For years, I looked at my compost bin as if it were a magic box. I threw in my vegetable peelings and dead leaves and waited patiently for nature to do its work. Except that sometimes… nothing happened! Or worse, it stank to high heaven and I wondered if I had created a little horror laboratory in my backyard.
With summer here, providing optimal conditions for our decomposing microbes, now is the perfect time to understand why our compost is acting up. Once you understand the science behind it, everything becomes so much simpler! So here’s your ultimate guide, the ABCs of composting!
Portrait of Compost on Strike, or Pandora’s Box!
You know that feeling of discouragement when you lift the lid of your compost bin and discover… the same wilted lettuce you threw in three months ago? Or that swampy smell that makes you recoil? Or worse: the cloud of flies that gets in your nose as they fly away?
A healthy compost smells like a forest after the rain. It’s teeming with life (that doesn’t get up your nose). The temperature rises, the materials decompose, and after a few months, you get that “brown gold” that all gardeners dream of. But when it doesn’t work, it’s often because we’ve neglected one of the essential elements for our microscopic workers.
The good news? A dysfunctional compost pile is almost always fixable! And it’s much less complicated than you might think.
The Science Behind Compost That Works
Compost Workers: Microorganisms
A handful of healthy compost contains between 5 and 7 billion bacteria! It’s a bit like having an entire planet working for you, 24 hours a day, transforming your waste into humus. Take it: you are the divine entity of these microbes! A god who rules over your little world! Amen!
These microorganisms follow a well-orchestrated process. First, mesophilic bacteria (which like temperatures between 20 and 45°C/68 and 113°F) attack easily digestible sugars and proteins. Then, when the temperature rises to between 50 and 70°C/122 and 158°F, thermophilic bacteria take over to break down tougher materials.
Fungi also play a crucial role: they attack the materials that bacteria cannot break down, but they cannot survive above 50°C (122°F). This is why they are mainly found on the edges of compost, where it is cooler.
2. The Magic Ratio: Carbon vs Nitrogen (C/N)
Ah, the famous C/N ratio! If you’ve ever read about composting, you’ve bound to have heard of it. In concrete terms, it means that your mixture should initially contain between 25 and 35 times more carbon than nitrogen (by weight). When the compost is mature, this ratio will have decreased to 10-15 times more carbon than nitrogen.
But don’t worry, you don’t need to get your calculator out every time you compost! In practice, mix about 2 parts nitrogen-rich material (the “green” stuff like vegetable peelings and grass clippings) with 1 part carbon-rich material (the “brown” stuff like dead leaves, cardboard, and shredded branches). This proportion will naturally give you the right ratio.
Why These Proportions?
Bacteria need carbon as an energy source (much like we need carbohydrates) and nitrogen to make their tiny bacterial proteins. Too much carbon, and they lack building materials. Too much nitrogen, and they get overexcited but quickly burn out! And if you’re wondering why we talk about 30 times more carbon in theory, but recommend more green materials in practice, it’s because “green” materials already contain a lot of carbon—and dead leaves are much lighter than your carrot peelings!
3. Heat Is Important… but Not Required!
Compost in full swing can easily reach temperatures of 60 to 70°C (140 to 168°F) at its center during the first few weeks. This heat is a sign that your microbes are working at full capacity. Bonus: this high temperature kills unwanted seeds and pathogens.
But here’s a secret that compost perfectionists don’t like to hear: your compost doesn’t need to heat up to 60°C (140°F) to work! “Cold” composting simply takes longer, but it eventually produces excellent results.
The Myth of the Slave Who Turns Their Compost
How many times have you heard that you absolutely must turn your compost every week, otherwise it’s guaranteed to fail? Let me free you from this chore! In nature, no one comes along with a pitchfork to turn over dead leaves, and yet they decompose very well on their own. The secret is to get the balance right from the start.
Yes, microorganisms need oxygen. But aeration can happen naturally with a good mix of structural materials. A few branches at the bottom of your composter, a good balance between wet and dry materials, and you’re free from the weekly chore! Personally, I layer my materials (a little green, a little brown) and only mess with it if I have a specific problem, such as an odor or excessive compaction. Keep a pile of twigs or leaves handy: they work well after a trip to the radish patch!
Guide de dépannage pour compost en détresse
Symptom 1: “My compost smells like a swamp of rotting skunk juice.”
Diagnosis: Too much moisture and not enough ventilation. Your poor bacteria are suffocating and anaerobic (oxygen-free) processes are taking over, creating sulfuric odors.
Laidback gardener’s solution: Add a good amount of dry brown material (dead leaves, shredded cardboard, wood chips). Aerate it a little: let air circulate between the layers.
Symptom 2: “Nothing has changed since the Ice Age.”
Diagnosis: Not enough nitrogen
to feed your microbes, or your compost is too dry. You also need a minimum volume of 50 to 70 cm (20 to 28 inches) high for the machine to start working.
Solution: Add fresh green matter (peelings, grass clippings) and a little water. Tip: a handful of garden soil will provide the missing bacteria to restart the process.
Symptom 3: “I have unwanted visitors.”
Diagnosis: Presence of fat, meat, or compost that is too wet, attracting flies and rodents.
Solution: Always cover your kitchen waste with brown materials, and avoid meat and dairy products in a home compost. A tightly fitting lid also helps, although I have never used one myself!
Take Advantage of the Start of Summer To Brush Up on Your Techniques: The Laidback Gardener’s Action Plan
With the arrival of warmer weather, your microbes come out of their winter slumber and become hyperactive again. You also have more green matter available with all those vegetables from the garden that need to be peeled and that grass clippings that need to be disposed of somewhere!
Step 1: Assess your current situation. Is your compost heating up? Does it smell good? Is there visible activity?
Step 2: Adjust the moisture content using the “hand test”: take a ball of compost in your hand. If it falls apart, it’s too dry. If juice runs out (yum!), it’s too wet.
Step 3: Store last fall’s dead leaves in a corner of your yard—they’ll come in handy all year long to balance out your green additions.
Summer maintenance: Keep feeding regularly, alternating between green and brown. That’s it. No stress, no strict schedule, just common sense!
The Little Secrets That Make All the Difference
The Rainwater Trick
If you need to water your compost, use rainwater rather than tap water. Chlorine in municipal water can harm your precious microbes. That’s why I don’t have a lid, by the way! It rains right into it. Still, make sure you have drainage and ventilation holes around the perimeter of your composter.
The Magic of Nettle Manure
A few sprinklings of diluted nettle manure can give a boost to laidback compost. Your bacteria love this natural nitrogen boost!
Early Season Tip
In early spring, a little turning can help to get the machine going again after the winter. But once it’s underway, let it happen!
And Here’s the Ultimate Secret
Composting is a natural process that has been going on for millions of years without our help. Our role is just to create the right conditions for our little devoted subjects… (sorry, microscopic workers), to be happy. That’s right: you’re not really a god because, let’s face it, these microbes were around long before we were!
The Three Golden Rules:
- Balance your materials (a little green, a little brown – never blue!).
- Watch the humidity (neither soggy nor dry like your old neighbor’s cookies).
- Be patient (laidback!) and stop trying to control everything!
Your compost doesn’t look like that of Instagram’s gardening influencers? Perfect! There’s no one way to make compost. The important thing is that it works for you, in your reality, with the time you have. And for them, well… they probably bought it for their video!
And if you’re still discouraged by your heap’s refusal to cooperate, remember that even me, who’s been studying these little beasts for years, sometimes has batches of recalcitrant composts. It’s only to be expected! We learn, we adjust, and we always end up with our precious black gold.
Tell me in the comments: what are your compost problems? I can’t wait to read your stories (and your creative solutions)!
Didn’t mention the best part of composting for the garden, worms! I will buy a bucket full occasionally and let them do their thing. They help break things down, and the castings (poop) is like gold.
I started using a tumbler last year. Currently it’s all clumped into balls of mud with the consistency of putty. I guess I’m going to have to get my hands in there to mix in more brown stuff?
You are going to have to add brown stuff, but you shouldn’t have to put your hands into the muck if you have a tumbler. Add brown, tumble periodically, until the putty dries and loosens. Good luck!
Timely article as we are about to create a new compost area. The old heap has been inundated with blackberry and other things. This time we have cleared an area down to the soil. I would love to read an article about the benefits of structures of different kinds versus just a pile!
Long ago a 3 bin design came out of one of the ag univrsities – long enough ago that I ahve not seen accribution. But plans are all over the place. I have used 2x4s, 1/2 inch screen, and cedar fence boards for my material. https://www.spokanecounty.gov/DocumentCenter/View/4867/Building-a-Three-Bin-Compost-Bin-PDF
Thank you for taking the mystery out of the composting process. I’d always avoided it, but now am encouraged to do it