As it is becoming customary to celebrate Apple Days across the country including the pressing of apples to make juice I felt it might be useful to expand the advice on composting apples.
Any composter who does
not have their own fruit trees or access to the pulp from an apple day may find that the local allotment, community garden, local park or farmer with a small orchard may be happy to allow the collection of bruised or rotting windfalls. In towns a local
juice bar may be pleased to have the pulp removed for free.
Under normal circumstance apples can be added to the composting as and when they are no longer suitable for eating and this includes the occasional windfall during the summer months. Chopping
the apples will of course speed the composting process. However in the autumn larger numbers become available together with the mushy pulp resulting from juice extraction a slightly different approach is needed to deal with the sudden influx of
“greens” into the bin or heap. If creating compost heap or using a New Zealand bin the minimum size recommended is 3cu feet. Smaller heaps will breakdown more slowly and will need more frequent turning to keep the composting process working.
Where there are a lot of apples it is best to layer them with browns and continue making alternate layers of apples and browns until all the windfalls have been used. If you only have a few trees it might be better to collect
the apples in some kind of storage container i.e. a bucket or bin so that you have enough to make several layers about 4” thick at the same time. If possible other greens should be added at the same time as the chopped or pulped apples to introduce
air spaces and variation into the green mix.
Creating the correct green brown ratio is important so as to prevent the apples fermenting and producing an unpleasant smell. One part green to two part brown material is recommended but if the fruit is going
to form a high proportion of the compost heap the addition of a bulking agent to absorb the liquid and provide plenty of free air spaces (FAS) to maintain aerobic decompostition is recommended. For more details on bulking agents please see the page on
Although autumn leaves are normally used to make leaf mould they do make an excellent component of the brown layer. Sawdust from a vegetarian pet, such or chicken can also be
added. I also add shredded computer paper. The high liquid contentof fruit pulp makes an excellent wetting agent for dry hay and sawdust A shovelful of finished compost from an adjacent bin, plain garden soil or manure can be added to kick start
the microbial activity that will turn the apple waste into quality compost. As with most hot composting systems water the bin or the browns at the start of the process and at any time that it looks dry. Turn the compost mix to aerate it and cover with
browns (I use the shredded paper) as this will reduce any smells from the bin and reduce numbers of fruit flies when the lid is removed or heap uncovered
For the first week the material should be turned daily to aerate the material ensuring that microbial
activity heats the content. When turning move the material on the outside of the pile toward the center. This can be reduced as the effect decreases. See the section on hot composting if you have a thermometer monitoring the temperature it can provide additional
interest (especially for children).
Do continue to check the compost condition of the bin weekly. If it becomes to dry it will stop working while if too wet anaerobic bugs will take over and the temperature will fall and the smell will increase. If
dry add water a little at a time, if wet add more browns e.g. dry leaves. After two or three months the compost should be finished dark brown in colour with an earthy smell and no apples identifiable.