Composting continues even in the winter, although it happens at a reduced rate. Bacteria can survive at very low temperatures, and they keep digesting matter even when the compost pile is covered in snow. To help the bacteria work a little longer in the fall and start working earlier in the spring, it is a good idea to insulate outdoor compost bins with carpeting or old blankets and tarps. Simply cover the bin, and if it has open sides, surround it with your chosen insulator. You can also surround and cover outdoor compost piles with bales of straw or hay. The more heat the pile can retain, the longer and more vigorously it will work throughout the winter. Cover the bin when the outdoor temperatures cool down, or whenever it is convenient for you.
Winter Worm Bins?
It is possible to winterize worm bins, and some composters have even had success with worm windrows. A windrow is any row of vegetation that has been heaped up as if by the wind, but a person can also create a windrow on purpose. One such person is Bentley Christie, owner of the website Red Worm Composting (www.redwormcomposting.com).
Starting in late fall 2009, Christie built a large worm windrow in his backyard in Ontario, Canada. He used rotted pumpkin waste, grass clippings, horse manure, a large amount of leaves, and rotted straw. He then covered the whole thing with a large tarp to keep the heat in. A short while later, he pushed aside the top layer of leaves and straw and added most of the contents of an outdoor worm bin, including the worms. At this point (early December), the protected windrow had an internal temperature of about 68 degrees. After a snowfall, the temperature in the windrow went down, so he added more rotted straw (with worms) and a large amount of coffee grounds.
About a month later, the pile had cooled to a disappointing 39 degrees, and the top layer had frozen. Armed with food scraps and coffee grounds that had been warmed to room temperature by bringing them for several days, Christie pulled the windrow apart and inserted a string of rope lights that are commonly used to decorate decks. He then added shredded cardboard, hay, coffee grounds, more hay, and then the warmed food scraps. He watered the bin, added some Bokashi microbes, and then covered the whole thing with a blanket before replacing the tarp. The later addition of a little molasses and some water, as well as a hot water bottle, warmed the windrow up, and a couple of days later the temperature was back above 60 degrees.
By the end of January, the windrow had mostly started to warm up again, and Christie added some horse manure, fresh straw, more water, and more molasses. Additions of food waste, leaves, and grass helped increase the temperature even more, and by the end of February, the temperature was between 77 and 86 degrees. He found red worms and springtails in the pile and fed it again with alfalfa and molasses water. Springtails are tiny insects, usually only 1 to 2 millimeters long, but sometimes up to 6 millimeters, or about a ¼ inch, that spring or jump when disturbed. They eat plants, pollen, and other small particles and are usually beneficial to a worm bin.
To read about all the ups and downs of Christie’s winter composting with worms, check out the links at the bottom of this blog post: www.redwormcomposting.com/winter-composting/winter-worm-windrow%E2%80%9302-22-10/. As you can see, winter composting is possible; it just takes a lot of work and a large amount of ingredients.
A warm, healthy bin will steam as the weather cools in the fall, but there is little chance of overheating your compost. Temperatures up to 150 degrees are desirable in your compost, and it is unlikely the bin will get hotter than that in the late fall and winter in most parts of the United States. If you are concerned about overheating the pile, check the temperature of your pile on a warm day and if necessary, uncover it, and turn or stir it to let it cool down. If using a plastic tarp, remember to remove it when the weather begins to warm up in the spring so that you do not overheat the pile or cause moisture build up. Monitoring the pile with a remote sensor thermometer or taking frequent readings with a probe thermometer are good ways to stay aware of the state of your compost. This will allow you to make additions to it throughout the winter, assuming you can get to it through the snow, and will let you know when it is “waking up” in the spring.
Indoor Composting
Indoor composting is ideal all year round if you live in an apartment or condominium with a small yard, or if you do not generate enough waste to feed a large compost pile. It is also good for people who only need a small amount of compost to use in window boxes or container gardens, and it is a good alternative for people who normally keep an outdoor bin, but cannot access it in the winter. Indoor composting means that all the food scraps from winter holiday feasts will be composted instead of sent to the landfill, and you can keep generating compost even when the weather is bad. There are several products on the market for indoor composting, including small countertop or under counter systems and larger indoor bins. Even vermicomposting can be done indoors if you have a room where you can control the temperature.
Pros and cons of indoor composting
To determine if indoor composting is right for you, check out this list of pros and cons.
Pros
• You do not need a yard or garden.
• You do not have to do a lot of physical labor.
• You do not need a lot of space.
• Some indoor composting systems can consume meat, small bones, and other waste that you generally cannot put into an outdoor system.
• It may be less expensive than maintaining an outdoor system.
• You do not have to worry about attracting animals to your property.
• You do not have to worry about the concerns of neighbors.
Cons
• Depending on the system you choose, it may be more expensive than maintaining a low-tech outdoor system.
• Indoor composting takes up some space.
• It may cause foul odors if not properly maintained.
• It may attract flies if not properly maintained.
• If you do not have a yard, container gardens, or houseplants, you will have to find a way to dispose of the compost.
If the pros outweigh the cons for you, then go ahead and start indoor composting. Following are some ways you can begin composting inside.
Indoor trash bag composting
The easiest way to compost indoors is in a simple trash bag. This will produce an anaerobic compost mixture that smells quite bad when first opened. Remember that aerobic composting uses a lot of oxygen and, therefore, does not have the same rank smell as anaerobic composting. After the compost is fully decomposed, you will have to rake it out onto the soil to dry to eliminate most of the smell. After it has dried for three or four days, you will be able to use the compost as normal.
Supplies and Tools
• Sturdy 32-gallon trash bag
Instructions
1. Keep the bag inside in a warm place, such as a heated garage. If it gets cold or freezes, it will not produce compost. You definitely do not want to keep this inside your house because of the noxious smell produced by anaerobic decomposition. If you do not have a garage to keep it in, do this kind of composting only in warm weather.
2. Fill the bag with a combination of leaves, food scraps, grass clippings, finished compost, if you have it, and an activator such as alfalfa meal.
3. Close the bag and shake it daily to mix the contents. Water it if the contents dry out. Add dry grass clippings and leaves if the contents are too wet.
4. When the bag is full, hold your breath, and dump it on the ground. Rake the compost out on the ground and expose it to the air for three to four days to dry out before using it as you would any other compost.
If your compost is ready before spring, leave it bagged up. You definitely do not want to try to dry it out indoors. This is a good project for an early spring day when there is a nice breeze blowing. The breeze will help dry the compost quickly and will blow the smell away.
Commercial Indoor Compost Bins
There are a wide variety of indoor compost systems. These range in size from very small home systems to large commercial systems used in restaurants and other environments that generate a lot of waste. Choosing the system that is right for you depends on the space you have available, the cost of the system, and how much composting you would like to do. This section discusses several commercially available systems that can be used inside. Sources for these systems are listed in the Appendix.
Non-electric indoor systems
Non-electric systems use a variety of methods to decompose the scraps put into them. Some use fermentation, usually with the assistance of added microorganisms. These systems convert the carbohydrates in the scraps into alcohols, carbon dioxide, or organic acids. For comparison, think of the way yeast ferments when you are baking bread. It consumes the flour and creates carbon dioxide bubbles in the dough. If you let bread dough rise for too long, it will take on an unpleasant sour taste and smell from the alcohols the fermentation process releases. Fermenting compost systems will also have that sour smell because they are anaerobic systems. Most of these systems will be air-tight and enclosed, so there will only be a smell if you open it during the fermentation process.
Non-electric systems also include worm bins used in vermicomposting, which is a non-electric (although not anaerobic) process.
Effective Microorganism Bokashi Compost System
EM™ Bokashi systems are a type of anaerobic system used extensively in Asia. More than three million Korean households use this composting method. The system consists of four buckets, two lids, and EM™ Bokashi mix, which is a blend of bran and so-called “Effective Microorganisms™,” including lactic acid bacteria, yeast, photosynthetic bacteria, filamentous fungi, and actinomycetes that cause the compost to ferment. The Bokashi mix can be purchased separately and used in other brands of kitchen composters.
In the original Bokashi system, two of the buckets have holes drilled in the bottom, and the other two are solid. To start composting, place one drilled bucket inside a solid bucket and place your kitchen waste inside the top bucket. You can include any scraps, cooked or raw, and can even include animal products. Sprinkle the scraps with the Bokashi mix to cover them and compress the mixture by hand to squeeze out any liquid into the bottom bucket. Replace the lid and make sure it is attached tightly to prevent oxygen from entering the compost and to prevent odors from seeping out.
After you fill the first set of buckets, begin using the second set. By the time the second set is full, the contents of the first set are usually ready to be buried in the ground or added to an outdoor compost heap. By this time, the meat products will have broken down enough to be added to the outdoor heap without attracting pests. You can dilute the liquid from the bottom bucket and use it as a compost tea to water plants. Some types of kitchen composters come with a tap on the side so you can drain off the water as needed.
Electric systems
There are several brands of electric-powered compost systems on the market. This kind of system uses an electric motor to stir the compost and uses heating elements to warm the compost. Because the compost is artificially heated, this kind of system can usually consume products that you cannot put in outdoor systems, such as meat, small bones, and animal waste.
NatureMill, Inc., (www.naturemill.com) makes a sleek and modern-looking indoor composter that can handle up to 120 pounds of waste per month. This composter currently retails for $299 to $399, depending on the model you choose. It is 20 inches high by 20 inches deep by 1 foot wide and can fit easily into a kitchen cabinet. It can also be used outdoors in a sheltered location where the electrical connection is safe from the elements. The NatureMill composter heats and stirs the compost internally and has a container in the bottom that catches the finished compost as it is made. To use it, the manufacturer recommends purchasing a “booster mix” of microorganisms and coir bricks, which are bricks of coconut fibers. These are mixed with the compost to provide a carbon source. This type of composter can handle meat, fish, and dairy scraps and can also compost pet waste and kitty litter.
GreenGood® (www.greengood.com) makes an indoor “in-vessel” composter. The residential version of the machine can accept slightly more than 4 pounds of food waste each day. It heats the waste and mixes it with bacteria-laden sawdust. After it ferments, the bulk of the waste is reduced by 95 percent. The gases generated by the bacteria are filtered and the resulting water and carbon dioxide by-products are released through a tube to the outdoors. The microbes in this kind of system are extremely hearty and can tolerate acidic and neutral environments (0 to 8 on the pH scale). They can tolerate up to 19 percent salinity and can decompose fish, meat, poultry bones, and animal waste. The company also makes larger composters for use by restaurants, schools, hotels, and even remote islands. The home version was not available for sale in stores at the time of this writing, but interested individuals may contact Sara Estep, GreenGood’s business development director, at 704-784-0012, for ordering information.
The selection of systems discussed in this chapter should provide an idea of the wide range of available composting options. One of them could be the tool you need to help you start composting and making wonderful soil amendments for your plants.
Case Study
Sara Estep
Amateur composter
Concord, North Carolina
Business Development Director
I have been composting for a couple of months using an in-vessel compost system manufactured by Green Good®. The machine is quite clean and efficient with minimal odors, but sometimes there are items that are not fully composted, and I have to filter them out.
I use the finished compost on my lawn and garden. I enjoy knowing that I have diverted pounds of food waste from the landfill and turned it into nutrients and vitamins for my lawn that are natural for our planet.
My son is 4 years old, and he loves the thought of recycling and composting. He does not completely understand yet the concept of doing it, but loves to be my helper. This is a motivation for me to do it because it inspires him so much.