Composting doesn’t just happen at industrial facilities; it can be a revitalizing part of any home garden. And whether you’ve just started saving those onion skins from dinner or you’ve had a flourishing compost bin forever, speeding up decomposition in your compost pile is a game-changer for what you can grow in your garden or the amount you can contribute to your local farming project.
But it can be frustrating to change the pace of a natural process. Working with the science of how organic materials become soil, gardeners have figured out how to speed up composting with just a little extra dedication and attention.
What is Composting and Why is it Important?
A compost pile is a mixture of natural materials, mostly plant matter, that has decomposed together into a dark, crumbly material. It’s an especially dense amalgamation of organic matter that you can make yourself. Composting is that process, from getting all the organic material together to harvesting.
The majority of kitchen scraps and grass clippings we produce are compostable, so using them in the garden reduces the waste we send from commercial agriculture to landfills. Growing vegetables using soil from your compost pile begins to make a closed circuit for what you eat, and because of this, composting is an integral part of projects working towards zero-waste living.
But even if you’re not growing food, soil from a healthy compost pile supplies rich nutrients for flowers, decorative plants both indoors and out, and even greener lawns. Contrary to some myths, the decomposition squashes pests and weeds. Making compost with your neighbors on your block, in your building, or at your community garden can be a wonderful way to build lasting relationships. No wonder so many gardeners call compost piles “black gold!”
How Does the Composting Process Work?
First, organic matter breaks down as microorganisms from the air, the surrounding soil, and the brown material itself eat through it. There are two types of these microbes, and so two types of compost piles: aerobic and anaerobic.
Anaerobic means the microorganisms don’t require oxygen to live, so decomposition can occur in completely sealed containers. This way may result in fast composting, but it’s also smellier because the bacteria release methane and sulfur, making aerobic composting is more popular.
An aerobic composting system can be with open-air compost piles, compost bins, and ventilated drums. Many people build compost bins from pallets, barrels, or chicken wire, and most garden stores sell plastic tumblers. In aerobic composting, the microbes take in oxygen and release carbon dioxide and energy as heat, which further softens the material and serves as a good indicator of how much activity is going on in your compost pile.
The ecosystem of a compost pile functions best with a balance of materials often called “greens” and “browns.”
Green materials are fresh trimmings like fruit and vegetable rinds, kitchen scraps, and grass clippings. These things are rich in nitrogen, and compost bacteria need nitrogen to synthesize proteins. They need carbon to make energy, and great sources are found in brown material: dry, plant-based products like cardboard, dry leaves, egg cartons, and hay or straw.
Adding used coffee grounds to your compost boosts the nitrogen content; when the filter is also compostable, toss the whole thing in for a one-two punch. The ideal ratio for compost to break down fast is 25-30 parts carbon to 1 part nitrogen—so much, much less green material than brown.
You can also compost eggshells and paper printed with black ink—soy-based inks are ideal. One thing to avoid composting above all is meat since it attracts another category of microbes and bugs. Some people also refrain from composting dairy products for the same reason, but they decompose a little bit faster. Plastics, of course, will not compost—try a reusable bamboo straw instead.
How to Speed Up Composting: 4 Strategies for Faster Compost
Nature is certainly magical, but it doesn’t need to be mysterious! Introduced by Professor Robert D. Raabe of the University of California, Berkeley, the following tips comprise the “Berkeley Method,” which can make finished compost within 14 to 21 days. Seasoned gardeners agree that taken together or separately, these strategies should help accelerate your compost so it’s ready to use sooner.
1. Hot Composting: Some (Microbes) Like It Hot
Within aerobic composting, there are actually two more kinds of composting: hot composting and cold composting.
Cold composting leaves the natural composting process alone to work on an open-air compost pile, so it can take months.
Hot composting, on the other hand, ramps up the heat generated by microbes in the organic material. It encourages the growth of these natural compost activators and speeds up decomposition, and the heat also kills weeds.
How to Use the Hot Composting Method
You can cover your compost with a tarp or put it in a ventilated container to build heat—just be sure it isn’t totally sealed, so air can get in to avoid the stinky liquefaction of anaerobic composting. It can also help to pick your compost’s location carefully: put it somewhere that gets direct sunlight, especially if it’s in a black or dark container, and it will quickly absorb the sun’s warmth.
2. Pile On the Kitchen Waste!
Big mounds of compost retain heat better than smaller ones, so getting together large amounts of organic matter to start out can make your entire process faster. If you’re having a hard time finding that much green and brown, ask your neighbors, family, and friends for their kitchen scraps and grass clippings. Landscapers and households with a lot of yard work often need a way to dispose of their garden waste. Horse stables have horse manure to spare.
3. Chop It Into Small Amounts
The smaller the pieces are, the more surface area microbes will have to flourish on composted materials. You can contribute a compostable trash bag, but you’ll help it along with a few snips of your kitchen shears. Shred paper, prune down twigs and cut vegetable excess into bits for optimal hot composting. Large pieces of wood, for example, are hard to compost because they decompose slowly and attract mushrooms first, so avoid them unless you have access to a chipper.
4. Stir the Compost Heap
Classic compost layers green and brown like lasagna and leaves it to intermingle. But the microorganisms will have better access to oxygen if you turn the compost, stirring it once it’s warm to mix the parts and aerate. And when you add new material, don’t squash down the older compost to make room for the new, but fluff it all together. There’s no set rule on when to rotate your compost.
Turn it frequently when you notice changes, and don’t be afraid to do it too much. This, together with breaking up your materials makes hot composting the most labor-intensive method—but it’s also the most rewarding. Many composting bins come with built-in cranks to make rotation easier.
6 Tips and Tricks for Nutrient-Rich Compost
As you get to know your way around your compost, try these adjustments and add-ins.
- Dry materials stall the composting process, so sprinkle your compost with water to give microbes an accommodating environment. Avoid adding cooking oil, which can alter the moisture distribution.
- Give the whole process a jolt at the beginning by adding bacterial jumpstarters, also called compost activators. Some gardening stores sell dry, packaged microbes you can introduce into your biome, but home solutions like beer and rabbit food have also given great results.
- Monitor your compost with a thermometer designed for it, with a long needle. You can also use your hands to reach into the center of the pile, where the compost will be the warmest, the darkest, and the furthest along. Healthy hot compost will measure between 140 and 160 degrees Fahrenheit.
- Don’t wait to use your compost! Not everything decomposes at the same rate, so don’t hold out for those more fibrous bits. You can sift what’s ready from what’s not to use your compost sooner and get optimal nutrients.
- If you have access to horse manure, chicken manure, or animal bedding, toss it in! Dried refuse works best and it still contains good bacteria and the nutrients of what the horses, cows, or goats have been eating. You can also buy bone meal to enrich your compost and give use to a byproduct of the livestock industry.
- Send away for a worm colony, or find a few of the critters on the sidewalk and give them a home. Worms process and purify compost, digesting it into healthy soil.
As a Composter, You Are Part of the Solution
Whatever you decide to try, the best thing about compost is that it’s almost completely self-sustaining. The main thing you really need is a passion for natural living.
Download Our Free Guide to Sustainable Living.
From reducing waste to recycling and upcycling, our e-book shows simple ways to make choices you can feel good about.