What Is Compost and How to Use It

Compost is a crumbly, dark dirt so rich in nutrients that it’s used as mulch, fertilizer, or soil amendment but rarely to grow plants directly. 

You make compost from food scraps, garden trimmings, and other organic waste by letting beneficial bacteria decompose everything to its essential elements. It happens every day in nature, but when you make compost at home, you get to control and improve the process and the result.

Why is compost so beneficial for plants? What is compost made of? Can you really make it in your kitchen? These are just a few questions we’re answering in this article. When you finish reading, you’ll have all the information you need about “black gold” and the benefits it can bring to your lawn and garden. 

What is compost?

Also known as “black gold” or “garden gold,” compost is a crumbly, dark, humus-like dirt rich in organic matter and nutrients from decomposed food and yard waste. The process of decomposing this matter is called composting and uses beneficial soil organisms to convert organic materials into their basic components. 

Gardeners and lawn owners love using compost as mulch, topdressing, and soil amendment to support plant growth and improve crops. 

Homemade compost is easier to produce than most people think. You can compost outdoors, under a shade tree in your backyard, or indoors, placing a composting bin under the sink, on the balcony, or in the basement. 

It takes 3 weeks to a year to convert food scraps and yard trimmings into compost, depending on your method. 

“Why should I compost when I can buy ready-to-use fertilizers?” you might wonder. Composting is easy enough that anyone can do it, even with a black thumb. It’s all-natural, organic, and has incredible benefits for gardens, lawns, and the environment.

Top 7 benefits of homemade compost

Compost does wonders for soil, plants, and crops when put to good use. Here are its top seven benefits to convince you it’s time to start your own compost pile!   

1. Improves soil texture  

Compost adds an essential component to the soil that synthetic fertilizers lack: organic matter. Organic matter improves soil texture, increasing its water-holding capacity and helping plants cope with drought. 

According to the Department of Natural Resource Ecology and Management of Iowa State University, increasing the organic matter by 1% helps the soil hold up to 20,000 more gallons of water per acre. It can make a huge difference in water use, crop yields, and garden maintenance costs in states suffering from drought, like California, Utah, or Nevada.

2. Keeps soil microorganisms healthy 

Compost is rich in carbon that remains trapped in the soil for longer, feeding the beneficial microorganisms in your lawn and garden. A good example is earthworms that aerate and loosen the soil, improving drainage and limiting erosion. 

3. Supports healthier plants and prevents mineral deficits

Compared to synthetic fertilizers, compost is also rich in trace minerals. In addition to the primary nutrients found in commercial fertilizers (nitrogen, phosphorus, potassium), compost includes calcium, iron, magnesium, manganese, zinc, and other minerals plants need to grow healthy. 

For example, adding compost as topdressing to your lawn is an excellent way to prevent iron chlorosis. 

4. A natural way to balance pH for acidic and alkaline soil

It’s not uncommon for a soil test to show a pH imbalance that negatively impacts your turf, veggies, flowers, or trees. Changing soil pH with lime and sulfur can be challenging, and it’s usually better done by a pro. 

But with compost, you can’t go wrong. The organic matter it contains is a natural buffer that gradually changes pH from too low or too high toward neutral. It also prevents abrupt pH changes. All you have to do is amend the soil using matured compost.

5. Reduces food waste

Studies show the average American family of four throws away about $1,600 worth of food every year. Instead of throwing that money out the window, why not reinvest it into your lawn and garden? 

Remove kitchen scraps from the waste stream to obtain natural, organic homemade compost that works magic on grass, decorative plants (including indoor plants), and crops. 

6. Reduces waste disposal costs

Did you know that food and garden scraps comprise almost 30% of your annual waste? Now think about the monthly cart rates you’re paying for having it disposed of properly. Wouldn’t it be nice to save some? 

Put aside your fruit cores, peelings, veggie scraps, and old produce, and turn them into a natural fertilizer for your vegetable garden or potted plants. Reduce the amount of waste you produce and your waste disposal costs. 

7. Actively reduces methane emissions in landfills

Food and yard scraps that get into landfills are usually covered with tons of other waste and decompose anaerobically (without air). The anaerobic decomposition process releases biogas which is 50% methane and 50% carbon dioxide, a potent greenhouse gas that adds to climate change even as you read this. 

Currently, landfills in the U.S. are the country’s third most significant source of methane emissions, and we are feeding them relentlessly, month by month, with raw materials. 

Home composting is mainly done aerobically (in the presence of air), with low methane emissions. Stopping organic waste from reaching landfills and composting is an excellent way to protect the environment – all while also enjoying tastier, juicier fruits and vegetables from your garden, a greener lawn, and more blossoms on your flowers!

Types of home composting

There’s more than one way to make compost. Whether you own a large property in the green lands of Montana or watch the sunset from a small condo in Los Angeles, there’s a way to make good-quality compost in your space. Let’s look at the most popular composting methods and what they offer.

Hot composting vs. cold composting

As the name suggests, hot composting uses heat to decompose organic matter faster and more thoroughly. This method requires high temperatures up to 140 – 160°F, forming in the center of the compost pile. It’s the high heat that allows fast decomposition and also kills pathogens and weed seeds. 

To heat your compost, you must control the carbon-to-nitrogen ratio, moisture, and oxygen level – aerobic bacteria drive the hot decomposition process. 

Hot composting is a suitable method if you’re willing to invest time in managing the bin and need safe compost fast. You’ll need to turn the pile weekly, keep an eye on the moisture level, and insulate the bin if it’s cold outside. Hot composting can be done indoors and outdoors.

On the other hand, cold composting is less demanding and slower. In this case, you just layer the compost pile and let it be until next year. Decomposition is first aerobic, and the mix heats up a bit. Then the oxygen runs out, and anaerobic bacteria take over. 

It’s a good option if you’re not rushing to use your compost in your garden, lawn, or potted plants. Cold composting doesn’t kill pathogens and weeds, so you’ll need to be extra careful about what you add to the pile. It’s also smelly and not suitable for composting indoors.

Vermicomposting

Also called live composting, vermicomposting is a popular method that uses worms to decompose waste. It is a fast and comfortable way to recycle food scraps, especially if you intend to install a composting bin indoors. Vermicomposting is odorless, and the worm bins are typically small and easy to place under the kitchen sink, on your balcony, or in the basement.

Enzymes inside red worms decompose the organic matter. Worms eat food waste and excrete nutrient-rich compost, also called worm compost, vermicompost, or worm castings. The process also has a byproduct called worm leachate, a liquid draining from the bin during composting that can be used as fertilizer diluted in water with a ratio of 1:100.

Where to shop red wigglers for vermicomposting online:

Uncle Jim’s Worm Farm – Red Wiggler Live Composting Worms Mix for Garden Soil – Amazon
Arcadia Garden – Worm Nerd Live Composting Worm Mix (100 Worms) – Home Depot

Bokashi “composting”

While very popular among apartment dwellers looking to obtain organic fertilizers from their food scraps, the Bokashi method is not an actual composting method. Food scraps are not decomposed but fermented by anaerobic microorganisms. Fermentation is sped up by adding an activating solution called Bokashi bran. 

The final product takes two weeks of fermenting and is a pre-compost. Add it to the garden soil a few weeks before planting so it has time to break down more or put it in your outdoor compost bin.  

The Bokashi method is an excellent solution to make food like eggs, dairy, and meat easier to compost. During fermentation, it also produces a liquid known as compost tea or Bokashi tea.  It’s an excellent fertilizer diluted with water at a ratio of 1:100.

Bokashi kits are available online on Amazon, Walmart, and other retail and home & garden shops.

Indoor, outdoor, and community composting

You can build a compost pile or bin in your backyard, compost in a closed container in your apartment, or take the waste to a community composting site. 

Indoor composting is an excellent way of reducing home waste and making high-quality, free fertilizer from your kitchen scraps for your potted plants. Since it all happens in a closed environment, choose a method that doesn’t produce unpleasant odors. The most popular are vermicomposting and Bokashi composting.

Indoor composters are small, fit for food waste, and less suitable for yard trimmings like twigs and branches. 

Outdoor or backyard composting is the most commonly used and the most comfortable if you have a yard with enough space. You can use closed or open bins or bury the raw materials directly in the soil. This method uses a variety of sizes and types of bins, and it’s the best way to compost garden waste. 

Community-scale composting programs are managed privately or by the municipality and offer the possibility of sending or taking the waste to a common site for controlled decomposition. 

It’s a smart way to recycle waste if you don’t have enough space for a composter at home. Here’s a map with community composters around the U.S. you can use to find waste composting programs in your area.

Does compost always need a bin, and what’s the best type? 

Composting doesn’t always require a bin, but containers, DIY or bought at the store, can help make the process faster and easier. They also make indoor composting possible. Here are the most common types of bins and a popular alternative method for those who can’t or don’t want to use a container. 

Open bins: the best for composting yard waste 

The open-bin composting method doesn’t offer much protection from the environment. This is mainly the case of compost piles in enclosures made of chicken wire, metal stakes, or wooden pallets. 

Open bins are also called “open-topped bins” or “open compost systems” and work best for composting yard waste. They are easy to build and cheap, even in large sizes. 

Pros of open bins:

• Easy to build and maintain.
• Cheaper than other options.
• Better aerated.
• Excessive moisture is rarely a problem.
• Excellent for garden waste, especially large branches. 

Cons of open bins:

• Offers no protection against dry air or moisture. In arid areas, you’ll need to water the mix more often.
• It exposes the compost to heat and cold. If the pile is too small in winter, reaching proper central heat is challenging. During summer, it might get too hot and kill the bacteria. 
• Various insects might infest the compost.
• More vulnerable to rodents and other pests that want to eat your food waste. 

Where to buy open bins online:

MTB – Garden Wire Compost Bin 36x36x30 inches – Amazon
Greenes Fence – 309.17 Gal. Cedar Wood Stationary Composter – Home Depot
Greenes Fence – 309.17 gal. Beige Wood and Cedar Multi-Stage Composting Bin – Walmart

Closed bins: the best for composting food waste

Closed bins look mainly like boxes made of plastic or wood. Most are bottomless, allowing the organic matter to sit directly on the soil. Beneficial organisms can help with decomposition while the compost liquids drain out, preventing soaking. Some models have a bottom with drainage holes

The top or front side is removable to add more compost materials and turn the contents. As for the walls, they have small holes to allow proper aeration. 

A particular type of closed bin is the worm bin, made to house red worms. It has more ventilation holes in the lid and bin and a second container with a cooler drain plug to collect the compost juice. 

Pros:

• Better protection from pests and the environment. 
• The pile heats up easier. 
• Keeps moisture in. 
• Easier to insulate during winter. 
• Safer for composting kitchen waste. 

Cons:

• More expensive to buy or build. 
• Limits air flow and might require turning more often. 
• It’s easier for the compost to become too wet or compacted. 

You can make closed compost bins DIY from plastic storage bins, wine crates, garbage cans, wood pallets, old wooden dresser drawers, and other similar containers you have around the house. 

They are also available in online shops like Amazon, Home Depot, and Walmart. Here’s a detailed guide to help you choose the best compost bin for your needs and budget.

Tumbler bin: speeds up composting and is easier to use

Tumbler bins are more work to build, but they’re worth it. You won’t need to remove the compost from the bin and turn the pile with a pitchfork or garden fork to aerate it. All you need to do is roll the bin twice a week, and the materials inside get enough ventilation and mixing. 

Tumbler bins look like plastic barrels built on a metallic axle or base that allows you to rotate the bin with a handle. Depending on the size, a tumbler bin can be installed in the yard, garage, or on the porch.

Pros:

• Easier to use.
• Simplifies mixing and aerating the compost.
• It’s sealed well enough to keep moisture in but also has holes that allow proper airflow.
• Speeds up decomposition. The average time of converting raw material into compost (without maturation) with a tumbler bin ranges from 3 weeks to 2 months.

Cons:

• More work to build DIY.
• Most models are more expensive than open and closed bins with similar capacity.
• Not so good when it comes to saving space in your garden. Tumbler bins usually offer half the capacity for the same footprint because there’s a lot of free space underneath the container.

Tumbler bins are widely available online. You can buy popular models from shops like:

FCMP Outdoor – IM4000 Dual Chamber Tumbling Composter – Amazon
RSI – 65 Gal. Two-Stage Compost Tumbler with Cart – Home Depot
SuperDeal – 43Gal Compost Bin Dual-Chamber Tumbling Fertilizer Tank – Walmart

Trench composting: a low-maintenance, no-bin solution

With trench composting, you practically dig a hole and bury the organic waste into the soil. Cover it with a layer of dirt 12 to 18 inches thick to hold moisture and protect composting materials from pests. Then you just let it decompose. Trench composting can be used to enrich the soil in extensive gardens by creating trenches between vegetable rows.

Pros:

• It’s the easiest and most low-maintenance composting method. 
• Doesn’t require aeration or turning the organic materials.
• You can add dairy or animal waste if you cover it with a thick soil layer. 
• It’s invisible and does not impact your garden’s design.
• It helps nearby plants by constantly leaching small amounts of liquid fertilizer.

Cons:

• You can’t add more waste over it once you cover the trench with soil.
• Slow decomposition. It mimics the natural process the most, taking about a year until the compost is ready.
• It’s hard to remove compost after decomposition to use it elsewhere. Trench composting is typically used to enrich the soil in the place of installation. 

Essential compost ingredients

To make high-quality compost, you need four essential ingredients: carbon, nitrogen, water, and air. 

Carbon

Carbon-rich materials added in compost are also called “brown waste,” “brown materials,” or “browns.” The most commonly used brown materials are:

• Dry leaves 
• Plant stalks, twigs, and branches
• Wood chips (untreated)
• Sawdust and wood ash (sprinkle in thin layers to avoid clumping)
• Brown paper bags (shredded)
• Not-glossy, not-colored paper (shredded)
• Cardboard (without waxy layer, glue, or tape; shredded)
• Straw and hay
• Tree bark
• Dryer lint with only natural fiber
• Pine needles
• Pinecones
• Paper napkins

Browns are the dry part of the compost, and their primary role is to feed the decomposing microorganisms.

Nitrogen

Nitrogen-rich materials are called “green waste,” “green materials,” or just “greens.” Common compost greens include:

• Fruit and vegetable scraps
• Crushed eggshells
• Grass clippings (cut in smaller pieces and spread in thin layers to avoid clumping and matting)
• Yard trimmings
• Used coffee grounds
• Paper coffee filters (if vermicomposting, don’t add bleached filters, as they can be toxic for compost worms)
• Biodegradable paper tea bags (except the staples)
• Chicken, pig, cow manure
• Hair or pet fur
• Seaweed

Greens are the wet part of the compost and have a massive role in heating the pile and ensuring effective decomposition. Nitrogen is essential to aerobic bacteria growth and reproduction. 

Oxygen and aeration

The microbes decomposing the compost materials need air to live and thrive. With proper aeration, they multiply and work faster. If not, their number decreases, and composting takes longer.

Experts recommend turning your compost at least once a week during summer (ideally once every three or four days) and every three to four weeks during the winter. Try the Berkeley or rapid composting method to speed up decomposition: turn the pile every other day. It should be ready in under three weeks compared to 3 to 5 months using the traditional way.

Water and keeping moisture constant

Microorganisms also need a moist environment to survive and move around. The ideal compost is damp, like a wrung-out sponge, with 40 to 50% water. Overly dry or soaked compost decomposes slower or stops altogether. 

The best test for checking the moisture level is to take some compost in your hand and squeeze. The moisture level is perfect if one drop of water starts to form or falls. 

Most of the time, the greens are wet enough to ensure proper moisturizing. If the compost feels dry, spray some water when layering and turning the material for aeration. When the compost is too wet, add dry materials like cardboard or dry leaves and turn the pile. 

The best carbon-to-nitrogen ratio in compost and how to achieve it

The carbon-to-nitrogen ratio, also known as the C:N ratio, is debated in many scientific papers. Most studies indicate that a 25:1 – 30:1 ratio is the level that makes decomposing bacteria the happiest and most comfortable in a compost pile.

Browns and greens have different carbon-to-nitrogen ratios. For example, twigs have a 500:1 ratio and shredded cardboard 350:1. In contrast, vegetable waste has an 11:1 ratio and chicken manure 6:1. To get the desired level of 25:1 – 30:1, we mix browns and greens in different amounts. 

Don’t worry. Few people actually calculate how much carbon and nitrogen each type of waste brings to the mix. In practice, we use a long-tested rule of thumb to add 2 to 4 buckets of brown materials for each bucket of greens.

What to keep away from your compost bin

Compost is a valuable resource for homeowners invested in organic gardening or eco-friendly lawn care. This is why garden waste contaminated with pesticides, herbicides, synthetic fertilizers, and other chemicals is usually left out.

Another thing to avoid is scraps that decompose slower and give a strong odor when breaking down, attracting rodents and other pests, such as eggs, meat, bones, and dairy products.

Here’s a list of common organic products you should AVOID adding to a compost bin:

• Dairy products
• Eggs
• Meat scraps and bones (including fish bones)
• Fat, oils, grease, lard
• Pet feces and litter
• Coal or charcoal ash
• Yard trimmings treated with pesticides
• Any part of the black walnut tree
• Diseased plants or plants with signs of pest infestation
• Colored and/or glossy cardboard or paper
• Garlic and onion are acidic and can harm the microbes in your compost in high amounts (they also come with a pungent smell). 
• Citrus waste (acidic, harmful in large amounts)
• Dryer lint (not suitable for compost if it includes synthetic fiber)
• Any inorganic materials (plastic, metal, etc.)

6 steps to make high-quality compost in your backyard

With so much information,  making compost can seem like a complicated project. But once you start laying down what you need to do, it all comes down to six basic steps.

Step 1: Decide how and where to collect food scraps and yard waste

Kitchen waste: Most people place a container under the sink, on the counter, near a kitchen cabinet, or in the freezer. The idea is to make it easy for you and your family to place food scraps every time you cook or your kids munch on an apple or a carrot.

Yard waste: Set a place outside to collect branches, twigs, grass clippings, fallen leaves, etc. Cut them into smaller pieces and add them to the compost bin immediately. Such piles should be kept from standing too long since they can attract pests. 

Step 2: Select a place for the compost bin or pile

Decide how big you want the pile or bin to be and choose an appropriate space. Most outdoor piles are 3 by 3 feet to 5 by 5 feet. Smaller containers need help keeping the proper temperature inside the compost when it’s cold outside. Larger piles take a lot of work to turn and aerate. 

Pick a location with good drainage, a water source nearby, and preferably, not against a wood fence that might decompose with the pile.

Buy or make a compost bin to fit the space. Here’s a useful DIY tutorial for building a compost bin if you’re thinking about making your own custom bin.

Step 3: Prepare the ingredients

Cutting the ingredients into small pieces, about a thumb’s size, helps the bacteria decompose the scraps faster. Make a habit of cutting food scraps into pieces before adding them to the collecting container. Once they spoil, this part becomes less pleasant.

Use a mulching mower to cut grass clippings small when trimming the lawn. A lawn mower is also helpful for cutting fallen leaves into tiny pieces.

Step 4: Build the compost pile

Start by spreading a layer of wood chips and twigs about 4 to 6 inches thick. Its role is to absorb the liquids leaching from the compost and also to help with aeration at the base of the pile. 

Continue by layering greens and browns. Spread some water if the mix seems dry. It should look and feel like a wrung-out sponge.

Finish the compost mix with a layer of browns. Make it 4 to 8 inches thick to keep pests away. Close the lid or cover an open bin with cardboard to limit rainwater access. 

Step 5: Maintain the compost

Keep the composting pile moderately moist and aerated to decompose fast and thoroughly. 

Use a pitchfork or garden fork to turn it once a week during the summer and every three to four weeks during the colder months. 

If it looks too dry, spread some water and turn the compost to ensure moisture gets everywhere and that there’s enough oxygen to sustain decomposition. 

When the compost pile becomes smelly, it usually has too much water. To reduce moisture, add some more brown materials and turn the pile to spread them around. 

Step 6: Let the compost mature

When the compost starts to cool down, and you notice very few scraps while mixing (mostly woody materials that are harder to break down), the decomposition stage is almost finished. But the mix still needs to sit for at least a month.

During this month of maturation:

• Compost becomes finer.
• Organic acids present during decomposition breakdown and compost pH rises from about 5.5 to values closer to neutral, usually between 6 and 8, making it more suitable for plants.
• Decomposing bacteria and fungi decrease in numbers. When you use cured compost, they’ll still be present to enrich the soil but not so much as to compete with your plants for nutrients.
• Any phytotoxic substances (ammonia, salts, organic acids) are eliminated.

Finished compost and how to test it

Finished compost is matured or cured compost, left to sit after the decomposing process ends. Some gardeners keep it in the bin, others put it in bags after it has cooled down. 

How do you know the compost is stable and ready to use? Here are a few simple tests:

• Measure the temperature in the pile’s center. It should be close to the air temperature.
• Smell the compost. Matured compost smells nice, neutral, and fresh, like forest dirt.
• Take some compost in your hand. It should have a fine texture without identifiable pieces.
• Measure its pH. Finished compost has a pH of 6 to 8.
• Put some compost in a pot and seed tomatoes, barley, or radishes. If they germinate, the compost is ready for use.

How to use compost

You can use the finished compost in numerous ways. Here are the most common four uses compost is praised for.

Soil amendment 

Most homeowners use compost to amend their garden topsoil and get richer, tastier crops and healthier plants. With commercially available topsoil costing $10 to $50 per cubic yard, this free, natural option is a magical source.

How to use compost to amend soil:

• Spread a layer of compost 2 to 4 inches thick. 
• Till it into the top of the soil 6 to 9 inches deep.  

Mulch

Compost is an excellent type of free mulch to use on vegetable and flower beds and when installing a new lawn. Once applied, it gradually releases nutrients, feeding the plants more with each watering. The compost layer also protects soil moisture and moderates temperature.

How to use compost as mulch:

• Loosen the top 2-3 inches of soil with a rake. 
• Add a 2-3 inch thick layer of compost mulch on top of the soil. 

Top dressing

Are you planning to seed or reseed your lawn? Use compost as a top dressing to give the grass seeds some nutritious cover and ensure good soil contact. 

How to use compost as top dressing:

• Spread a layer of compost ½ to 1 inch thick before spreading seeds.
• Work the compost into the top 1-2 inches of soil. 
• Water lightly.

Potting soil

Compost makes an excellent potting mix combined with garden soil. Rich in nutrients and organic matter, it is perfect for indoor and outdoor plants that require fertile soil with good drainage. 

How to use compost in potting soil:

• Mix 20 to 30% compost with 70 to 80% garden soil.   
• Store in a closed plastic bag in a dry, cool place. 
• Use whenever you get new potted plants or when changing the potting soil in old plants. 

FAQ about compost

Enjoy the benefits of natural, free, homemade compost!

Now you know what compost is and how it can transform the way you do gardening and lawn care. Still hesitant about starting your own compost pile? Lawn Love is here to help with the best experts at hand! Contact a local lawn care professional specializing in organic soil amendments and enjoy the benefits of natural, free, homemade compost!

Main Photo Credit: svetikd | Canva Pro | License

Lawn Love participates in the Amazon Services LLC Associates Program and other retailer affiliate programs. Lawn Love may earn revenue from products promoted in this article.