Good garden compost is not considered Mother Nature’s brown gold and hobby gardeners’ money box for nothing. Invisible to the human eye, an army of microorganisms in the compost heap are busy turning waste into natural fertilizer and rich humus. Depending on the size of the compost heap, this biological process can take a year or more. In a closed high-speed composter, various factors – above all heat – cause a significant acceleration of this impressive nutrient cycle. It is primarily allotment gardeners who benefit from the advantages of a thermal composter. Clever bargain hunters among them take practical instructions and simply build a quick composter themselves.
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choose location
On a large plot of land, the hobby gardener usually has a whole series of hidden parking spaces for an open wooden composter, which are not in the field of view of the viewer. In the small garden, on the other hand, there is often a lack of a hidden location for the compost heap, so that the owners reluctantly do without it because it disturbs the look. That doesn’t have to be the case, because a lockable quick composter in a subtle, dark green or grey-black design is sufficient for storing garden and kitchen waste in tight spaces. In order for the container to live up to its name by producing the desired humus and fertilizer more quickly, heat, oxygen and some moisture are required. Accordingly, the following requirements should be met at the selected location:
- Sunny to partially shaded, airy location.
- Loose, unsealed soil without waterlogging.
- At least 50 cm distance to the neighboring property.
- Easy access to the lid and removal opening.
Unlike a conventional compost heap, a thermal composter often has a bottom. This reliably prevents infestation by mice or rats. Ventilation slots on the side or in the bottom of the container ensure the necessary air circulation. Without an adequate amount of oxygen, rot sets in, which not only significantly disrupts the natural process of rotting, but also brings with it the dreaded odor.
Build your own quick composter
A plastic barrel or a cheaper metal barrel with a lid are best suited for use as a quick composter. The cover is of essential importance, because temperatures of 50° to 70° Celsius occur inside the closed container during the warm summer months. Thanks to this heat development, rotting accelerates to a period of a few weeks. This rate cannot be achieved with an open compost.
Material list:
- 1 barrel (plastic or metal) with a volume of 75 to 240 liters.
- Maybe a piece of chicken wire.
Tool List:
- Lochbohrer
- jigsaw
- 1 flap hinge
- 1 clasp
- screwdriver and screws
Instructions on how to do the work
Before the quick composter is positioned at its location, it gets a few air holes on the side and 2-3 slits in the bottom so that a mouse cannot sneak through. If you want to be on the safe side, you can also lay out wire mesh on the sole inside the container. In the next step, a flap is installed near the ground, from which finished compost is skimmed.
Prepare removal flap
- Cut out a sufficiently large piece from the side.
- Attach the hinges to the bottom edge of the flap and the clasp to the top edge.
- Alternatively, improvise with small holes and binding wire and a furniture knob.
The container is filled by briefly lifting the lid. It is important to note that both covers are always closed again so that the heat that forms cannot escape. Only the holes and slots are responsible for ventilation.
Build a quick composter out of trash cans
Resourceful hobby gardeners who own a 240-liter rubbish bin can easily convert it into a thermal composter.
- Remove cover, wheels and axles and set aside.
- Saw out the handle on the cover and have it ready.
- Saw out the center piece including the indentation plus 3 cm from the lid.
- Turn the garbage can over, place the sawed-out lid on top and mark.
- Now saw out the insertion opening approx. 2 cm smaller than the marking indicates.
- Place the cut-out piece of the lid on the marking and fasten with the hinges.
- Then attach the handle using blind rivets and washers.
The required air holes are drilled with a diameter of 15 mm in the collar edge of the upside-down bin, which is now resting on the ground. The following work step deals with the construction of the removal flap, as described above. This almost completes the transformation of the trash can into a quick composter. Finally, the hobby gardener lays out a wire mesh at the intended location and places the container over it. Since there is no bottom in this variant, he fills in coarse material such as brushwood or chopped material as the first layer.
Drum composter – the high-speed version
A quick composter delivers mature humus and natural fertilizer more than twice as fast as a classic compost heap. Of course, a drum composter steps up a notch in this process. The secret lies in the interplay of heat, air, moisture and movement, because a simple twist results in an effective mixture of the contents. An additional conversion and sieving is not necessary. Since ready-made drum composters require a fairly expensive investment, the allotment gardener’s desire to build this miracle container himself is obvious.
Material list:
- 1 metal barrel with a volume of 75 to 240 liters.
- 1 PVC pipe, 1.25 m long, size 50.
- Alternatively 1 galvanized pipe of the same size.
- 4 wooden slats or joists, at least 40mm x 70mm.
- 2 squared timbers
- 1 Shopblech
Tool:
- Lochbohrer
- Zollstock
- hammer and nails
- screwdriver and screws
- hacksaw
- Flap hinge and clasp
manual
Drill a hole in the exact middle of the lid and base that corresponds to the diameter of the pipe. Then push the tube through. Some air holes pierce the top and bottom thirds of the container, leaving the middle area untouched at first. The prepared drum composter is now set aside to build the associated wooden frame. For this purpose, 2 of the wooden strips are screwed together and connected by the squared timber in such a way that a stable foot is created, similar to a sawhorse. Now you can hang the barrel in the rack, using the tube as the axis of rotation. An opening is still missing through which the drum composter can be loaded or the mature humus can be removed. In contrast to the quick composter, in this case the filling and removal flap is placed on the side of the container, namely there
Basically, the drum composter is now ready for use. However, the effectiveness of the apparatus is significantly increased if a shovel attached to the inside of the container supports the mixing process. For this purpose, an angle plate is screwed to the wall directly opposite the opening.
Over time, the barrel will gain weight, making it increasingly difficult to rotate. If you don’t feel like struggling with it, you can simply add a twist grip:
- Drill a one-inch hole through one end of the torsion tube.
- Push a round, 60 cm long metal rod of the same thickness through there.
A hose insulation placed on the ends ensures that the handle fits better in the hand.
Thermal composter with thermal insulation
In medium-sized gardens, experience has shown that a volume of 240 liters, such as barrels and garbage cans, is not sufficient. A larger volume, on the other hand, heats up much more slowly, even if the container has a cover. The solution to the problem lies in the construction of a thermal composter that retains heat thanks to an insulating layer of air. The secret lies in the use of insulating panels, as they are also used for facade insulation.
Material for an 800 liter composter:
- Plastic insulation panels for outdoor use
- Insulation board 3 mx 1.50 m as cover
- Perforated base with 10mm x 10mm holes.
- 1 plastic handle
- 8 angle profiles 50x50x3 mm, 750 mm long.
- 2 hinges for the lid.
- 2 hinges and 1 closure for the removal flap.
- Non-rusting screws.
The number of panels depends on the preferred profile size. They can easily be cut to size using a fine-toothed hand saw or table saw.
The insulation profiles are connected to each other in such a way that 4 side walls are created. These side parts are then screwed to the angle profiles. One angle profile from the outside and one from the inside is fixed with continuous screws. This is the only way to ensure that the plastic walls will withstand even greater loads and not tear. In the groove rows of the panels there are longitudinal grooves with pre-punched screw holes so that the walls can be fastened to the perforated base. On the lid, blind rivets fix the handle, while the cover itself is attached by the hinges. It makes sense to also secure the lid with a pull rope on the side wall so that it doesn’t fall over every time you open it. Of course, the removal flap in the lower container area should not be missing either.
Pre-assembled composter
The specialist trade offers a range of quick and thermal composters, which are delivered disassembled and only have to be fully assembled. The following models consistently scored well in tests:
Graf Garantia quick composter
- 280 liters volume
- With lid and removal flap.
- Price: around 60 euros
Double-walled thermal composter
- 380 liter capacity
- With double-walled insulation walls
- Price: around 65 euros
Neudorff Duo Therm
- 530 liters volume
- With lid and bottom grid
- Price: around 90 euros
Ing. G. Beckmann Thermokomposter
- 800 liters content
- Made entirely from recycled plastic.
- Hexagonal shape hides the size.
- Price: around 140 euros
Conclusion
Quick composters offer an excellent opportunity to banish the ugly compost heap from sight in the small garden. At the same time, they quickly produce rich humus and free fertilizer. A thermal composter made of insulated material also increases the efficiency of the nutrient cycle through higher temperatures inside. Both models are commercially available, but with a little manual skill you can build them yourself. This not only saves money, but also increases flexibility in terms of size and area of application. In this way, even in the smallest garden, the beneficial use of rich compost is within reach.
