The compost heap
The most simple form of a compost site is a compost heap. You simply place your
organic material at some place in your garden and build a heap there. With
time, it will turn into compost. Just add new material on top of the heap.
There are some things to consider: First, heaps spread out as they get taller.
This can be stopped by installing a frame around it, made out of wooden boards,
for example. Then composting on a heap isn't the fastest method because
the heap has a big surface where it looses heat and moisture. With rain,
minerals in your compost are washed away if you don't cover it. Finally, it
may attract rodents as all the ingredients of the heap are freely accessible.
The fenced compost heap
This type of compost site is a simple extention of the compost heap: by providing
a fence (like on the picture to the left) or a solid plastic wall with ventilation holes put up as a cylinder or box the compost is kept from spreading
out when the compost stacks up. Additionally, it is easier to cover the compost
site with a plastic foil, board or cardboard piece to shield it from rain.
The plastic version to the right is available at no cost from the City of
Columbia to all its residents.
The compost box
The compost box is similar to the fenced compost heap. But the fence or plastic
cylinder is replaced by a solid box made out of wooden bars or plastic.
This type of compost site offers the advantage of increased stabilit compared
to the former types. You could use a lid that fits the box' top to protect it
from rain. Some other features of this type of composter could be:
- an opening at ground-level at one of it's side walls to remove finished compost
- 'stacking': the compost site is made of elements (or 'rings') of wall material that are stacked on top of each other like Lego blocks. This way you can easily increase the height of your composter as soon as it needs process more organic material (like in autum, when you need to take care of all the leaves). Additionally you could stack up a second composter from the elements when needed.
A very sophisticated version of the compost box is the 3-box-system:
This composter combines several concepts: it integrates three box-composters
that are protected from rain by their lids or roofs. Because it has three
sections, it is convenient to use it for composting: use one section (for example
the left one) to compost, leave the middle section free and use the right section
to store excess leaves, grass clippings or other material.
The middle section comes into use when you turn your compost over simply by
taking it from the left to the middle part (and back, with the next turn).
Compost bins
Compost bins are very common. The most simple type of a compost bin is made of
old trashcans or barrels. Some holes need to be drilled in the bottom and side walls
of the bin to ensure ventilation and ground contact (the latter to get the
microorganisms and earthworms into the bin).
Using a lid keeps rodents away. Some versions of commercially available bin
composters have doors in their side walls on ground level that make the removal
of finished compost very easy (the Earth Machine on the picture to your right is
an example).
If you live in a very urban area, neighbours might be concerned about odors or
insects that may appear due to the composter. In this case, you can use a closed
compost bin with no or only a few ventilation holes. Due to the lack of fresh
air, the composting process is slower but doesn't affect your neighbours if they
live very close.
Compost tumbler
The compost tumbler is one of the fastest composing devices. It is usually made
of a large drum (an old barrel), a frame and some mechanism to turn the drum.
There should be a lid to add material and small ventilation holes in the drum's
wall.
By simply turning the drum you mix the material in it efficiently. The drum shields
rain, rodents and heat. And even the finished compost is easily harvested:
it falls through the ventilation holes to the space underneath the drum where
you can place a box to catch it when turning the device.
On the other hand, this is the most complex device to build or most expensive
one to buy.
...and for the more adventerious there is always vermicomposting