A new experiment is underway in Bin #4 – we’re following a formula for ’18-Day Compost’. We’ve started with alternating layers of green waste, lawn clippings, bark chips, leaves, shredded newspaper, cardboard cut into approx. 2″ squares, and about 4 pounds worth of coffee grounds.
Picture 1 shows the materials laid out and ready to go. We’ve got green waste and prunings from the plot in the wheelbarrow, shredded paper, bark chips, cut-up cardbord, and we’ve also got two containers of crushed egg shells and dried & ground banana peelings. We’ve also held back about a half-wheelbarrow of the compost that came from the composter to be used as a ‘starter’ for this batch.
We began by layering in 2-inch layers of alternating matter, wetting the layers down with water as we went. Picture #2 shows what a layer of the cut-up cardboard looked like.
When the bin was about half-full, we piled the held-back compost right in the middle of the heap, and then continued to layer in the remaining materials with a layer of brown waste (cardboard and newsprint), green waste, coffee grounds, leaves, and a scattering of crushed egg shells. Finally, we wet the whole pile to get everything nice and damp.
The final bin appears in picture #3.
Following the formula, we’ll let the whole batch sit undisturbed for four days, and then begin turning it every couple days, bringing the hot inner core to the outside and putting the cooler outer layer on the inside. With any luck, we’ll have a bin full of rich compost in about three weeks. Watch for updates!
September 14 Update: Temperature 126F. Turned to move dry material to the middle and added more water.
September 18 Update: Temperature lower at 114F.
September 21 Update: Turned compost moving warm centre to outer edges and dry matter from the outside back into the middle.
September 24 Update: Compost is breaking down very nicely and cooling off to the point where there are hundreds of earthworms already active in the mixture.
Sept 24th inspection
October 11 Update: We unloaded four wheelbarrow loads of beautiful rich compost from the bin. 33 days from start to finish – not quite the 18 days ‘as advertised’ but still pretty quick for this time of year, and certainly faster than letting it cold compost. We will definitely do this again.
We added three loads of compost to the plot, and used the fourth load to re-start the composter for another batch. We’ve added leaves, greens and waste from the plot, shredded newspaper, grass clippings, and some must left over from making a batch of wine. It’s all layered in like a big batch of lasagna, and we’ll wait until spring to see what happens with this load. We won’t bother trying to maintain a hot compost mixture through the fall and winter, but we still hope to get three or four more loads of compost out of the bin in the spring.
Over the past two years we’ve added 8 wheelbarrow loads of compost to the plot, raising the north-west corner of the plot by about 8 inches and getting it up out of the standing water that forms in front of the plot.
Three wheel barrow loads of compost added to the plot.
Final results October 11
Maintained by N3-89-90
This compost box has been in service for over 18 months and is being used as a ‘hot’ composter. The initial loading consisted of alternating layers of green waste, dried plant material, garden soil, egg shells, newspaper, cardboard, coffee grounds and some manure. The contents were watered down and left to sit for about 72 hours when the temperature was checked. Internal temperature was maintained between 130 and 140 F while the contents were turned over and in about 7 weeks the entire load was reduced to rich black compost. Approximately 80% of the compost was removed and added to the garden plots, and another batch was started using the remaining black earth combined in a layered fashion like the original start-up.