How to Compost: Materials and Methods for Home Composting

Turning food scraps, yard trimmings, and other organic materials into nutritious compost is a great way to supercharge your garden’s soil while reducing your methane emissions. Composting isn’t as simple as it may seem, though. The composting process requires a bit of work, and it can take up to two years of feeding, watering, and aerating to produce usable compost. 

The good news is that you usually don’t need much equipment to get started. In fact, you don’t even need a tumbler or compost bin, though these products can help. There are several ways to compost, and some only require an out-of-the-way corner of your yard for a compost heap where materials can decompose. 

Keep reading our beginner’s guide to backyard composting to learn how you can turn your organic waste into what farmers call “black gold.”

Benefits of composting

Using homemade compost instead of chemical fertilizer for your garden bed, houseplants, or lawn is hugely beneficial for you and the environment. Enriching soil with organic compost ensures your plants get valuable nutrients like nitrogen and potassium, and compost-enhanced soil is also more conducive to healthy roots, ideal water absorbency, and good pH balance.

Meanwhile, long-term usage of chemical soil additives can cause soil degradation, nutrient deficiencies, and soil carbon shortages. 

In short, garden soil amended with organic compost instead of chemical additives produces hardier and healthier flowers, grass, trees, and vegetables in the long run.

Beyond your backyard, composting can also benefit the planet. Did you know that roughly a third of the food produced worldwide is wasted? This means all the water, soil, and labor used to raise that food was spent just to stick it into dwindling landfill space. Using uneaten food for a constructive end prevents these resources from going completely to waste.

Additionally, food waste sent to landfills produces a lot of methane. Microorganisms that make methane when they decompose food are only active in the absence of oxygen, so when food gets buried in a landfill, these microbes activate and churn out the harmful greenhouse gas during decomposition.

When you compost at home, on the other hand, you do it above the ground and aerate your compost pile. Uneaten food in a backyard compost pile decomposes while inundated with oxygen, the methane-producing microbes never activate, and the food breaks down methane-free. 

All of this combined makes composting your kitchen scraps instead of throwing them in the garbage can an excellent choice if you want a better harvest, prettier flowers, and a brighter future. 

What your compost needs

A handful of compost is cultivated with a good mixture of brown materials, green materials, water, and oxygen. Image source: Colorado State University

A healthy compost pile will be full of bacteria and fungi that digest the materials you add, turning them into usable compost. To ensure the decomposition process goes well, you have to make sure you feed these microbes the right stuff, so successful composting involves a surprising amount of chemistry. 

Here’s a quick breakdown of everything the microbes in your pile need to thrive. 

A dedicated space

First, you should pick a good spot for your compost pile. This can be a discreet corner of your backyard, a wooden bin by your shed, or a compost tumbler on your balcony. Whatever you choose, make sure it’s a spot you won’t need for other purposes. Remember: composting is a continuous process, and it can take up to two years to cultivate usable compost. 

When selecting a patch of earth or buying a bin for your compost, make sure you’re giving the pile three to five square feet of space. This will ensure the pile is large enough to start the chemical processes involved in decomposition and small enough to properly manage and aerate. 

If you need more compost than one space of this size can generate, make multiple compost heaps instead of one large one. 

Brown matter

Brown matter includes materials like dead leaves, newspaper, cardboard, and dry wood. These materials provide the carbon necessary to fuel the microbes living in your compost, so feeding your pile enough brown matter is crucial.

The correct amount of brown material isn’t a set weight. It’s a ratio. Generally, you want three times as much brown matter as green matter. So if you put three pounds of carbon-rich materials like shredded paper and old mulch into your compost, you’ll want to also add roughly one pound of green matter.

Green matter

Green matter is your compost’s source of nitrogen, an essential nutrient for healthy microbial growth. As a general rule, fresh plant materials that are still wet and green are considered green matter. However, the color isn’t what makes something a green material – it’s the nitrogen content. So this category also includes items like human hair, egg shells, and coffee grounds, all of which are rich in nitrogen.

As with brown matter, the correct amount of green matter for your compost will be determined by the three-to-one ratio. For every pound of yard trimmings, tea bags, and leftover veggies you add to your compost heap, you should also pile on three pounds of brown matter. 

And don’t worry. Basically, everything you add to your compost will have at least a little carbon AND nitrogen, so you don’t have to be overly precise in your measurements. 

A little bit of soil 

Soil is necessary to get the decomposition process started. The microbes you need for composting can be found in the dirt from your yard or garden, so throwing a couple of shovelfuls of this soil onto the pile will introduce all the microbes you need. As your pile decomposes and you put more material into it, these microbes will naturally propagate, but you can still add more dirt as you see fit. 

Plenty of air 

In addition to giving your compost microbes enough green and brown matter to eat, you should also make sure they have enough air to breathe. Most of the microbes in your pile are aerobic bacteria, meaning they use oxygen to oxidize carbon. If the microbes in the middle of the pile can’t breathe, it’ll slow down the process. A rotten egg odor emanating from your pile is a telltale sign of this. 

Regularly turn and mix your compost pile with a shovel or a pitchfork to guarantee enough oxygen is reaching all the microbes. The perfect frequency of turning will vary, but as a general rule, once a week should be sufficient. If your pile starts to smell bad or stops degrading material, try turning it more often. 

Water 

Water is the final ingredient of a healthy compost heap. Ideally, your pile should be about as damp as a wrung-out sponge. To maintain this dampness, you should ensure your heap has sufficient drainage and keep it near a source of water for convenient watering. In arid climates, you’ll have to add water to the heap more often than in humid regions. 

Materials you can and cannot compost

Keep in mind that these aren’t comprehensive lists. Most organic material (stuff that is or was once alive) can be composted. However, not all of it should be, and some materials can only be composted under special conditions. 

For example, nutritious items like grease, meat, and milk are compostable, but they can make your compost pile stink and they might attract scavenging rodents, raccoons, and insects into your yard. You should only compost items like these if you can manage the pests and your pile is far enough away from your house that the odor won’t matter. 

Similarly, you shouldn’t compost weeds unless you plan to hot compost (we’ll discuss that shortly). Otherwise, the weed seeds might start to grow and take root in your hard-earned compost.

Different composting methods

There are three typical home composting methods, and the right one for you will depend on several factors like how much space you have, how soon you need your finished compost, how much work you want to put into the process, and how much you dislike worms. 

That’s right. Worms. 

Hot composting

Hot composting, also called “active composting,” is the quickest and most effective way to make compost, but it also takes the most work. This method is called “hot” composting because the pile literally cooks itself as the materials decompose. 

This is because the microbes in the pile generate heat when they oxidize carbon in the brown matter. When billions of these microbes are all working under ideal conditions, the pile can heat to over 160°F, though you’ll want to keep it at about 140°F by turning it frequently and maintaining the correct amount of moisture. 

To create the right conditions for active composting, you have to regularly monitor the pile, feed it the perfect amount of brown and green matter, and turn it more than once a week.

All this work comes with a few key benefits. Active composting can give you usable compost in just a few months, and it allows you to compost weeds because the pile will actually cook the seeds before they can germinate. 

If you need your compost ASAP and you don’t mind putting in a little extra elbow grease to get it, then hot composting is the right method for you. 

Cold composting

This method is called “cold” composting because the microbes in a cold pile don’t thrive the same way they would in a hot pile, so they don’t generate enough heat to actually cook the compost during decomposition. 

Cold composting is far easier than hot composting because the two methods are basically the same, but you monitor and manage a cold pile a lot less actively than a hot pile. You don’t need to be as careful with the ratio of greens to browns, you don’t need to turn the pile as often, and you don’t need to monitor the pile’s temperature to ensure things are going well.

The main downside of cold composting is time. Since you aren’t putting in the work to maintain ideal decomposition conditions, it can take years for a cold pile to produce usable compost. You can keep adding materials to the pile that whole time, though. Just make sure you don’t add any weeds. 

If you’re just composting to divert food waste from the landfill and you don’t actually need the compost anytime soon, then cold composting is the right method for you. 

Vermicomposting 

Vermicomposting, or “worm composting,” is exactly what it sounds like: using live worms to digest waste and produce compost. Unlike the other two composting methods, this one requires a few upfront purchases before you can get started. First, you’ll need to buy or build a worm bin. Second, you’ll need to buy about a pound of earthworms. 

Not all earthworms are suitable for vermicomposting, though. Eisenia fetida, also known as “red wigglers,” are the best worms for the job. 

Once you have your bin and your worms, you’re ready to start vermicomposting. At this point, the process becomes basically the same as it is with the other composting methods. A three-to-one mixture of brown and green matter is still ideal, you’ll need some dirt, you should keep the composting pile damp, and you should regularly aerate the pile. Worms need air too!

Vermicomposting usually produces usable compost in a few months, and here’s where it might get gross for the faint of heart. Once your compost is ready to harvest, you’ll have to open up your bin and scoop out the finished compost without removing any worms from the bin. This will probably require you to touch the worms. A lot.

One of the key benefits of this method is that it takes up less space than composting in your yard since worm bins can be as small as 10 gallons. The bad news is that you’ll need to keep the bin inside your house. Leaving it outside would make the worms too vulnerable to outdoor weather and temperatures. 

If you don’t have a lot of space for a compost system and your stomach doesn’t turn at the sight (or feel) of worms, then this method is for you. 

How to tell when your compost is ready

Give your compost a few months to decompose and cultivate before you try to harvest it. If you’re cold composting, give it at least a year. 

Your compost is ready once it has a dark chocolatey color, it has a soil-y consistency that crumbles in your hand, and it has a rich earthy smell. If there are still some distinguishable food scraps or other materials in the finished compost, you can pick them out and put them back into the pile to start the process over.

Once your compost is ready, you can add it to the soil in your garden, your yard, or your potted houseplants to help them grow stronger and healthier. 

Is composting right for you?

Composting takes a little planning, time, and work, but anyone can do it. All you need is space for your compost pile and the right materials to feed it, most of which you’ll supply from your kitchen after meals or your yard after routine pruning and raking. As an added bonus, diverting this waste from landfills means you’ll be helping Mother Earth at the same time you’re helping your hydrangeas.