain a chemical that may be harmful to future plants
- Weeds aren’t recommended – they may not be killed completely in compost process
Tips and Tricks:
- Chop most items to 2” or under, leaves/yard waste can be slightly larger.
- Cover your compost, especially in the rain!
- Moisture Check: Pick up a fist full of compost and squeeze tightly. More than one drop of water? Needs drying out. No moisture at all? Needs water added.
- Continue to maintain a balance of nitrogen (“greens” like grass clippings and food scraps) and carbon sources (“browns” like straw and leaves) regularly.
- When finished, your compost should look, feel and smell like rich, dark soil. You should not be able to recognize any items you originally placed in your bin.