The HOTBIN was developed to compost all food, garden and grass in the home and garden.
We want to know how it works on an allotment; so this week we’ve enlisted the help of Gil and Steve at their Jesmond West Allotment, and Karin at the Morpeth East Green Allotment to help us test the HotBin.
Tony went out to set them up with the volunteers this week. Before we started we checked the temperatures of the heaps around the allotments. They were ‘cold’ (very), with ambient (5C) in two, and 8C in centre of a big full 1m3 heap. There were plenty of compostable materials around in existing dalex/plastic cones and wooden bins on the allotments so both HotBins were filled to the three-quarter level. Some of the materials added were mushy wet fruit and vegetables (bits were anaerobic smelly), lots of stalks (cabbage/broccoli) and stems from raspberries etc. Also some shredded paper (Karin) and cardboard (Gil).
We basically just ‘hoofed it all in’, and in this instance, we did not cut or chop things up – we wanted to compare current composting taking typically 12-34 months with the same waste in a HOTBIN. We used the ‘winter heater’ in one HOTBIN and not in the other. We’ll report back on temperatures each week or so.
What are the allotment users composting objectives and requirements
- Compost – humus for helping soil fertility, reducing fertiliser, increasing water holding
- Clear up waste – very few allotments get a ‘waste collection’ so there is a need to reduce and remove plant waste
What’s different in an allotment over the house/garden?
- Volume of waste – allotments tend to produce a lot, and on a highly seasonal basis – ie spring & autumn clear ups.
- Additions to the heap tend to be ‘once a while’
- Not necessarily the time (or inclination) to chop or shred waste, on the whole just want to dump it on the heap.
- There is either a lot of turning (active) or none at all (digging out after 12 months and restarting new heaps after scrapping out).
- More weeds such a couch grass and dandelion
- Some (but not all) will take caddies of vegetable peelings etc down depending on the location etc
Possible HOTBIN advantages / disadvantages?
Space – One observation is that each plot (approx 250m2) has between 2 and 4 heaps taking an area of 2m2 per plot. On a site of 50 plots, that’s 150 compost bins, and a whole plot used for composting. If we can arrange a ‘communal system’ and keep all HotBins composting at 60C, then this could reduce to 8 HotBins.
Economics – Many allotment owners enjoy growing their own food, but we can’t avoid that it is also a ‘low cost’ activity with average rents being £50/year. Costs including compost bins need to be kept under control. There could be a communal saving – 150 standard bin @ £20 each= £3K v 8 x Hotbins @ £138 each = £1K.
Ease of use – Allotment owners are used to hard work, but our gut feeling is they would rather be growing and using compost than turning heaps.
It looks like the Hot will be put through its paces on the allotments and it will interesting to hear back how the HotBin and the users get along!