Anyone who has read about gardening knows that compost is a good thing. Compost provides and holds essential nutrients for plant growth, improves soil structure, helps retain water and improve soil aeration, and it attracts beneficial microorganisms to the soil. But sometimes even the experienced gardener may experience what I call “compost fail.” Symptoms of compost fail include material that never decomposes, a pile that stinks, or a pile that attracts vermin. Here are common reasons why compost piles fail to produce the black gold you’re striving for, and what you can do to fix a diagnosed compost problem:
Moisture: Compost should have the moisture level of a rung-out sponge; wet but not soggy. A pile that is too wet can become stagnant, while one that is too try won’t decompose at all.
Aeration: Proper air circulation is key to allow a compost pile to break down. A pile can easily be aerated by turning it over with a pitchfork.
Microorganisms: Without microorganisms, you will not have decomposition. A successful compost pile will get hot because these small critters are doing their job decomposing your yard and kitchen waste, and producing energy (heat) in the process. Make sure your pile is in direct contact with the soil to allow the natural microorganisms and worms to gain access to your pile and help it decompose. And remember that small insects, like ants and pill bugs, help the decomposition process.
Size: For a compost pile to build up momentum, it needs to be at least 3′ by 3′ in diameter. A pile that is smaller than this just won’t be able to sustain the biological activity responsible for decomposition.
Brown and Green: Compost piles need both brown materials (autumn leaves, dead plants, sawdust, cardboard, shredded paper, egg shells, etc) and green materials (grass cuttings, chicken or rabbit manure, fruit and vegetable scraps, coffee grounds, green plant material, etc.) to thrive. Brown material is the “fiber” of the pile, and provides carbon to your mix. The green material provides the nitrogen needed for plant growth, and is responsible for generating the heat in your composting pile.
Harmful ingredients: Here is a list of things that should never be included in your compost pile. These materials can attract unwanted animals and negatively affect the health of your compost and, ultimately, your plants:
- Dairy products
- Meat or fish products
- Oils, grease, or fats of any kind
- Dog or cat waste
- Diseased or insect-ridden plant material
- Charcoal ash
- Any material from black walnut trees
Some common compost pile problems that you might come across include lack of decomposition, a pile that stinks, or a pile that attracts animals, such as rats or dogs.
My pile isn’t decomposing!
- Make sure there is enough water (but not too much) so the pile is about as damp as a rung-out sponge. Water your pile if it seems too dry, or use a more closed-in container to hold the compost.
- A pile that is too wet should have brown material, such as dried leaves or shredded branches included to absorb the excess moisture.
- If there is a barrier between your compost and the bare earth, remove it.
- If the pile seems very thick or dense, aerate it. Compost won’t decompose without proper aeration.
- Material that is too large will decompose very slowly in a compost pile. Make sure the pieces are small enough to decompose quickly.
My pile smells awful!
- Your pile may be too wet; add brown material to soak up the excess moisture.
- A pile that is poorly aerated will result in anaerobic conditions, which can smell. Aerate the pile well.
- If you included any dairy, meat or fish products, grease, or oil remove these items immediately, and consider disposing of the compost and starting over. These are not healthy ingredients to include in a compost pile and, when they start to rot, will cause serious problems, including a bad smell.
My compost pile attracts vermin!
- Make sure you are not including any dairy, meat or fish products, grease, or oil that attract vermin.
- When you add vegetable or fruit scraps to your pile, make sure you bury them a bit in the pile instead of dumping them on the surface.
- Consider a bin with enclosed sides and top (but not solid enough to prevent aeration) to provide a barrier to critters.