Aerobic Composting Mistakes: Essential Fixes

Are you trying out aerobic composting and running into a few snags? It’s totally normal to hit a few bumps when you’re starting something new. Sometimes, it feels like your compost pile just isn’t working right, and that can be frustrating. But don’t worry! With a few simple fixes, you can get your compost cooking again. We’ll walk through the most common aerobic composting mistakes and show you exactly how to fix them. Let’s turn those compost woes into wins!

Common Aerobic Composting Mistakes (And How to Fix Them)

Composting is a fantastic way to reduce waste and create nutrient-rich soil for your garden. Aerobic composting, which relies on oxygen-loving microbes, is generally faster and produces less odor than other methods. However, beginners often make a few key mistakes that can slow down the process or even cause it to fail. Let’s dive into these common blunders and how to easily set them right.

Mistake 1: Not Enough Airflow (Or Too Much!)

Aerobic composting loves air. The tiny organisms that break down your organic matter need oxygen to live and work their magic. If your pile is too dense or lacks aeration, it can become anaerobic (lacking oxygen), which leads to slow decomposition and smelly results. On the flip side, if you’re constantly turning a very dry pile, you might be losing too much moisture and heat, slowing things down.

Why It Happens:

• Compost bin is too tightly packed.
• Lack of “brown” materials like leaves or cardboard, which create air pockets.
• Not turning the pile regularly enough.
• Turning the pile so vigorously that it dries out too quickly.

The Fix:

The sweet spot is a pile that’s moist but not soggy, and airy enough for oxygen to circulate. You can improve airflow by:

• Choosing the right bin: Bins with built-in ventilation holes are great. If you have a DIY pile, make sure it’s not a solid block.
• Layering correctly: Alternate your “greens” (food scraps, grass clippings) with “browns” (dry leaves, shredded paper, cardboard). Browns act like little sponges and create air pockets. A good ratio is roughly 2-3 parts browns to 1 part greens.
• Turning your pile: Aim to turn your compost pile every 1-2 weeks. You can use a compost fork or aerator tool. Mix the outer layers into the center and vice versa.
• Monitoring moisture: When you turn, squeeze a handful of compost. It should feel like a wrung-out sponge – damp, but no water should drip out. If it’s too dry, add some water as you turn. If it’s too wet, add more brown materials.

Mistake 2: The Wrong Moisture Level

Moisture is crucial for decomposition. Too little and the microbes dry out and become inactive. Too much and the pile becomes waterlogged, squeezing out air and leading to anaerobic conditions (smelly!).

Why It Happens:

• Adding too many wet “greens” without enough “browns” to absorb moisture.
• The compost pile is exposed to excessive rain without cover.
• Not watering a pile that’s too dry, especially in hot or windy conditions.

The Fix:

The ideal moisture content for aerobic composting is often described as being like a wrung-out sponge. Here’s how to achieve it:

• Balance Greens and Browns: This is your first line of defense. Browns (carbon-rich) absorb excess moisture, while greens (nitrogen-rich) provide it. If your pile is too wet, add more browns. If it’s too dry, add more greens and water.
• Cover Your Pile: If you live in a rainy area, a tarp or lid can protect your compost from getting soaked. Make sure the cover still allows for some airflow.
• Add Water When Needed: In dry climates or during hot streaks, you’ll need to add water. Water the pile slowly as you turn it, aiming for that “wrung-out sponge” feel.
• Improve Drainage: If your bin sits in a spot that collects water, ensure it has good drainage. You can place it on a layer of gravel or wood chips.

Mistake 3: Adding the Wrong Materials

While composting is a great way to handle kitchen and yard waste, some items can create problems. Certain things can attract pests, smell bad, or simply won’t break down effectively in an aerobic system.

Why It Happens:

• Adding meat, dairy, or oily foods which attract pests and create odors.
• Including diseased plants that could spread problems to your garden.
• Adding pet waste from carnivorous animals (dogs, cats), which can contain harmful pathogens.
• Composting chemically treated yard waste.

The Fix:

Stick to the basics and avoid these common culprits. Generally, you want to compost:

• “Greens” (Nitrogen-rich): Fruit and vegetable scraps, coffee grounds, tea bags, grass clippings, plant trimmings.
• “Browns” (Carbon-rich): Dry leaves, straw, shredded newspaper, cardboard (uncoated), twigs, sawdust (from untreated wood).

Avoid these items:

• Meat, fish, bones, and dairy products
• Oily or greasy foods
• Diseased plants or weeds that have gone to seed
• Pet waste (from cats and dogs)
• Coal or charcoal ash
• Glossy or coated paper/cardboard
• Inorganic materials (plastic, metal, glass)

For a more detailed list, check out the EPA’s composting guidelines. They offer a comprehensive breakdown of what to compost and what to avoid.

Mistake 4: The Pile is Too Small (Or Too Big!)

Composting is a biological process that works best when the pile reaches a certain size and temperature. Too small, and it might not heat up enough to decompose efficiently. Too large and it can become compacted and difficult to manage.

Why It Happens:

• Not gathering enough materials before starting a new pile.
• Using a bin that is too small for the amount of waste generated.
• Trying to compost an enormous volume of material at once without breaking it down.

The Fix:

The ideal size for a compost pile is typically about 3 feet x 3 feet x 3 feet (1 cubic yard or meter). This size allows the pile to heat up effectively, which speeds up decomposition.

• Build Up Your Materials: If you don’t have enough material to start, collect your kitchen scraps and yard waste in a separate container. When you have a good amount, start your pile.
• Use Appropriate Bins: If your waste volume is higher than a small bin can handle, consider a larger bin or a freestanding pile if allowed on your property.
• Manage Large Volumes: If you have a massive amount of yard waste, consider creating multiple smaller piles or breaking down the material before adding it. Chop larger items into smaller pieces to speed up decomposition.

Mistake 5: No Nitrogen “Greens”

Composting relies on a balanced mix of “greens” (nitrogen-rich) and “browns” (carbon-rich). If you have too many browns, your compost will break down very slowly. It’s like trying to run an engine with only fuel but no spark!

Why It Happens:

• Primarily adding only yard waste like dry leaves and grass clippings but rarely food scraps or other nitrogen sources.
• Not understanding the role of nitrogen in the composting process.

The Fix:

Ensure you have enough nitrogen-rich “green” materials. These provide the protein and energy that the microorganisms need to thrive and multiply.

• Add Kitchen Scraps: Fruit and vegetable peels, coffee grounds, tea bags, and even spoiled food (that isn’t meat or dairy) are excellent sources of nitrogen.
• Include Fresh Grass Clippings: In moderate amounts, fresh grass clippings are a fantastic nitrogen source. Be sure to mix them in well with browns to prevent matting and odors.
• Consider Manure: Aged manure from herbivores (like cows, horses, rabbits) is another good nitrogen source.
• The Correct Ratio: Remember the general guideline: 2-3 parts browns to 1 part greens. Adjust as needed based on how your compost is performing. If it’s slow and cool, you probably need more greens.

Mistake 6: Not Enough Carbon “Browns”

Just as too few greens can be a problem, too few browns can lead to a slimy, smelly compost pile. Browns provide the carbon that the microbes use for energy and also help create the airy structure needed for oxygen circulation.

Why It Happens:

• Composting mostly food scraps and grass clippings without adding enough dry materials.
• Not realizing the need for bulky, carbon-rich materials.

The Fix:

Make sure you’re regularly adding carbon-rich “brown” materials. They are essential for balancing the nitrogen and preventing a soggy mess.

• Stockpile Browns: Save dry leaves in the fall, collect shredded paper and cardboard scraps year-round.
• Use Various Browns: Shredded newspaper, torn-up junk mail, cardboard boxes (unwaxed), straw, wood chips, and sawdust from untreated wood all work well.
• Break Them Down: Chop or shred larger brown materials (like cardboard) to help them decompose faster.
• Add Them During Layering: When you add your kitchen scraps (greens), make sure to cover them with a layer of browns. This helps manage moisture and airflow.

Mistake 7: The Pile Isn’t Hot Enough (Or Too Hot!)

A “hot” compost pile (around 130-160°F or 55-70°C) decomposes much faster and kills weed seeds and pathogens. If your pile isn’t heating up, it’s often due to issues with aeration, moisture, or the green-to-brown ratio. If it gets too hot, it can kill beneficial microbes, and decomposition can stall.

Why It Happens:

• Too Cool: Pile is too small, lacks enough nitrogen (greens), too much moisture, or poor aeration.
• Too Hot: Too much nitrogen, pile is too dense, or not enough airflow.

The Fix:

Managing the temperature is key to efficient composting. You can use a compost thermometer to monitor it, though you can also gauge heat by feeling the center of the pile.

• For a Cold Pile:
  • Add Greens: If it’s low on nitrogen, add more kitchen scraps or grass clippings.
  • Add Water: If it’s dry, moisten it with water as you turn.
  • Turn It: Introduce air by turning the pile.
  • Build It Bigger: If the pile is too small, add more material.
• For an Overheated Pile:
  • Turn It: This is the most important step to release excess heat and introduce air.
  • Add Browns: If it’s too nitrogen-rich, add a good amount of carbon-rich brown materials.
  • Check Moisture: Ensure it’s not too wet.

Mistake 8: Neglecting to Turn or Aerate

Aerobic composting relies on oxygen. If you just pile materials up and leave them, the center can become compacted and anaerobic, leading to slow decomposition and unpleasant odors.

Why It Happens:

• Thinking composting is a “set it and forget it” process.
• Lack of the right tools (like a compost fork) to easily turn the pile.
• Simply forgetting or not having a turning schedule.

The Fix:

Regular turning is non-negotiable for active aerobic composting. It remixes materials, adds oxygen, and helps manage moisture and temperature.

• Establish a Schedule: Aim to turn your pile every 1-2 weeks. More frequent turning (weekly) will speed things up significantly.
• Use the Right Tools: A long-handled compost fork or a pitchfork works well for turning. Compost aerator tools are also designed specifically for this task and can be easier on your back.
• Mix Thoroughly: When you turn, try to move material from the outer edges into the center and bring the inner material to the outside. This ensures everything decomposes evenly.
• Check Moisture While Turning: This is the perfect time to assess and adjust the moisture level.

Troubleshooting Table: Quick Fixes for Common Issues

Here’s a quick reference guide to help you diagnose and fix your composting problems:

Problem	Likely Cause	Quick Fixes
Smelly (Ammonia/Rotten Egg)	Too much nitrogen (greens), too much moisture, lack of air	Add browns (leaves, cardboard), turn pile, add dry materials
Not Heating Up	Pile too small, not enough nitrogen (greens), too dry, poor aeration	Add greens, moisten pile, turn pile, build up to 3x3x3 feet
Attracting Pests (Rodents, Flies)	Adding forbidden materials (meat, dairy, oily foods), exposed food scraps	Bury food scraps deep in the pile, cover pile, avoid forbidden items
Decomposing Very Slowly	Too cold, too dry, not enough nitrogen, materials too large	Add greens, moisten pile, turn pile, chop materials smaller
Slimy or Soggy	Too much moisture, too many greens, not enough browns, poor aeration	Add dry browns, turn pile, ensure good drainage, avoid overwatering

FAQ: Your Aerobic Composting Questions Answered

Got more questions? We’ve got answers!

Q1: How often should I turn my aerobic compost pile?

A1: For faster composting, turn your pile every 1-2 weeks. If you’re more patient, turning less frequently (once a month) will still work, it will just take longer.

Q2: My compost smells like ammonia. What did I do wrong?

A2: An ammonia smell usually means there’s too much nitrogen (greens) in your pile, or it’s too wet. Add more dry brown materials like shredded cardboard or leaves, and turn the pile to help it aerate.

Q3: Can I compost grass clippings?

A3: Yes, grass clippings are great “green” material! However, add them in thin layers and mix them with browns. Thick layers can mat down, starve the pile of oxygen, and cause odors.

Q4: My compost pile is too dry. What should I do?

A4: If your compost feels dry and crumbly, it needs more moisture. Moisten it by slowly adding water as you turn the pile. Aim for that “wrung-out sponge” consistency.

Q5: How do I know when my compost is ready?

A5: Finished compost will be dark, crumbly, and smell earthy, like a forest floor. You shouldn’t be able to recognize the original materials you put in. It will also be cool to the touch.

Q6: I live in an apartment. Can I still do aerobic composting?

A6: Absolutely! Small-scale aerobic composting is possible. You can use a sealed compost bin designed for indoor use (like a tumbler or a worm bin, though worm bins are technically vermicomposting, they are a fantastic aerobic-based system for apartments) or a small, well-ventilated bin on a balcony.

Q7: Do I need special tools to start composting?

A7: While specialized tools like compost forks or aerators can make the job easier, you can start with everyday