Composting is nothing more than another word for decomposition. In real terms it may be more accurate to say “assisted” decomposition. For in the natural world, all things decompose without any help from man. A tree that dies in the forest will eventually turn to compost, it may take decades, maybe even centuries. But eventually, everything turns into worm food.
Where the art of composting comes in is actually accelerating the process, and thus creating a useful garden product in a timely manner. Just as we can cut up and chip the remains of that dead tree and speed up the process from decades to years, we can take many types of material and by combining them in the proper proportions, adding water, air and perhaps beneficial “bugs” (e.g. earthworms, beneficial bacteria, etc.) we can create a finished compost in as little as a month.
Everything eventually decomposes, but not everything is suitable for our gardens. Stay away from meat, bones and any part of an animal. The possible exception being fish, but the smell and attractiveness to vermin may outweigh it’s desirability to use in the compost pile. Let’s look at some common compost materials.
There are two types of manures, animal and plant. (also commonly called green manure ) Most people think of animal poop when they hear the term manure, but in garden terms it can also mean a crop, usually high in nitrogen content, grown for adding fertility to the garden. Animal manure is a valuable addition to the garden, with proper care. As a general rule, no manure should be used from any carnivorous or meat eating animal. Dog and cat poop is a no-no. Manure is often too hot to add directly to the garden. What this means is the nitrogen level may cause sensitive plants to burn. Adding manures to compost will actually cause the pile to heat up, that is, to literally get hot! This aids in the rapid decomposition of materials and increases the biological activity. This heat gets the pile off to a great start and once it cools, the biological activity continues adding not only fertility to the garden, but valuable microorganisms, as well as the much loved earthworms.
- Horse ~ Good old road apples. Fairly readily available, most stables will be glad to let you haul it away. If you find a good source be advised, it is like a good fishing hole. Keep it to yourself lest you show up to get a load and find your source has already been cleaned out.
- Cow ~ Most likely you will find cow manure, composted & bagged and sold at your favorite retailer. This form is usually OK to add directly to the garden. It probably won’t add much to your compost pile. If you have fresh cow manure available to you, you should compost it first as cow manure can be pretty hot.
- Chicken/Poultry ~ A very good source of ammonia since chickens (and all birds) excrete their urine mixed with their solid waste. You can find pelleted chicken manure, (Black Hen is one brand from the Black Cow people) which is an excellent fertilizer as well as compost component.
- Rabbit ~ Nice natural pellets. Makes a superb addition to compost.
- Other ~ There are many other animals who can contribute to the compost pile, litter from most rodents, hamsters, gerbils, guinea pigs, make great compost. Goats have pelleted manure like rabbits, only larger. Again, the rule of thumb is, if the animal eats meat, don’t use it’s manure in the garden.
Many of you may be concerned about the fragrance manures carry. It is true, some manures have strong, unpleasant odors. Poultry manure in particular can be unpleasant. (to us anyway, your dog may find it absolutely irresistible! ) Many others, however will find some manures have an earthy smell that is not at all unpleasant. In any event, the composting process will leave all ingredients fairly odorless.
- Clover ~ This is probably the best known green manure, or cover crop. It is a legume, which means it takes nitrogen from the air and “fixes” it to the soil. This is a very advantageous group of plants for green manure.
- Alfalfa~ Another legume, this can either be grown as a cover crop, or bought in a bale and added to the compost pile.
- Beans/Peas/Peanuts ~ These can all be grown as cover crops, to be turned in or harvested and added to the compost pile.
- Timothy & Alfalfa ~ Commonly sold by the bale as T&A, this is not nearly as “hot” as alfalfa alone. It can be composted by itself for a wonderful compost or used to mulch your beds to add nutrients and compost as it breaks down.
Green manures are usually used a couple of ways; either harvested for hay and added to the compost pile or as a cover crop and turned in to add organic matter to the soil directly. We will discuss different composting methods a little later.
OTHER COMPOST MATERIALS
Just about anything that once grew can be used in the compost pile. If you have something with a lot of seeds, you will especially want to create a hot pile to kill the seeds. Some of the more common materials for compost are;
- Leaves ~ Earthworms love ’em! You can usually find bags set out to the curb, but with giant cans designed for easy curbside collection being introduced to most areas, it is more and more difficult to find bagged leaves. Leaves can be composted alone for something called leafmold. Leafmold is a light, fluffy compost that can be added directly to the garden.
- Grass Clippings ~ Again, a once plentiful material that has become somewhat scarce. It used to be thought that grass clippings should be collected (usually to end up in the landfill) but nowadays we let them stay on the lawn where they compost and help maintain the fertility of the lawn. Golf courses still collect clippings, but their abundant use of chemicals could contaminate the garden. If you can find grass clippings, they are still one of the best materials for compost.
- Pine Needles ~ Easy to come by, they can be bought in bale form called pinestraw. They are thought to be capable of acidifying soils with a high pH, but this effect is probably minimal. Still they can be a valuable addition to the compost pile and they really add an attractive mulch to any garden.
- Wood Chips ~ High in cellulose, and usually very low in nitrogen, wood chips decompose very slowly even in the hottest pile. This limits their usefulness in the vegetable garden, but they can be used to mulch paths and if used sparingly, to aerate the garden soil.
- Garden Waste ~ By all means, we should be recycling all our garden waste back into the garden. Depending on the type of plant, it can either be added as is or may benefit from chopping into smaller pieces.
LET’S MAKE COMPOST!
There are several ways to make compost, the easiest way is to simply let nature take it’s course. However, it is possible to speed the process up considerably and that is what we will discuss here.
- Sheet Composting ~ Very simple method to create compost, and useful when beds or portions of the garden are allowed to lay fallow. You will find it a good practice to mulch your fallow garden deeply with hay, leaves, grass clippings or any other suitable material. Continue to replace the mulch as weeds attempt to grow and by the end of the dormant season you will find your garden weed free and ready to plant! Other methods of sheet composting can be acheived in the same way. Spread a layer or layers of whatever compost material you have at hand and let it rot. You can cover the compost with hay, newspapers, cardboard, etc. to keep weeds from taking over. You can also layer it like a horizontal version of a compost pile. (see below) You can use this method to turn a lawn area into garden beds by smothering the grass with a layer of mulch, which eventually turns into finished compost. As I grow older, I am always looking for ways to lessen the harder, physical labor end of gardening. This is an easier way to compost, but it will take a bit longer.
- Tumblers ~ There are many commercially available compost tumblers around, and they work real well for smaller amounts of compost. Their main attractions are their easy use and the ability to constantly add new materials and still have a steady supply of usable compost. This makes them ideal for composting things like kitchen scraps and garden waste which is generated on a fairly regular basis. The basic concept is you have a drum with an opening for adding new material and removing finished compost, mounted on a stand of some sort which allows you to crank and turn the drum. They work fairly fast, but again, you are limited by the amount of materials you can fit in the drum. A very good choice for people with limited space, or any gardener who wishes to recycle as much of their reusable waste as possible.
- Bins ~ This category covers a wide range. Everything from a five gallon bucket stashed under the sink for kitchen scraps to large multiple bin affairs constructed from concrete block or wood. Let’s address the smaller versions here and we’ll get to the larger ones below. Many gardeners find themselves hating to “throw out” any waste that might be suitable for turning into black gold for the garden. This list includes everything from kitchen scraps to newspapers and cardboard. One good way to utilize these scraps and keep them from entering the waste stream, is to keep a little bin handy. The actual bin is limited only by your imagination and the materials you may have at hand. A five gallon bucket, with a few air-holes drilled into it will work fine, as will an old whiskey barrel half. Boxes, trashcans and wire bins all work as well. The main thing to successfully processing these things into compost will be our little friends, the earthworms. You can buy them, or dig them yourself. Either way, they will most likely become self perpetuating as long as you provide them with some simple needs. You will need to have a mix of materials in the bin. Shredded newspaper is a good base material, as would be leaves, hay or most any dry, organic material. Stay away from manures as they could generate enough heat to kill or drive away your worms. Fill your bin with the dry material, moisten it slightly, it shouldn’t be soggy, and add your worms. They should proceed to burrow out of site, where they will remain. You can now add any manner of waste, kitchen scraps, more newspaper, cardboard, etc. Stay away from glossy paper though as it may contain chemicals not beneficial to worms. You will want your medium to stay “fluffy” so the worms can easily churn their way through turning your trash to the garden gold known as worm castings. Keep your bin from drying out and usually a shady spot is better than a sunny one, but if you need to locate it in the sun, just make sure to keep a thick blanket of mulch on top. Some people find it handy to have a small door or slot installed somewhere to allow removal of finished castings while others simply allow the worms to finish one batch and then start another. You would dump, dig or otherwise remove the contents, setting aside a small batch to start the new one. Every gardener should have a worm bin.
- The Pile ~ There are few things in life that I like better than turning a compost pile and seeing the steam rise from it’s interior. Yes, I am that much of a garden geek. The method of composting most people are familiar with is the simple heap or pile. It is the best way to produce large amounts of compost in a relatively short period of time. It also requires the most physical effort. And, I might add, this is where the gardener’s art really comes into play. For as mentioned earlier, no matter what, everything will decompose into compost eventually. But to put together a pile that will really cook and become usable compost in as little as a month, well, that takes a little bit of know-how.
- Location ~ First, site your pile in an area where you have enough room to turn it. That is assuming you want a fast turnaround. If not, then you can easily skip a lot of this section. For a slow pile, you can pretty much just throw together whatever materials you have, add some water and walk away for a year or so. You will still be rewarded with a pile of beautiful compost. It really is that easy. However, for a quick turnaround, you will need to be a bit more diligent in your building and maintaining of your pile. This is where some people like to build somewhat elaborate bins. It really isn’t necessary to contain your compost pile in a bin, but it can help to manage it and give you a quick turnaround. A simple wire bin will do, you can use concrete remesh wire for a sturdy bin, or a lighter mesh wire with a wood frame. These types of bins are probably more suited for the long term natural composting though, since turning the pile is an important part of the quick method. Another common bin setup is a 3 wall bin made from wood or cement block. Many people will construct a 3 bin setup which works very well to turn your piles and keep a constant turnaround of finished compost. I prefer the free standing pile myself, since it affords a great deal of flexibility. However you choose to manage your pile(s), the methods will be the same.
- Layers ~ In order to facilitate the transformation of separate materials into the gardener’s gold we know as compost, we need to proportion our different materials so they work together to quickly process. Without getting technical, what we are looking for here is heat. Heat will be produced by certain materials and not others. In general materials high in nitrogen will heat up the pile. This group includes all the manures as well as grass clippings. We want to mix a smaller proportion of these heat producing materials to a larger volume of other materials. A ratio of perhaps 3-4:1 is probably about right. This will vary greatly depending on the “hotness” of the material. Horse manure for instance, may already be fairly well composted when you get it. But if it is not, the fresh manure will be hotter than the composted stuff. This is where experience and maybe some intuition come into play. The worst case scenario is a slower cooking pile, so we have a lot of latitude here. I will say that my favorite for a quick, hot pile is baled alfalfa. It will really fire up a pile to the point where you can’t hold your hand in the interior for more than 30 seconds or so. Once you have decided on the actual proportions, you just build it like a layer cake. For demonstration purposes, I will use oak leaves as the cooler material and alfalfa hay as the heat producer. You will want to add a thick layer of the leaves and water them till evenly moist. Then add a smaller layer of the alfalfa and water it as well. I usually like to puncture the layers with my pitchfork to allow water and air to freely move between the layers. Repeat until the pile is at a manageable height, 5′ is high enough to allow for a good cooking, yet not so high you can’t manage it. I like to add additional holes through the pile by taking a length of rebar (any long rod will do) and driving it into various places in the pile and wiggling it to make some nice, deep holes. This allows for good air/water penetration throughout the pile. It also gives me access to the interior of the pile to monitor it’s heat. (just stick your hand in and see how hot it is) Using alfalfa hay, my piles heat up within hours and reach an almost too hot to touch temperature.
- Turning ~ I like to let them sit and cook like that for 2 weeks or so. More or less time may be required depending on the weather. When I sense just a bit of cooling, I turn the pile. This time the object is to mix the layers and even out any inconsistencies of moisture in the pile. This turning will cause the pile to heat up again and after another week or two it will really start to cool. For faster compost an extra turning can be done during this period. When the pile really starts to cool and stay cool, we will start to see the worms move in. This is when the pile will really start to become a single consistency of rich, black, crumbly compost. It can be used as soon as it has cooled even though the consistency is still fairly course, especially as a top dressing. But for a nice planting bed, I prefer to let it break down for another couple of weeks or more till the worms have churned it into a finer consistency. The 3 bin method simply gives us an organized space to take the pile from phase to phase. We build our pile in the first bin, turn it the first time into the middle bin and optionally start a new pile in the first. Then of course we repeat the process turning the pile into the last bin. This just adds a bit of organization to the garden which is never a bad thing.
Compost is the heart of the vegetable garden, but it really should be a part of our ornamental gardens as well. We don’t have to go to the great lengths to make compost before adding it to ornamentals, sheet composting works well enough for our other planting beds. I like to use a rich mulch, made commercially from shredded plant waste. This type of mulch is available from many municipalities as well. I have been able to build up my native soil to a rich, black, earthworm laden compost with only regular mulching. All plants enjoy the benefits of compost. We have all heard that the Amazon rain forest only contains an inch of topsoil. The part that is left out is that inch is a constantly renewed layer of compost. The forest uses what it needs and returns it to the forest floor. We can do much by recycling all our gardens waste as well as adding additional organic matter from other sources. By providing our gardens with a rich smorgasbord of nutrients to choose from, rather than limiting them with a specialized chemical diet, we not only promote healthy, lush gardens, we lower the amount of potential contamination of our water sources.
- Vegetable Garden ~ In the vegetable garden we can use our compost as raised planting beds. This avoids many of the problems we encounter in our indigenous soils such as root knot nematodes. Compost can be laid directly on top of the native soil to a height of a foot or so without any need to build sides. It can withstand our typical heavy seasonal rains for a season or more. Plenty of time to get a crop or two in. After that, you only need supplement with an additional layer of compost. A layer of hay for mulch will also help your beds stand. Of course you can build beds out of wood or other materials, but you lose a lot of flexibility. I like to change the layout of my garden regularly.
- Ornamental Gardens ~ As mentioned above, we shouldn’t deprive our ornamental plants of the benefits of compost. Locally, Forestry Resources sells a product called Vita-Mulch. It is derived from plant waste that is shredded and added to other mulches and ingredients. It is a rich, dark brown color and gives the garden a nice natural look. Compost imparts the same benefits to the ornamental garden as it does the vegetable garden. By virtue of adding large amounts of organic matter to the soil, the root knot nematode population decreases. Just one of many benefits.
- Fruit Trees ~ Fruit trees tend to have somewhat higher water/nutrient requirements. It is easier to meet those requirements by adding a nice thick layer of compost at their base. You can even custom tailor the compost for specific needs. Adding epsom salts, wood ash, etc.
- Palms ~ Palms really benefit from the use of a heavily organic mulch. Much like fruit trees, many palms have specific nutrient needs that our native soils don’t provide. The abundance of trace elements found in good compost help prevent a host of problems many palms suffer from.