How to Compost: Filling & Maintaining a Compost Bin

by | May 22, 2020

Welcome to the 3rd article in our composting series! While Sam and I are new to hot composting, we are not new to composting in general. Many of you have asked me about problems with your compost—it doesn’t breakdown, it smells bad, or you have had issues with animals. Well, I decided it’s a good time to write that composting 101 article just to give you a good idea of how we compost and the basic principles we practice. PS: our next installment of the compost series will be a step by step guide to hot composting!

A Little Compost 101…

Before we discuss how to fill and maintain a compost bin, let’s talk about what compost is and why we want it. Compost is the decomposition of organic materials. In nature, all the fallen leaves, branches, worms, rain, and organisms create compost on their own. It is a natural process that would happen even without us humans.

Compost is a way to reduce the amount of waste that ends up in landfills AND it closes the loop between our food and our gardens. Finished compost is a garden amendment that will improve the texture and quality of your soil while providing all the nutrients your plants need. 

Gardening and composting are intertwined. If you love to garden and want to grow the most vigorous, productive, and healthy plants, you will eventually find yourself learning how to compost. As you yearn to cherish each and every piece of food you grow, you’ll realize you don’t have to let go of bits and pieces in the trash. The garden wants to feed itself. Are you ready to start composting?

What will you be doing exactly? Composting involves mixing the “ingredients”—brown/green scraps, water, and air—together in a one place and letting them breakdown into what looks like dark brown soil. That’s it!

This is our compost tumbler. It is a fantastic option for urban gardeners and for learning how to compost.

Types of Composting You Can Do

As I’ve mentioned before, there are many ways to compost. It is always best to assess your personal garden situation and space before deciding how you would like to compost. I always emphasize that composting doesn’t have to be labor or time intensive. You can always add your organic materials over time and let them decompose at their leisure. Here are some different types of composting:

♦Hot Composting: this is what we are practicing currently. Hot composting is labor intensive and requires monitoring of your bin’s temperature to figure out when to turn it. Hot composting also requires a certain volume of organic material in order to reach such high temperatures.

♦Tumbler Composting: We also do this! We’ve used a compost tumbler for years and think it is a wonderful option for small, urban spaces. It’s relatively critter and smell free! Check out my article on Compost Tumbler Basics for details and tips!

♦Vermicomposting: using worms to breakdown your organic materials! Worm bins are extremely popular, and for good reason! When worms eat your organic materials, they create “worm castings.” These castings are one of the best garden fertilizers out there! If you’d like to explore worm bins and view tutorials, check out this link to the Master Gardener’s vermicomposting resources. NOTE: the worm bin listed below is one we used to have, but we no longer vermicompost (an article is coming on that soon). The method of maintaining a worm bin will also vary slightly from what I describe in this article.

♦Direct Composting: Sometimes gardeners bury bins directly in the garden that have holes in the sides. You can place your compost scraps in these bins and worms are free to assist in the breakdown and distribution of the nutrients. See below for an example I found on Amazon or look for some DIY projects online.

♦Cold Composting: let nature take its course! This method still requires you to mix organic materials—your browns and greens—but instead of worrying about temperature and turning your pile, you can simply leave it to decompose naturally. You can also choose to turn it whenever you have the time. Eventually, everything will breakdown, although this method may take longer than the other methods described.

♦Bokashi Composting: this method of composting is very different! Bokashi composting is actually a process of fermenting as opposed to decomposition. It relies on grains inoculated with microbes to help turn your food scraps into a garden amendment. I have never tried this method before, but the kit below claims that this method of composting can actually be done indoors!

Our DIY wood pallet compost bin was new to the garden this year because we really wanted to challenge ourselves to generate more compost. This is how we learned how to hot compost.

The Elements of Decomposition

Before I get into the nitty gritty of how to compost and what to add to a compost bin, let’s take a look at the necessary elements that are required in order for decomposition to happen—and thus compost!

Air/oxygen – Air is needed for the microbes to survive and thrive in your compost bin. Air can be added through holes in the sides of your composter, or by turning the pile. I feel that turning the pile makes the biggest impact in getting that air where it is needed throughout the pile. Aeration can also help keep your pile from developing an odor.

♦Water/moisture – Just like our plants, compost needs water too, but not nearly as much. The microorganisms in the pile need water to break down garden scraps and reproduce. Most of the water for your compost will come from the scraps you add, but occasionally you will need to add water.

♦Organic matterThere are two categories: “Greens”(Nitrogen) and “Browns”(Carbon). Each category is discussed in detail below, but we are talking about all those kitchen scraps, shredded paper, plant material, etc.

DO NOT compost…

Do not compost dairy, meat, dog/cat poop, cooked food, any plants with diseases.

Never compost plants treated with pesticides or animal manure from animals treated with antibiotics/medicine.

Weeds should be avoided unless you are hot composting to a temperature where all weed seeds would be killed. This typically happens over 140 degrees F or more.

What is green matter for your compost bin?

As I mentioned above, one of the necessary ingredients for composting is green organic matter. Green matter is going to be the nitrogen in the compost bin.

Here are some things that are ideas for compost “greens”: 

Grass clippings- an extremely effective green that decomposes very fast. Grass really heats up our compost pile. We have small areas of grass around our home, so whenever we mow the lawn, we simply add the greens to the compost bin.

Kitchen veggie  and fruit scraps– As you are prepping dinner, set aside those peels, vegetables ends, stems, and hole-ridden leaves for your compost bin.

Garden “trash”: When you pull up expired or bolted crops in the garden, these are perfect additions to your compost. I frequently prune my plants and put all prunings in the compost bin.

Expired floral arrangements: flowers that have lived their full vase-life can be added to your compost bin!

Coffee grounds: did you know these are considered nitrogen inputs? Although the color is brown, they are actually a compost green! *NOTE: we used to have a filter-free coffee maker, but since it broke we have been using an old one. We found these compostable coffee filters and I’ve noticed they break down great in our compost pile. Coffee filters are a brown input!

Citrus peels: You may have heard that citrus can be too acidic for compost piles. Well, I’m in the camp that it doesn’t matter unless you are adding TONS of citrus. That being said, we don’t generate tons of citrus waste because I use most of what we grow, including the peels. Check out 15 Ways We Use & Preserve Citrus.

Eggshells: these are considered a green input. I have some special notes on eggshells for composting. First, wash out the shells after cracking. This eliminates some of the chance that your compost will smell like rotten eggs. Second, you can opt to leave your eggshells out of the compost and save them to dry and grind as a garden amendment.

Chicken/quail manure *see section below for safety guidelines

What about chicken or quail droppings?

There is a wonderful article from the WI Master Gardeners that covers the benefits, drawbacks, and safety concerns of using animal manure in the garden. You can read that article HERE.  In general, I would feel safest only using animal manure that has been composted at temperatures over 145 degrees F where possible pathogens could be killed. It is never advised to use manure from animals that are being treated with medicine or antibiotics or to use animal manure fresh in the garden. If you are composting on a patio, small space, indoors, or cold composting, I would not add manure. This is just a personal preference from an urban perspective. Eliminating smell is one of your best defenses against attracting animals to your yard or having problems with your neighbors.

Here are some examples of brown inputs and green inputs for composting.

What is Brown Matter for a Compost Bin?

Brown matter is the carbon input. For many gardeners, the most common brown matter are dead leaves—-this is especially the case in areas of the country where there are lots of trees that lose their leaves. For us urban gardeners, dead leaves and brown matter can be hard to come by.

Here are some things that are ideas for compost “browns”: 

Dead leaves: while rare around our home, we do occasionally get leaves that fall off trees and I add them to the compost bin.

Cardboard: tear off any stickers, tape, and labels until your box is plain cardboard. At this point, you can tear up your box and add it to compost. *NOTE: if the cardboard is thick, I will sometimes let mine soak in water so it is easier to tear apart into smaller pieces. One time, I left my cardboard out in the rain and it was very easy to tear the next day!

Toilet Paper rolls

Plain text mailings: avoid any glossy papers or lots of dyes. These days, most ink is non-toxic, but I still am pretty conservative about what I add.

Wood/wood chips: don’t add sawdust from wood treated with chemicals or trees treated with pesticides.


Pine needles

Coconut shells: these take forever to breakdown! I actually had to go through my mostly finished compost and move all my coconut shells to the next batch because they were breaking down so slowly.

This is the inside of our compost tumbler. We like to pre-process our food scraps in the tumbler before adding them to our compost bins to prevent attracting critters.

How to Fill Your Compost Bin

My preferred ratio of brown to greens is 1:1. Basically, just add equal amounts of both your brown material and green material. To make it easier to visualize, you can add your organic material in layers. Start with a layer of browns, then add an equal layer of greens.

Make several layers and add some water. Not a lot of water, but just get the top layer wet.

Next, I mix my materials at this point. Why? because I think it breaks down better when it is all mixed…..adding in layers just helps to visualize the amounts/ratio of browns to greens better.

You can continue this process until your bin is full. If you don’t have enough materials to fill your bin, that’s okay too. Just keep adding over time, remembering to have equal parts brown to green and keeping it moist.’

Covering Your Compost

Moisture is necessary for decomposition to happen. Some areas of the country get enough rain to keep compost moist without needing a cover, but for us, covering a compost pile actually serves two purposes:

1) covering your pile keeps animals out. You might notice that our DIY urban pallet compost bin  has a cover. We haven’t had any issues with critters.

2) covering your pile prevents evaporation of valuable moisture. In our hot and dry climate, we do not get enough rainfall or natural moisture to maintain a pile.

If you have a manufactured compost bin, they usually come with a cover/top. If you are going with just a compost pile, many gardeners simply use a tarp like this one to keep it covered.

Here are the layers of our compost pile before we mix it in. It shows the 50-50 ratio of greens to browns that we use for hot composting.

How to maintain your compost bin

Maintaining a compost bin can be as intensive or hands-off as you would like. If left on its own, a compost pile will eventually decompose—that’s nature! If you are vermicomposting, the maintenance is different since you are caring for living creatures! 

♦Option 1: Just leave your pile alone to decompose. Depending on the size and materials, this could take many months. It’s really hard to predict!

♦Option 2: turn your pile whenever you get the chance. Is your compost on an allotment or community garden? Maybe you only get to visit once a month? Simply use a garden fork to turn and check on your pile’s moisture levels when you can. This type of composting, again, will take time and can’t really be predicted.

♦Option 3: Actively turn your pile to keep it hot and breaking down fast! This is called” hot composting.” We turn our pile every few days, based on temperature readings. “Turning a pile” technically means just mixing the pile to aerate and re-distribute the organisms to keep them active. Hot composting is more labor intensive, but it can provide you with amazing garden compost in as little as two months! Check out our Hot Composting: A Step By Step Guide (Coming Soon)!

NOTE: moisture will need to be monitored throughout the process, and a balance of equal parts green and brown materials will need to be maintained. The main variable is how often you turn your pile.

Turning the Compost with a Garden Fork

My favorite tools for composting

While each gardener might have a different situation for their compost pile, there are some tools that I have personally found to be super useful for my backyard compost bin:

1) Garden Fork– I love this tool for turning a compost pile. In fact, I actually use a garden fork for a lot of tasks just in the yard. Forks are great for loosening up soil when pulling onions, garlic, or leeks.

2) Thermometer– in a hot composting situation, we determine when to turn our compost pile by assessing the temperature. It’s pretty cool to see a compost pile heat up to 165 Degrees F! This is the thermometer we use.

3) Tarp– Sometimes a tarp comes in handy. Not only can you use it to cover a pile if you’d like, but we also use our tarp during the turning process. We shovel out all our compost onto a tarp, and then shovel it back into the bin. This helps ensure that all the material is mixed together well and can keep the ground more clean. A tarp can also be used to lay on the ground when sifting your compost.

Compost FAQs

Below, I want to address some of the most common questions I get from gardeners who are learning how to compost.

Do I constantly add new material to an established pile?

This is a common question. You can continue to add new materials until your container or bin is full, but you will need to eventually stop adding material. Once you stop adding new material, your compost will be “finished” once that newer material has finally decomposed completely.

In the meantime, you can actually collect your green materials in a bag in the freezer and just set your brown materials aside in the garage/shed/closet/etc. If you are like us and have a compost tumbler too, you can actually use your compost tumbler for processing new materials while your compost bins are finishing the compost.

Do I need to chop all my greens & browns into small pieces?

This is all a balance. Smaller pieces will break down more quickly since more surface area is exposed BUT I personally feel that having varying sizes in a large compost pile can actually be most effective. Why? Leaving some larger pieces, or maintaining many pieces of different sizes, allows for better aeration of the pile which can help spur the decomposition process. If all your pieces are teen tiny, they can end up matting together and depriving that area of oxygen—-remember, air is an important element of the decomposition process.

In general, for tumbler composting or cold composting, smaller pieces do perform better. I have just observed that in our hot compost pile, the larger pieces really help the pile get very hot.

Want some advice for how to chop up your browns and greens? For the food scraps, we just use a kitchen knife and cut things up as we cook. I use large pruners for a lot of our garden scraps and fruit tree branches. Recently, we bought a cheap wood chipper and think it is fantastic. I love being able to break our branches into wood chips for both the compost and the mulch. We bought this chipper/shredder.

We like to tear or shred most of our compost materials. If cardboard is hard to tear, simply soak it in some water to soften it.

Do I need to sift my compost before using?

Sifting can be a good idea, but is not always needed. In fact, it’s more about personal preference. We like to sift to separate any large pieces that did not break down all the way, like our coconut shells for example. We take these larger pieces and put them in our new pile and give them another chance to break down.

Sifting can be made easier with a bucket sifter like the one pictured below. A 1/2″ mesh is large enough to not clog to easily, but still catch the large chunks.

What are some urban friendly compost ideas?

If you are living in a city or urban environment, I know from experience, that your top concerns are: space, animals, smells, and neighbors (complaining of smells or critters). You can still compost in these situations!

Compost tumblers are my first recommendation. If you have the space, get a tumbler! We still use ours and it makes the best compost in an enclosed container. No smells and no critters! Make sure to read my Compost Tumbler Basics.

If you live on a patio, vermicomposting might be your best option. You can keep the worms like “pets” and there are complete setups for sale that will keep your process relatively clean and aesthetically pleasing.

If you have an urban backyard, Sam and I are currently using our DIY Pallet Bin design and LOVE it. We actually made our first batch of hot compost in about 2 months! This kind of setup is great for making larger amounts for a full backyard garden. There are also pre-manufactured bins such as the ones pictured below:

As your compost gets closer to being “done” it will start to resemble dark soil. See my tips for how to tell when your compost is finished.

When is my compost finished?

Due to the many factors involved in the decomposition process, I can’t really give you a time frame for when your compost will be finished. My best advice is to go by look, feel, and smell.

LOOK. Finished compost will look like a rich amendment. It will be dark and crumbly, and none of the components should be recognizable (meaning you shouldn’t be able to identify any of the items you added).

FEEL. It should feel like moist soil and not have large pieces leftover. If you do see some large pieces, but the rest looks completely done, you can simply remove them and save them for the next load.

SMELL. Finished compost should smell earthy.

Why does my compost pile smell like ammonia?

If your pile starts to smell like ammonia, you’ve got too much green! Add some brown material and mix it in.

Ready to start composting?

Composting and gardening fit hand in hand. I hope this article has helped get you started on your composting journey. If you’ve found it helpful, please share this post with fellow garden friends or leave a comment below! If you want to read more about how we use compost and other amendments to build healthy soil organically check out Amend Your Soil Organically ~ 5 Things To Do.

You can find many of the items that we used in our compost system on our Garden Supplies & DIY Amazon List.

Meet Randi

Urban gardening is my jam. I’m Randi, California girl who obsessively gardens to grow food and flowers around my urban home. Seasonal, simple living is what inspires me~ I hope it will inspire you too. Join me in crafting a life and home connected to the garden Read More>>>>

For Growers & Gardeners from High Mowing Organic Seeds