Many different ways exist to create compost and it all starts with how the compost will be contained. After doing some research, I realized many questions come up about covering or not covering a compost pile and everyone seems to have a different opinion. I have been creating my own compost for quite a few years now and I will share with you what I have learned from my own experience and research.
So, should a compost bin be covered? No, an unfinished compost pile does not need to be covered in most cases. The most important factors for composting are air, water and a good mix of green and brown material. Covering a compost pile could cause a lack of oxygen, trap too much moisture and cause a smelly, anaerobic mess.
Many different factors can affect a compost pile. Some of these factors include location, climate, materials mixed together and the amount of moisture that exists in the pile, to name a few. In most cases, it is not best to cover a compost pile. Many individuals may be covering the compost pile with great success, so let’s discuss the reasons why covering or not covering may be right for each individual situation.
Using a Lid or Covering for Compost
In general, an unfinished compost pile does not need to be covered. I have never covered my compost bins and have had great success with creating compost easily.
Not having a cover allows rain and a larger amount of oxygen into the pile, which is essential to the organisms that are breaking down the organic matter and turning it into compost.
A cover, such as a tarp, is a popular choice I see suggested on other websites. I do not want to suggest that this cannot work because I am sure some people out there are having success with this method. However, depending on the contents and moisture level of the pile, trapping all this material under a tight tarp could cause the pile to become a stinky, smelly, anaerobic mess. The pile cannot receive enough airflow and oxygen if it is covered. If the pile was too wet at the beginning, then all that moisture is trapped and cannot evaporate.
A cover might be necessary for a compost pile for gardeners in areas that receive too much rain. It’s great if the pile can be watered naturally with rain, but at the same time, a compost pile should not be soaking wet all the time.
If this is the case for you, I would suggest more of a hardcover, such as a lid from a bin or a piece of plywood. This would keep the extra rainwater out, but it would not be smothering the pile and would allow for good airflow.
Another great option is to construct the pile under an overhang. Maybe the side of a house or shed has an overhang. This would be a great place for a compost pile for those who live in an extra wet climate. If this is not an option, then think about constructing an overhang over the bin. Even for those who do not live in a wet climate, this may still be a good solution so that the amount of moisture in the pile can be fully controlled.
Would a Cover Help Heat Up My Pile in Cold Weather?
For those who live in colder climates, other considerations and possible benefits do exist for putting a lid on a compost bin. A lid or covering may help insulate and heat up the pile to get the composting process working faster. In this case, an old piece of carpet may be a good idea. This could provide extra insulation, while also allowing oxygen and rainwater through to the pile.
A dark colored tarp could also be used to help warm up the pile. However, be aware that the moisture level would need to be monitored and the pile may need to be turned more often to get more oxygen into the mix. Check out our article When Should I Turn My Compost Pile? for more information on this topic!
Again, based on my own experience, I have not needed to cover my compost bins. I live in zone 6a and we have fairly cold winters. I mix shredded leaves and coffee grounds together to create a hot compost pile and the compost is finished in less than a year.
Once the compost is finished, it is recommended to either use it in the garden soon after, cover it or store it in containers. Rainfall can cause compost to leach nutrients, so make sure that instead of losing them, those nutrients are being put to good use in the garden.
Does a Compost Bin Need Air Holes?
I have stressed that a compost pile needs good airflow, so it may seem that a compost bin should have air holes around the sides. I would say this would help, but it is not a requirement. I would more so suggest that a compost bin be built with whatever materials and abilities are easiest. Focus more on building and layering the materials of the pile.
Having good airflow within the contents of a compost pile is more important than its outside structure. The organic material should not become compacted and the moisture level should be about as wet as a wrung-out sponge.
The best way to assemble a compost pile would be to mix the pile with different sized material. It is great to have small sized material, such as grass clippings and shredded leaves. However, this can tend to matte together and suffocate all the living organisms. Incorporating some larger material into this mix, such as sticks, wood chips and trimmings from bushes, can help create more air pockets and prevent the pile from matting together.
Should a Compost Bin Have a Base?
I would not recommend that a compost bin have a base. A base, such as solid wood, concrete or some other hard material, would prevent worms and other beneficial life from getting into the compost bin from the soil below it.
A solid base also would not allow for adequate drainage and the pile may become way too wet. If a base is absolutely necessary for some reason, consider adding some drainage holes or slanting the bottom so water can run out somehow.
Some people may experience issues with rodents or other animals getting into a compost bin. If this is the case, it may be good to use chicken wire for the base of the bin so these animals cannot dig in from the bottom. The chicken wire or other similar material would still allow for drainage and for soil life to enter the compost.
Another suggestion for animal concerns and issues is to not add food scraps to the compost pile. Food scraps are most likely the primary reason the pile is attracting these animals. Instead, a worm bin would be a much better option for those with many food scraps.
Therefore we do not lose heart, but though our outer man is decaying, yet our inner man is being renewed day by day.2 Corinthians 4:16
Easy Compost Bin Solutions
First, I would like to briefly mention that two kinds of composting exist: hot composting and cold composting. In short, hot composting requires at least a three foot by three foot by three foot area of material in order to “heat up”. This will create finished compost quickly. Cold composting, on the other hand, is more of a pile it somewhere and forget about it type of approach, which may take one to three years to start receiving finished compost. Both options will work, one is just faster than the other.
Most people prefer hot compost so you can get that precious “black gold” as quickly as possible.
Palette Compost Bin
I built a two-bin compost system (see the main picture) out of palettes. I got the palettes for free and it was a piece of cake to assemble. All I used were adjustable zip ties to attach them together. This method allows me to unzip a door on each side where I can easily access the pile to turn it.
The contents of my pile include a mixture of shredded leaves and grass clippings and then I layer used coffee grounds in between when filling up the bins. I fill up both sides to the top in the fall, turning when the pile starts to cool down. By early to mid-summer, the contents of the bins has reduced enough where I can combine them into one side of the bin and start another compost pile on the empty side.
I use the finished compost in the fall by spreading out one to two inches on top of my garden beds. I also sift and store some of this compost in five-gallon buckets for me to use as an ingredient in my seed starting and potting mix in the late winter for all my seed starting and Spring planting needs.
Other compost bin considerations
- Wire mesh. Any kind of wire mesh or fencing material can be used to create a cylinder hoop to contain compost. This is a quick and easy solution and does not require a permanent structure.
- Large trash can. Many holes should be drilled in this container for good air flow and drainage. Mix and turn compost either with a garden fork or roll the trash can around in the yard!
- Compost tumbler. A compost tumbler can be purchased online or in a garden store. This is the same idea as the trash can with an easier way to turn the compost just by turning a crank.
For more links and information on the composting products we use and recommend, check out our Best Compost Products page!
Do compost bins need to be in the sun or shade? A compost bin can be placed in either the sun or the shade. Either way will allow great compost to be created if green and brown material is mixed correctly. A sunny spot may help heat up the compost bin, which would help to produce compost more quickly, but it is not required to be placed in the sun.
Do you need two compost bins? I would definitely recommend a two-bin composting system if space allows for it. This allows a pile to be built completely, and then while that pile is in the composting process, new material can be added to the second bin.
Do compost bins smell? A compost bin will only smell if an anaerobic environment has been created. This occurs when the material is too wet, lacks oxygen and/or contains too much green material. Otherwise, if those components correct, the compost bin will not smell at all.