How To Compost With The 3 Bin Compost System

Using a 3 bin composting system makes it easy to manage, turn, aerate and use. Learn more as we talk about how to get started with this system.

Everyone loves to say they compost but do they really know what they are doing? This 3 bin system works great for us and provides a bit of fresh, wonderful compost for our gardens each season.

3 bin system post

Benefits of a 3 Bin Composting System

Now, I love composting, but one of the problems I’ve had in the past with the “traditional” style of composting is that the compost never truly breaks down all the way. Since we’re always adding new ingredients to the pile, it is always “cooking.”

As a result, you never actually know when the compost is ready to be used in your garden.

That might not be a huge problem if you’re adding mostly yard waste and kitchen scraps to the compost pile. These are things that, in most cases, are just fine to add fresh to your garden.

The problem arises when you are adding lots of ingredients to the compost that aren’t exactly safe to go on your garden “raw.” By that, I mean things like chicken manure and other animal manures.

These are great ingredients to add to a compost pile as they add tons of nitrogen, but when added raw to your garden (meaning they haven’t had the chance to break down for several months) they can overload your garden with nutrients and burn your plants.

Another benefit of this kind of compost bin system is that it will reduce the weight of the material you are putting inside.

If you don’t want to spend a lot of time turning heavy batches of compost every week, you may want to consider this kind of system. There’s less waste to deal with all at once.

Since you aren’t constantly adding new materials to every pile, you aren’t unnecessarily prolonging the decomposition process.

How to Build a 3-Bin Compost System

Now, you can easily run to the store and buy a 3-bin compost. This will save you some time and effort, since everything will come hooked together and ready to go. However, there’s really no reason to do that, since you can build one of these compost systems for very little (if any) money.

Build a 3 Bay Compost Bin STEP by STEP

Here’s an easy way to build one. All you need is a rake, a shovel, and a hammer, along with seven untreated pallets and some nails.

Go ahead and level your compost area with the rake and shovel. Lay down a few sheets of cardboard to repel weeds (I’ll tell you more about this later in the article) and stand up two pallets to create a 90-degree, L-shaped angle. The thicker pieces should be parallel to the ground.

Then, nail your pallets together where the top and bottoms meet the slats. Attach a second side pallet to create a three-sided, open-faced box. Hammer in your nails until you have three attached, open-faced boxes.

You can choose to add a front pallet to each of your bins, or you can leave it open. You can also add a pallet “roof”, if you’d like. Just make sure there’s a way to keep animals and other pests out, and a way to allow moisture in.

Don’t forget that you’ll also need to be able to get into your three bins to add ingredients, turn the compost, and move compost out on a regular basis.

How To Use a 3-Bin Compost System

As the title suggests, we use three bins to complete our full cycle of composting. The 3 bin compost system involves either buying or building three bins or boxes. They can be linked or merely positioned side by side.

This method is perfect for a gardener who can easily turn a compost pile with a pitchfork, as well as a garden whose plot produces tons of food and plant waste.

The first bin holds all of our “new” stuff. We collect kitchen scraps and toss them in fresh. We clean the chicken coops and throw all the waste in. We take down old and dead plants from the garden and add them to bin number one as well.

The theory behind composting in the first bin is similar to what you might do if you were composting in a more traditional sense. You’ll add your compost materials, layering green and brown ingredients whenever possible.

Once the pile starts decomposing, and it’s around 3x3x4’, that’s when the differences start to come about between this 3-bin method and a traditional method of composting.

Some examples of ingredients you might add to your first bin include:

  • Plant trimmings
  • Weds
  • Eggshells
  • Animal manures
  • Coffee grounds
  • Tea bags
  • Kitchen scraps
  • Paper
  • Seaweed
  • Grass clippings
  • Dried leaves
  • Corn stalks
  • Wood chips
  • Coffee filters
  • Pine needles
  • Shredded branches

We are sure to turn the waste inside the bin frequently and keep it moist, but it is by far the yuckiest bin – filled with rotting food and all manner of bugs, who just love the stuff.

One thing it is NOT, however, is smelly. An overly fragrant compost pile is a bad sign. If everything is in balance and properly covered, your compost pile should not smell.

If you notice that the bin is getting dry, you might want to water it. It should be like a sponge when you squeeze it.

If there’s more than a drop or two of water when you squeeze it in your hands, it’s too wet – add a layer of soil or dried leaves and turn it to get some of the extra moisture out.

In the first compost pile, the bin is building up fungal and bacterial activity. The temperature will increase naturally, and all you’ll need to do is turn the material regularly, and keep an eye on the moisture and heat of the bin. It can take a few weeks for the pile to really get going, but usually, it won’t take more than a month.

This is when the fun begins. As the waste in bin number one reaches the top, we prepare to move it to bin number two. In moving all of the contents of bin number one to bin number two, we are able to really mix up and aerate the decomposing matter. This is important for a proper and expedient composting system.

After the contents are moved, we are left with an empty bin number one. We will begin to fill bin one again with the “new stuff,” but we will never add new material to bin number two. The only job bin number two has is to continue to compost and break down.

When All Three Composting Bins Are Full

As bin number one fills again, we move the contents of bin two to bin number three and so on and so forth.

By the time bin number one is full for the third time, bin number three should be fully composted and ready to use in the garden. *Remember* New material is ONLY ever added to the first compost bin.

All of this will depend on how quickly you create the material that needs to be composted.

Some people will find that they need much larger bins or need to simply resort to large piles that are turned and shifted. These bins have always worked great for us, but we live on .15 acres in a large urban city, which may be very different from your situation.

You may also wonder how to know if bin number three is truly ready to be used. The easiest way to tell if your compost is done is by sight and feel. Does it look like compost and is it cool to the touch? If you can still discern large chunks of food or specific plants, it needs more time.

The rule of thumb to live by for the third bin is that it should contain only unrecognizable materials. If you still see a chicken bone or a banana peel hanging out in there, it’s not ready to be used.

Also, if it is hot or warm to the touch, then it is still decomposing. Don’t use it if it isn’t finished. It can burn your plants, and they will die, which would be terribly tragic.

Other Considerations

There are a few other tips I can give you when it comes to using a 3-bin compost system.

For one, you need to be especially carefully about weed seed getting into your bin. You can’t really move your system once you’ve gotten started, and the compost sits directly on the ground.

Therefore, it can be easier for weed seeds to infiltrate and you can then transfer those seeds directly to your garden – something you really don’t want to do.

To avoid this, you might want to lay down a few sheets of cardboard before you set your 3-bin compost system in place.

This will help suffocate weeds and the cardboard will break down nicely, leaving you with rich, fertile soil beneath your bins (a plus if you decide that you ever want to plant where you once had your compost piles).

Another word of caution? Moisture. Moisture can be problematic.

If you live in a particularly wet area, or during abnormally wet periods of the year, you may find that your compost pile gets too wet. While a compost pile needs to be somewhat wet in order to get the microbial action really going, too much moisture can spell disaster for a compost pile.

Therefore, you’ll want to take one of two steps.

You can put a pallet over the top of the bins, which will let in some moisture but not too much. You can also leave the bin open on one side. This will let some moisture infiltrate but will still give you a spot where you can get your pitchfork into the bin to shovel out the compost and to turn it on a regular basis.

The choice is yours! Whatever you do, though, just make sure you take the time to factor in how water might affect your compost pile.

More Composting Articles

3 bin system pinterest

updated 09/08/2020 by Rebekah White

15 thoughts on “How To Compost With The 3 Bin Compost System”

  1. This is completely brilliant!! We have one fresh and new compost bin that we continually add to, and one long and slow compost bin for our straw from the chicken run and yard clippings. I’m going to try adding another in between and see what happens. We have to keep all of our fresh stuff in a steel garbage can with holes cut into it, because we have a lot of issues with rats here in the city. Do you guys have problems with that as well? By the way- I just stumbled upon your site over on Passionfruit, you may be getting a request for advertising from me soon if I can come up with the extra cash! Very nice site! 🙂

  2. Great post! I wish I had this type of system. I have a long compost pile and I start at one end with fresh stuff and I slowly move it up as I turn it….but separate bins would be so much easier!

    Thanks for linking up with Green Thumb Thursday. I hope you’ll stop back again this week!


  3. Hi,
    How would you incorporate shredded newspaper into the system? We use it between the rows in our garden which has mostly gumbo muck/mud . It lets you walk in the rows after a rain but is not good for mulch really.

    But we are getting to much lately.
    Nice post too.
    Mike and Sheila

    1. into the bins, we would shred it up. We also lay some down between the garden beds and then cover with mulch to help create a walk way, control some weeds and such.

  4. One extra bit of info for people who live in a dry climate like ours. A semi-arid bin should have little or no airflow, such as gaps between the slates, screens, etc. Our low-humidity environment — ranging from 3% to 44% RH — sucks all the moisture out of the pile in just a few hours. A composter won’t work properly if the materials dry out too much or too quickly. On the other hand, a semi-arid composter is designed to retain moisture, so you will need to turn over the material frequently so the bottom of the bin does not become soggy. It’s more work to compost here, but the outcome is as satisfying as in higher-humidity climates.

  5. I like the 2-3 bin system and it seems that it would be the easiest to manage for newbies. I’m trying to start a compost in a highly humid environment. What do you suggest?

    Also, to keep animals out – including mice/rats – but other wild animals, what materials do you suggest work the best?

  6. Just built three 4x4x4-foot bins and our property is on the Island of Hawaii. Do we need to drill holes on the side of the bins for more airflow?

  7. Thank-you!! I just set up my 3 bin composter and this is exactly the information I was looking for. Just one question, do you layer a ratio of brown and green items in bin one? If so, what ratio, and do you wait a while before you begin turning it?

    I appreciate this post so much!!

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