All Year Gardening Composting
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Are you afraid that compost is a smelly, unpleasant, or difficult process?
Do you know what happens when things rot?
A compost pile is a fast-track method of changing organic materials into something delicious resembling soil, called humus.
Compost making is a simple process.
Done correctly, composting becomes a natural part of your all year gardening activities, just like pruning or mowing the lawn. And, making compost does not have to take any more effort than bagging up yard waste.
Handling well-made compost is always a pleasant experience. There is no similarity between the good-smelling brown or black crumbly substance dug out of a compost pile and the manure, garbage, leaves, grass clippings and other waste products from which it began.
As raw organic materials are eaten and re-eaten by many, many tiny organisms from bacteria (the smallest) to earthworms (the largest), their components are gradually altered and recombined.
Gardeners often use the terms organic matter, compost, and humus as interchangeable however there are important differences to be explained.
Organic matter is formed by growing plants.
The organic matter from both land and sea plants fuels the entire chain of life from worms to whales. Rich earth abounds with single cell organisms like bacteria, to microscopic round worms called nematodes, snails and slugs (many so tiny the gardener has no idea they are populating the soil).
Humus is a special and very important type of decomposed organic matter.
Most important, humus is the last stage in the decomposition of organic matter. It is a very complex mixture that varies according to the type of organic matter that decayed, and the environmental conditions and specific organisms that made the humus.
Whatever its varied chemistry, all hummus is brown or black, has a fine, crumbly texture, is very light-weight when dry, and smells like fresh earth.
It is sponge-like, holding several times its weight in water. Like clay, humus attracts plant nutrients like a magnet, so they aren’t so easily washed away by rain or irrigation. Then humus feeds nutrients back to plants.
Composting accelerates the decomposition of organic matter into humus.
What in nature might take years composting can make happen in weeks or months. But compost that seems ready to work into soil may not have quite yet become humus. Though brown and crumbly and good-smelling and well decomposed, it may only have partially rotted.
When tilled into the soil at that point, compost doesn’t act at once like powerful fertilizer and won’t immediately contribute to plant growth until it has decomposed further. But if composting is allowed to proceed until virtually all of the organic matter has changed into humus it will be far more useful, safer and healthier than chemical fertilizer.
All Year Gardening Composting – Making Compost 101
Think of composting like making other fermented foods like kombucha, bread, beer, or sauerkraut. But composting for plant food is much less demanding.
There are easy ways and more complex ways of composting.
I want you to see how easy it can be to make perfectly usable compost.
At this point, I could recommend cookbook composting recipes a small backyard recipe, the fast recipe, the apartment recipe, the wintertime recipe, the making compost when you can’t make a pile recipes.
First, we’ll explore the principles behind composting. Understanding of basics will enable you to make your own to suit your situation.
Composting Basics – Making Humus
The mix of the composting ingredients is important to get the right Carbon/Nitrogen ratio.
As a rule of thumb, Carbon waste = straw, hay, autumn leaves, paper, sawdust, teabags.
C: N ratio’s
The other component needed is Nitrogen waste – anything green such as green leaves, fruits, vegetables, coffee granules, seaweed, lawn clippings.
As a rule, these are fresh and usually moist.
Fruit & Vegetables 1: 20
Lawn Clippings 1:20
Garden Waste/Weeds 1:30
Coffee Granules 1:20
Leaves are handy as all gardens have bushes, plants, and trees that are deciduous, these will naturally form a carbon waste source. Whether they are autumn or green leaves, its good to shred them with a shredder or lawn mower by running over them a few times.
Micro organisms and worms need the right mix of Carbon and Nitrogen sources to survive and create the humus by eating, digesting and excreting the organic material several times over to make humus.
For the happiest creatures in your compost pile, a C/N ratio of 25 to 30 parts Carbon to 1 part Nitrogen is needed.
If the C: N ratio is too high (excess Carbon), decomposition slows down. If the C: N ratio is too low (excess Nitrogen) you will end up with a stinky pile.
A mixture of organic materials is needed.
Imagine trying to make compost from just a heap of pure, moist sawdust.
Very little and very slowly.
You could wait five years for compost to form from pure moist sawdust and still not much would happen.
Mixing the sawdust with other materials having a very low C/N, then it would decompose, along with the other items.
To make compost rot rapidly, you need to achieve a strong and lasting rise in temperature.
Cold piles will eventually decompose, and humus will eventually form but, without heat, the process can take a long, long time.
Getting a pile to heat up promptly and stay hot requires the right mixture of materials and a sensible handling of the pile’s air and moisture supply.
Keeping Compost Critters Happy
Under good conditions, with a relatively unlimited food supply, bacteria, yeasts, and fungi can double their numbers every twenty to thirty minutes, increasing geometrically: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1,024, 2,048, 4,096, etc. In only four hours one cell multiplies to over four thousand. In three more hours, there will be two million.
For food, they consume the compost heap. Almost all oxygen-breathing organisms make energy by “burning” some form of organic matter as fuel much like gasoline powers an automobile.
No engine is one hundred percent efficient. All motors give off waste heat as they run. Similarly, no plant or animal is capable of using every bit of energy released from their food and consequently radiate heat. When working hard, living things give off more heat; when resting, less. Even single-celled animals like bacteria and fungi breathe oxygen and give off heat.
When a large quantity of decomposing materials are heaped up, biological heat is trapped within the pile and temperature increases, further accelerating the rate of decomposition.
By the time that temperature has increased to about 50 degrees F, the chemistry of most living things is beginning to operate efficiently.
A composting thermometer is a great help unless you have a good idea of heat using your hands. Personally, I think a composting thermometer is a nice idea as it’s tricky to measure heat through gloves and messy without them.
Compost piles can get remarkably hot. The most heat tolerant soil animals will die or exit a compost pile by the time the temperature exceeds 120 degrees, leaving the material in the sole possession of microorganisms. Most microorganisms cannot withstand temperatures much over 130 degrees. When the core of a pile heats beyond this point, they either form spores while waiting for things to cool off, or die off.
Plenty of living organisms will still be waiting in the cooler outer layers of the heap to reoccupy the core once things cool down.
How hot the pile can get depends on how well the composter controls some factors.
You should expect the heaps you build to exceed 140 degrees and shouldn’t be surprised if they approach 150 degree
Canada’s Office of Urban Agriculture has published a simple recipe to follow; their Steps are one of the best descriptions found from hours of research to make composting easy for you.
Canada’s Office of Urban Agriculture City Farmer’s Composting Recipe
In a rodent resistant bin, create a base of 3″ – 4″ or woody, brushy material to promote aeration (do not mix into the pile).
Alternate layers of green and brown materials; keep the layers 2″ – 4″ deep. Common green (nitrogen) materials are grass, food scraps (uncooked fruit and vegetables, coffee grounds, filters, tea bags and egg shells) (wet), garden trimmings. Common brown (carbon) materials are fall leaves, straw and newspaper strips (dry). Chop up larger materials for faster decomposition.
Whenever you add a food scrap layer, make sure you sprinkle it with soil and then cap off with a brown layer to prevent smells and flies.
Mix bin contents often (minimum once every two weeks). This introduces air and gets bin heating up again. Mix older materials with newer materials for faster decomposition.
The moisture content in the bin should be like a wrung out dish rag. Only add water if the pile is very dry after mixing.
The pile will shrink. Continue to add and mix until the bin is almost full. Place carpet on the surface of the pile to retain heat and moisture.
Compost is ready to use when it looks like humus (after about two to three months). However, aging the compost for another 1 to 2 months is recommended.
More COMPOSTING considerations for perfect All Year Gardening Composting
Compost Particle size
Microorganisms are not capable of chewing or mechanically attacking food. Their primary method of eating is to secrete digestive enzymes that break down and then dissolve organic matter.
Since digestive enzymes attack only outside surfaces, the greater the surface area the composting materials present, the more rapidly microorganisms multiply to consume the food supply. And the more heat is created.
All desirable organisms of decomposition are oxygen breathers or “aerobes. There must be an adequate movement of air through the pile to supply their needs. If air supply is choked off, aerobic microorganisms die off and are replaced by anaerobic organisms.
With insufficient oxygen, foul-smelling materials are created. Instead of humus being formed, black, tarlike substances develop that are much less useful in the soil. Under airless conditions, much nitrate is permanently lost.
Heaps built with significant amounts of coarse, strong, irregular materials tend to retain large pore spaces, encourage airflow and remain aerobic. Heat generated in a pile causes hot air in the pile’s center to rise and exit the pile by convection. This automatically draws in a supply of fresh, cool air.
But heaps made exclusively of large particles not only present little surface area to microorganisms, but they also permit so much airflow that they are rapidly cooled.
This is one reason piles made of finely ground or soft, wet materials such as lawn clippings tend to compact, ending convective air exchanges and bringing aerobic decomposition to a halt. In the center of an airless heap, anaerobic organisms immediately take over.
Composters use several strategies to maintain airflow.
- Blend an assortment of components if different sizes to create air pockets,
- Turn the pile, tearing it apart with a fork and restacking it, will reestablish a looser texture and temporarily recharge the pore spaces with fresh air,
- Construct the base layer of fine sticks, smaller tree prunings, and dry brushy material. This porous base tends to enhance the inflow of air from beneath the pile. One powerful aeration technique is to build the pile atop a low platform made of slats or strong hardware cloth.
- Create air channels. As the pile is being constructed, vertical heavy wooden fence posts, 4x 4’s, or large-diameter plastic pipes with numerous quarter-inch holes drilled in them are spaced every three or four feet.
Once the pile has been formed and begins to heat, the wooden posts are wiggled around and then lifted out, making a slightly conical airway from top to bottom. Perforated plastic vent pipes can be left in a heap. With the help of these airways, no part of the pile is more than a couple of feet from oxygen
A dry pile is a cold pile. Microorganisms live in thin films of water that adhere to organic matter whereas fungi only grow in humid conditions. If the pile becomes dry, both bacteria and fungi die off. The upwelling of heated air exiting the pile tends to rapidly dehydrate the compost heap.
It usually is necessary to periodically add water to a hot working heap. Unfortunately, remoistening a pile is not always simple. The nature of the materials tends to cause water to be shed and run off much like a thatched roof protects a cottage.
Since piles tend to compact and dry out at the same time, when they are turned they can simultaneously be rehydrated. When you fork over a heap take brief breaks and spray water over the new pile, layer by layer. Two or three such turnings and waterings will result in finished compost.
The other extreme a pile too wet can turn the pile into a chilled, airless mass. Cover your heap with old plastic sheeting during the rainy season when it is also cold.
How to know your moisture content is OK
Understanding how much moisture to put into a pile soon becomes
intuitive. Beginners can gauge moisture content by squeezing a handful of material very hard. It should feel very damp but only a few drops of moisture should be extractable.
When building a pile, keep in mind that certain materials like fresh grass clippings and vegetable trimmings already contain close to 90 percent moisture while dry components such as sawdust and straw may contain only 10percent and resist absorbing water at that. But, by thoroughly mixing wet and dry materials the overall moisture content will quickly equalize.
Size of the pile.
It is much harder to keep a small object hot than a large one. That’s because the ratio of surface area to volume goes down as volume goes up.
It is difficult to make a pile heat up that is less than three feet high and three feet in diameter. And a tiny pile like that one tends to heat only for a short time and then cool off rapidly. Larger piles tend to heat much faster and remain hot long enough to allow significant decomposition to occur. Most composters consider a four-foot cube to be a minimum practical size.
At home, the practical limit is probably a heap six or seven feet wide at the base, initially about five feet high (it will rapidly slump a foot or so once heating begins), and as long as one has material.
Though we might like to make large compost piles, we rarely have enough materials on hand to build a heap all at once. A single lawn mowing doesn’t supply that many clippings; your kitchen compost bucket only amounts to a few buckets a week. Garden weeds have collected a wheelbarrow at a time. Leaves are seasonal. So almost inevitably, you will be building a heap gradually.
It is far more sensible to learn from experience. Gauge the proportions of materials going into a heap by the result. If the pile gets hot and stays that way for a few weeks before gradually cooling down then the C/N was more or less right.
If, after several turnings and reheating, the material has not thoroughly decomposed, then the initial C/N was probably too high. The words “thoroughly decomposed” mean here that there are no recognizable traces of the original materials in a heap and the compost is dark brown to black, crumbly, sweet smelling and most importantly, _when worked into the soil it provokes a marked growth response, similar to fertilizer.
If the pile did not initially heat very much or the heating stage was very brief, then the pile probably lacked nitrogen. The solution for a nitrogen-deficient pile is to turn it, simultaneously blending in more nutrient-rich materials and probably a bit of water too.
After a few piles have been made you will begin to get the same feel for their materials as bakers have for their flour, shortening, and yeast.
It is also possible to err on the opposite end of the scale and make a pile of too much nitrogen. This heap will heat very rapidly, become as hot as the microbial population can tolerate, lose moisture very quickly, and probably smell of ammonia, indicating that valuable fixed nitrogen is escaping into the atmosphere. When proteins decompose, their nitrogen content is normally released as ammonia gas. Most people have smelled small piles of spring grass clippings doing this very thing. Ammonia is always created when proteins decompose in any heap at any C/N. But a properly made compost pile does not permit this valuable nitrogen source to escape.
It is very important to ensure that about 10 percent of a compost pile is soil and to coat the outside of a pile with a frosting of rich earth that is kept damp.A very hot pile leaking ammonia may contain too little soil, but more likely it is also so hot that the nitrifying bacteria have been killed off. Escaping ammonia is not only an offensive nuisance; valuable fertility is being lost into the atmosphere.
Weather and season.
You can adopt some strategies to keep the weather from chilling a compost pile. Wind both lowers temperature and dries out a pile, so if at all possible, make compost in a sheltered location. Heavy, cold rains can chill and waterlog a pile.
Composting under a roof will also keep hot sun from baking moisture out of a pile in summer. Using bins or other compost structures can hold in heat that might otherwise be lost from the sides of unprotected heaps.
It is much easier to maintain a high core temperature when the weather is warm. It may not be so easy to make hot compost heaps during a northern winter. So in some parts of the country, I would not expect too much from a compost pile made from the autumn cleanup.
This stack of leaves and frost-bitten garden plants may have to await the spring thaw, then to be mixed with potent spring grass clippings and other nitrogenous materials to heat up and complete the composting process. What to do with kitchen garbage during winter in the frozen North makes an interesting problem and leads serious recyclers to vermicompost. More on this later
In southern regions, the heap may be prevented from overheating by making it smaller or not as tall.