Capacity
The best compost bin
design for
the cool tropical garden needs to have plenty of capacity. At
the end
of
the growing season your tropical garden will provide lots of stuff to
compost. There will be all the leaves from Ensete Ventricosum
that have been dug up to overwinter. Any bananas will have
had
their leaves removed prior to being wrapped. Then comes the
frost
and all the tender tropical foliage plants will have been zapped and
will need
composting. All in all this requires a lot of room.
Construction
For the garden featured on this site a double bin system is in
operation. Each bin has a volume of approximately 1cubic
metre.
At times it is a struggle to get everything in.
However
lots of jumping up and down (on the compost) generally gets you through
the tough times. As a result of this jumping up and down the
compost bins
need to be of sturdy construction.
Ventilation
Some of the literature on compost bin designs recommend wooden bins
with large
ventilation gaps (an inch or so) between the boards. This is
theoretically to
prevent the compost heap from over heating during decomposition.
As
discussed elsewhere it is quite rare for the domestic compost
heap
to reach prolonged high temperatures. Even when the compost
heap has
been
filled to the brim at the end of the season, the plant material is so
wet that it does not heat up significantly. During the late
winter phase of
pruning trees, shrubs and cutting back grasses etc., some considerable
heat
is generated, but I have yet to go to the
bottom of the garden to
find a crater where the compost bins once stood. All that
gaps
achieve is to leave you with dry strips of un-composted material when
you come to turn the compost over.
Accessibility
The best compost bin design allows easy access to the compost.
This does not mean through some opening the size of a letter
box.
Even some of the new bigger compost bins made from recycled
plastics still insist on restricting your access. These
designs
rely on the assumption that you will occasionally scrape out a bit of
compost from the bottom and the rest will collapse down. The
best
compost bin design will allow for the entire front to be removed.
With the double bin system, the mature compost can be removed
in
one go. The compost can be piled on and empty border and used
when planting. The front panels are then be replaced and the
front panels from the second bin removed. The compost is then
transferred into the empty bin.
As each bin is emptied completely you are able to wash and re-treat the
inside of the bin with a wood preservative.

The best compost bin designs
allow easy access to the compost.
Location
Another
factor to consider is the location of the compost bins. The
natural tendency is to place them as far out of sight as
possible.
This of course tends to be as far as you can get from the
kitchen
door. One thing to remember is that you will be making
regular
trips to the compost heap throughout the year delivering the kitchen
scraps. Make sure you will not have to wade through mud
during
the winter to access your compost bin. If this happens your
enthusiasm for composting may diminish. The best compost bin
location will have some sort of paved pathway
leading to it.
Also to consider when locating your bins is how easy it will be when it
comes to emptying them. Place them somewhere that will allow
easy access by wheel barrow.
Emptying
and turning the compost heap is quite an energetic process.
You
do not wish to be frustrated by cramped conditions.
When it comes to filling your compost bin:
- Left handed people should use the left hand bin for
filling and the right for maturing.
- Right handed people should use the right
side for filling and the left side for maturing.
This makes life easier when it comes to turning the contents of the
'filling' side into the 'maturing' side.