|Compost Tumblers - Comparing compost tumbler models|
• Compost tumblers and compost bins, how they differ
• Benefits and limitations of compost tumblers
• Comparing different compost tumbler models
• Composter tips and FAQs
• Where to buy a compost tumbler
|Compost tumblers spare the gardener one of the most arduous tasks in composting - ‘turning’ the compost pile. This is usually done with a pitchfork in open compost bins and compost piles where there is room to wield the tool. Turning the pile is done to speed up the composting process by providing aeration and by mixing the hot composting material with materials recently added, as this introduces microbial activity to help break down the fresh materials.|
|What is a compost tumbler|
|A compost tumbler is a fully sealed container which can be rotated to mix the composting materials. The sealed container also helps contain the heat generated by the composting process, thereby speeding the process of converting kitchen and yard waste into compost. Compost tumblers were invented to make composting simpler and faster.
Compost tumblers are not the same as compost bins. Compost bins are designed to be set on the ground, and most compost bins have open bottoms. While compost bins are the least expensive kind of composter, they have several disadvantages: it is difficult to get a pitchfork inside to turn the compost, heat is easily dissipated which slows the composting process, and rodents can easily burrow under the sides to gain access to the composting materials.
|Benefits and limitations of compost tumblers|
• speeds up the composting process - you can convert waste to finished compost in as little as 3 weeks in a sealed compost tumbler, under ideal conditions. Outdoor temperature, time of year, and the correct balance of carbon and nitrogen matter are factors which influence the speed of composting. In colder, wet climates,, it will take considerably longer than 3 weeks to complete the composting process.
• keeps rodents, raccoons, pets out of compost
• eliminates composting odors
• tidy, attractive, suitable for urban and suburban residential properties
• more expensive than compost bins - tumbler-style composters are usually built of thicker materials to hold wet, heavy composting materials. This is not an issue with bin-style composters because the bins are open-bottomed and do not need to support any weight. Tumbler-style composters also have support legs or bases with rollers which make them more expensive to manufacture.
• over 9.5 cu ft capacity units can be hard to turn - most tumbler-style composters are designed for capacities of 9.5 cubic feet or less. This is because a bigger drum is harder to spin when it's full. Larger capacity spinning composters are available, however, which utilize a mechanical aid for turning the drum. The AutoFlow 400, for example, uses a rod and gear system to turn a drum with a large 15 cu ft capacity.
|Different models of compost tumblers: comparisons, pros & cons|
|With the popularity of gardening and the trend in home vegetable gardening, new designs are available with various features to improve the composting process and experience. Here is a review of the basic designs.|
|Sealed drum compost tumblers:|
Pros: simple design, fewer parts
Cons: slower to compost than aerated models
|The basic compost tumbler is a drum or barrel which is either mounted on a raised axle for spinning, or set on a base with rollers which facilitate spinning. The drum must include some feature which will 'flip' the composting materials as the drum turns. Without this, the materials would simply slosh from side to side without actually turning and mixing, even as the drum rotates. These models usually have indented slots which provide a hand-hold for turning, and on the inside of the drum these appear as raised ridges which flip the materials as the drum turns.
Models which are set on a base with rollers have the advantage of being able to roll the drum off the base, so the drum can be rolled to wherever you want to empty the compost. In some models, the base also serves as a 'compost tea' maker, by collecting liquid drain-off from composting materials. The tea can be used as a liquid or spray fertilizer. Models which are raised enable the gardener to place a wheelbarrow or bucket directly under the drum so that finished compost is easily transferred for moving to the garden beds.
|'Aerated' drum compost tumblers:|
Examples: UCT9, EZ Compost Wizard
Pros: aeration speeds the composting process
Cons: aerating spikes or core can reduce access for larger clippings
|'Aerated' composters are designed to deliver air directly into the composting materials. This has the advantage of speeding the composting process, which enables gardeners to cycle more batches through their composter. It also enables you to get by with a smaller composter since the through-put is faster. Different models have different designs for providing enhanced aeration.|
|The UCT9, pictured above and right, uses a central core which draws air from below the drum and distributes it through the interior. The core also serves as a paddle, to help break up the materials as the drum is rotated.
Other models use hollow 'spikes' radiating inward to provide central aeration. These spikes also break up the materials as the drum spins. Larger clippings may get stuck between spikes. For this type of composter, be sure to chop up any long clippings or plant skeletons before adding them to the drum.
|Dual-bin compost tumblers:|
Examples: Jora JK 125, JK 270
Pros: speeds composting process; easy to access finished compost
Cons: more expensive than single bin models
|The dual bin design takes a different approach to the continuous-use composter concept, Two bins are set side-by-side into a single rotating drum. Although each bin is a little smaller than other model composters, the thickly insulated compartments conserve the heat generating by the decaying matter, and this greatly speeds the process. The sides have screened openings which provide aeration to each chamber.|
|Older models of dual-bin compost tumblers had a single door covering both chambers. Newer models have separate doors for each chamber. This is an improvement because you can rotate the drum directly over a wheelbarrow or bucket, and tip the finished compost in.
The quality of the door hinges is important in this design. One brand (which we do not sell) has cheap hinges which compromises the functionality.
Some larger models of dual-chamber composter tumblers have a gear-driven crank handle to facilitate turning the drum.
|Compost tumbler tips and FAQs|
|Here below are the most commonly asked questions regarding compost tumblers and some tips from our experience:|
|How big a composter should I buy?
The 7.5 cubic foot models are practical for a family of four. If your family is larger, or if you have a small garden or yard, then the 9.5 cu ft model will be more suitable. For large families, schools, restaurants or people with vegetable gardens or big lawns, the larger models such as the 12 cubic foot EZ Compost Wizard ( a tumbler) or the 15 cubic foot Aerobin ( a standing bin) are appropriate.
Some composters are vertically mounted on the axle, while other are horizontally mounted. Which is better?
The axis is the center of spin, and composters which have the materials closer to the center axis (horizontally mounted) are easier to spin. However, composters which have the materials further from the central axis (like the UCT9 or the Tumbleweed) may be harder to spin when full, but the contents are better mixed when the drum is rotated. Both designs work, it is up to user preference.
Should I set my composter in the direct sunlight?
It seems logical that by locating your composter in direct sunlight, the materials inside will be warmer and this will speed the composting process. However, this is not necessarily the best advice. If your composter is made of plastic, even thick-walled heavy duty composters such as the UCT9, we recommend locating it in shade or partial sunlight. This is because the hot sun can distort the plastic to where the lid may not screw on easily, if at all. Also, some people have noted that the color of the plastic may become faded or blotchy after prolonged exposure to direct sunlight. If you are using your composter properly, with a fairly balanced mix of carbon and nitrogen, the sealed unit will generate enough heat for effective composting.
How often should I spin my compost tumbler?
About three or four spins a week is adequate. We give our tumbler a spin or two each time we take our kitchen compost keeper out to be emptied in the composter. This is usually about twice a week.
My compost tumbler is too heavy to spin.
Be sure to set your composter on level, solid ground. Blocks or patio stones may be used if necessary. The tumbler will spin easier when the axis is horizontal and the weight is evenly distributed. Older gardeners, and people with limited strength may find turning a full composter difficult. In these cases, we suggest only filling the composter 2/3 and then letting the batch finish.
Should I add water to my compost?
In most cases, no. Compost should be moist but not wet. There is usually enough moisture in kitchen scraps and yard clippings, and adding water may cool and slow the composting process. Although some gardeners may want to get compost 'tea' to use as a liquid fertilizer, adding water may not be the best choice. See our comments below regarding compost tea. If you live in a vey dry environment, adding some water may be helpful, but take care to add only enough water to moisten the contents.
My compost is a wet, soggy mess and doesn’t seem to be composting.
This is a very common condition, especially during winter in colder regions of the country. The secret to a healthy compost pile is to maintain a working balance between carbon-rich and nitrogen-rich materials. (See our Composting page for more information.) In winter, we keep adding food scraps and other moist nitrogen-rich materials, but dry leaves and other dry materials are not as readily available. Mixing in dry carbon-rich materials will help restore a wet compost pile.
To learn more, read our article How to fix a soggy compost pile.
How can I add fresh materials when waiting for a batch to finish.
Once your composter is as full as you want it to be, i.e. full to the point where it is still easy to spin, you will want to stop adding fresh materials until the current batch is done and the finished compost can be emptied. This may a period of two to three weeks. During this time, fresh materials for the compost can be stored in a garbage can or similar container. This is not an issue with dual-bin or cantinuous composters.
Do I need to use a compost starter?
Compost starters are helpful to kick-start the process, but they are not necessary. Leave a little bit of finished or semi-finished compost in the bin as a "starter" for the next load. You can also add some garden soil into the composter to start the process going.
Some composters have a base which collects 'compost tea'. Is this useful?
Liquid drippings from the composting materials can be collected and used as a fertilizer, and some tumbler models have incorporated a feature to collect this 'tea'. However, since the tea basin is at the bottom, close to the ground, it can be difficult to get a bucket under the spigot. These models need to be blocked up higher, or have a short hose attached to the spigot. Another way to collect compost tea is to simply shovel some compost into a bucket and fill with water, then cover and let sit for a few days.
|Where to find compost tumblers|
|The best place to buy compost tumblers is online. This is because local stores which may sell compost tumblers can only afford to keep one or two models in stock. And staff at these stores may have limited or no experience with composting, and therefore unable to give you advice.
Online sources, such as Eartheasy, carry a wide range of compost tumblers. Also, because we have actual experience using these composters, we only stock models which will give good results for the consumer. Our family has been composting for over 30 years, and we have tried everything from open piles, to compost bins, compost tumblers, large bins such as the Aerobin, and very large ‘farm-style’ compost pens.
The cost of shipping is a factor in buying online, and this is partly offset by no taxes added to the purchase. Some composters are offered with free shipping, which is ideal if you are in the market for a new composter.