Designed to make composting easy
Traditional bins, effectively used by generations of gardeners retain an important place especially in larger gardens. Here I've examined different designs to help you choose the best for your particular situation.
The Black Cone Bin - U.K.
holds 12 cu ft. One piece plastic moulded with a tight lid and removable bottom door for access to finished compost. The material at the bottom may appear to be unchanged at first, but delve deeper and you find black compost. To aerate plunge a garden fork down through the top and pull the handle in clockwise and anti-clockwise circles. You can also lift the whole bin up off the heap then, spade the contents back in through the top.
holds 12 cu ft and occupies a space 28" wide by 31" high. An open heap this small just wouldn't get hot. But the fully enclosed container with lid works by retaining heat and moisture to speed decomposition. It also protects from excess rain water and leaching. To get the best results you need to chop up the material, and an activator helps too. This link may offer you 4 lbs. of 'Compost Alive' included with your 'Compost Digester'.
The Space Saver Bin - U.S.A.
this advanced design is a compact 20" x 22" x 33¾" high and holds 7 cu ft. Comes as a flat pack with self assembly. The obvious advantage of flat packs comes in transportation and storage. Once assembled it behaves as a solid single structure. A real mini bin convenient with small regular amounts, e.g. vegetable food scraps, grass cuttings and weeds from a small garden. Its big brother is the Pyramid Composter - see below.
You don’t mind giving worms access through the bottom but you may wish to restrict access to burrowing vermin. Fortunately a
is available for these Pyramid bins.
Air vents are more important with larger volumes. All these types of bin should be filled as much as possible, so it’s important not to select an oversized bin.
Aeration is vital with all composting. You should also regularly break apart tough thatches of organic matter. Aerating tools have blades specially designed to help with this.
Aerating tools have been designed specially for stirring up the heap. >From the U.S.A. we have an 2 handled aerator with 2 sets of folding stirrer wings and a heat smart aerator that indicates the temperature.
Warmth: heap is protected from wind. Warmth is retained because of internal water conservation. Black colouring absorbs the maximum heat from sunlight giving warmth for a good start. As with all composting, green organic matter is required to get higher working temperatures. If fresh new material is not continuously added the heap may cool down.
Smaller Size: The above properties usually mean that high temperatures can be achieved with smaller amounts of organic matter.
Air: Many heaps have ventilation gaps, but oxygen shortage is only caused by poor consistency of organic matter. Shred material, include twigs and fibres with the green matter, and aerate the compost. Some plastic bins are designed to tumble and so mix and aerate the contents.
Organic matter: Should be cut or shredded.
Smell: Ironically air vents are the most important design feature in reducing odours. Otherwise good containment including a lid keeps any odours relatively confined.
Speed: Depends on the type of material added. Can be fast with completion in 4- 6 weeks. A significant reduction in volume over a week or so is usually apparent. Even though decomposition completes quickly and the bin can be emptied, the compost is best left for several more months to meld.
Continuous composting: As long as the bin is full smaller amounts can be added at the top and compost continuously removed from the bottom - useful when you add grass cuttings from a small lawn. If fresh new material is not continuously added the heap may cool down. Don’t get a bin too big for your needs.
Mobility: Single piece plastic bins are easier to move. Some tumblers can be rolled to a new position without emptying.
Situation: While modular and continuous composters generally have no bottom, the material inside tumbler composters is fully contained and these can be set up over any surface. They could even be located in a garage or house porch.
Durability: Modern recycled plastic appears to be durable with no need for wood preservative. They keep your heap neat and tidy.
You compost in batches, but concentrate on softer stuff and avoid woody fibrous matter that takes longer to compost. Obviously the last addition has to be composted before emptying. When ready the whole bin can be emptied before starting again.
They can be used near the house for regular addition of kitchen waste. Some designs could easily be sited in a porch, out-house or garage. The contents are not in contact with the soil so adding an activator may be more important. Some tumblers can be rolled to the site where you want to use the contents.
Whether it is 5 or 8 cu ft, you will still need to apply some energy to rotate any of these bins. When ready roll it to where the contents are needed.
is more friendly in appearance when placed in your garden next to your house or plants. It has a modular design and comes in flat pack form for self-assembly to 29" x 30" x 35" high; I make that 17 cu ft. It is made of tanelised timber with a 10 year guarantee. It has a removable front access.
Once constructed bins that slot together with wooden slats are not as portable, so they need to be well sighted at the start.
25 cu ft is considered about the minimum size for the traditional low tech heap to heat up. Wood is a good insulator but with good ventilation you may need excess green matter and perhaps an accelerator to reach a good temperature here. I would happily use this model with a 1" layer of horse manure for every 9" of fresh green garden waste.
It is often sensible to have 2 or 3 bins. One bin is used to collect material. (Having seperate piles for green, and woody etc... is useful) Then make your compost heap in the 2nd bin, while a 3rd bin is waiting to be emptied.
The above easy to assemble modules are available as single bins, as an add-on unit, or you save when you start with 2 modules.
Special bins are available for making worm casts You don't even need a garden and worm casts are great for top dressing house plants.
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