There are a number factors to consider when buying building a compost bin. Compost can be unsightly to some. If you don’t get the ingredients right they can smell bad. For these reasons, and others, piles tend not be in people’s front yards. These points should be considered when locating your compost pile. Additionally, you may want to place the pile strategically in your yard so it is nearest the main sources of material, or so it is nearest the places where you intend to use the compost when you are done. Composting can take a good amount of space, too. Additionally, you may want to consider these points:
- It’s usually best to have the pile in contact with the ground, as this will allow microorganisms and worms to get into the pile more easily.
- The pile needs decent drainage. Putting it in a low place or a hole can create a pool of standing water at the bottom of the pile that suffocates microorganisms.
- Aeration is also important. Some people raise the pile several inches off the ground in order to increase air flow underneath. This can be done with pallets, a wire base, or a bed of branches. Others improve aeration by drilling holes into PVC pipes and inserting a couple of them through the middle of the pile. If you do a good job of layering different kinds of materials in the pile you may do enough to create air channels that you don’t need to worry about other means.
- Keeping all compost piles in the same place year after year allows a buildup of microbial activity in the ground underneath, which makes it easier to get new piles going each year.
The Size of the Compost Bin
As mentioned earlier, there is a minimum size for your compost pile. At the very least your pile should be a cubic yard. A pile this size is large enough to have layers of insulation so that the middle of the pile will be able to heat up even in cooler temperatures. Piles that are too small don’t really have enough material to heat up.
On the other hand, piles that are too large have disadvantages, too. A pile that is much wider and taller than 5-6 feet will not have good air flow into the center of the pile. Or, the pile may heat up too much in the center, killing off the microorganisms. Consequently, the ideal size of your pile lies somewhere between 3-5 feet wide, tall and deep. I prefer a pile that starts out about 5x5x5, as this is the upper limit, and the pile will quickly shrink in the first week or two.
To Layer or Not to Layer
Although layering the pile may be the ideal, it is not always practical. Material usually becomes available as one kind all at once. For example, you usually have no leaves to add to the pile until fall, and then you suddenly have lots of leaves. In order to have a layered pile you would need to keep piles of different kinds of ingredients around, and then shuffle them all together like a deck of cards to get the layered effect. Again, this would be the ideal method, but is not always practical.
As stated before, if you can layer your pile because you are accumulating lots of different types of materials all at once (like in the fall), keep your layers about 6 inches thick and alternate between “green” layers of fresh vegetable matter with dry “yellow/brown” layers of weathered material. A typical approach would have you layering one kind of vegetative material, such as straw, a layer of a different kind of vegetative material, such as grass, a layer of animal matter (such as manure), a thin layer of soil or finished compost, then some water, and repeat.
After a few weeks your pile may shrink by 20-60%. You can raise the level again by piling more layers on top if you like. When you reach the maximum height you can place a layer of insulating material on top. Good options for this are sod (as mentioned before) or a heavy layer of straw, hay or leaves.
Buying or Building a Compost Bin
There are a number of bins, boxes and tumblers on the market and these are all fine, or you can build your own out of a variety of materials. You don’t need them, however. In fact, you don’t “need” anything but the pile. However, it is nice to have something in place to keep the pile in one place, to keep things a bit more organized and neat.
A number of homemade varieties of bins and boxes have been used by avid gardeners over the centuries. The most common is the wooden “box”. As the name suggests, the bin usually is in the shape of a cube, with three walls and an opening in the front, as well as being open on top. If you have the desire and the means, a nice compost bin can be built with 2×2 posts and 1×6” boards. Just make sure you leave small gaps between the slats to allow air to get to the sides of the pile more easily. The front can be completely open, but a low (1 foot high) front is nice as it prevents spillage. Because wood decomposes pressure-treated wood is recommended. For a simpler approach you can simply attach three pallets together to form the three walls of the bin.
Wire mesh bins are easy to build and very nice to work with. A wire bin is usually made out of fencing or chicken wire. A wire bin loses more heat than a wooden pile, so may decompose more slowly. An advantage of it is that it is easy to lift the bin up and over the pile when you are ready to use the compost. Other materials that can be used to build a compost bin – snow fencing, cattle panels, hardware cloth, cinder blocks, bales of hay, piles of sod.
Most people like to build a two or three-bin system. This allows you to turn the pile easily. The way it works is pretty straightforward. In the first bin you have your ingredients that you throw into the pile as they become available throughout the season. When that bin becomes full, you turn that pile into the second bin, and then pile new stuff on top until that pile is full. This 2nd bin pile will get nice and hot and do a lot of good decomposing. In the mean time you can add new material to the first pile again. When the 2nd pile is ready, turn it again, this time into the 3rd bin. By the time the pile is done in the 3rd bin it is ready to be used in the yard. There are variations on this, but that is the general idea.
A compost bin can be constructed from many other materials, whatever you have available, frankly. Branches, PVC pipe, chicken wire, slats of fencing or decking materials, and pallets are just some of the types of materials that have been used to DIY compost bins.
Buying a Compost Bin
A number of good ready-made bins are available on the market for reasonable prices. You can use a 32 gallon plastic garbage can or 55 gallon oil drum. However, the best store-bought types are tumblers. These tend to be smaller, but have advantages to them. They are usually made from plastic and are suspended on a stand to facilitate turning of the barrel. The sides have holes for aeration. The lid comes off easily to add materials or to dump it out. They are designed to be easy to setup, and easy to turn even when full.
Although a typical tumbler compost bin is usually only 55 gallons or so (about 1/3 of a cubic yard), they are usually very fast at producing usable compost, sometimes in only 3-4 weeks. Another advantage is that, because it is an enclosed container you can usually include food scraps, including meat materials, even in areas with strict ordinances. Check your area’s laws to be sure. These are ideal for people who are physically incapable of doing the manual labor required to turn or stir a pile.
Tumblers may be hard to find at the local store, but you can get a good one online, believe it or not! An example of a very good one is this one from Amazon.com. It is marked down in price and is free to ship! There are a number of different ones out there, but this one has the best overall reviews and seems to be the best all around option.