Everyone who owns a garden, even a small one, knows how much green "waste" it produces, especially if it is flanked by a small vegetable garden. And they also know how much of the time they would devote to the care of the crops, must instead be spent to give to the ecological islands, or to the bins, sacks and sacks of cut grass, branches, leaves, and maybe even of vegetables or overripe fruit, or uprooted. to make way for other crops.
Composting allows us to use these waste, which become raw materials, to produce a fair amount of excellent humiferous soil; in this way the time taken for the "cleaning" of our garden will be able to reward us, also offering us some good fertilizer for our garden and our vegetable garden.
In fact, the proper storage and treatment of branches, leaves, grass, food scraps, fruit and vegetable peels, allows bacteria, microorganisms and small insects to eat them, to develop and to decompose the organic substances present in our waste; after a few months the organic material thus treated will become a mass of microorganisms and nutrients, called compost, similar to the humus that we can find in the undergrowth: a soft, well-aerated and mineral-rich soil, excellent for our crops.
First of all you need to choose the type of composter best suited to our purposes; therefore it is appropriate to evaluate both the time we usually dedicate to the green of our home, and the amount of waste that our garden usually produces.
The heap: if our garden is large we will have the possibility of constituting a heap for composting, or a small area, possibly rectangular, bounded by a fine mesh net or a trellis. It is advisable to cover the compost pile with sheets of non-woven fabric, or jute, to avoid the direct incidence of the sun's rays, and also to limit the supply of water due to rain.
Composter: it is a bell, often in plastic, with an upper opening, for the insertion of the material to be composted, and a side opening, or a gate, to collect the mature compost or to control the composting trend. Some types of composter they are distributed by the municipalities, which also guarantee, to those who use them, a discount on waste disposal rates.
Bins: if the material we want to compost is not enough, or if we want to compost in a confined space, we can use bins, or boxes, suitably perforated, to allow better ventilation, and equipped with a lid.
In any case it is good that the composting containers have no bottom, or with the bottom consisting of a grate, and that they are placed in contact with the ground: in this way earthworms and other insects will migrate from the soil of our garden into the compost which accelerate its decomposition. They should also be fitted with a lid so that rain does not alter the contents. To speed up decomposition, it is also better to shred the material you want to compost, so that it is more easily digested by bacteria and insects.
"Hot" means the composting of a large quantity of waste material, at least one cubic meter, which, by decomposing, produces heat; in the center of the mass of organic material the temperature can reach 60 ° C.
Position: to best compost large quantities of material we must follow some precautions, so as not to risk that our composter becomes filled with rotting and smelly material.
To prevent our compost from overheating or drying out, it is advisable to place the composter in a semi-shaded place, possibly in an area covered by the branches of a deciduous plant: in this way we will also obviate the possibility that the compost becomes too cold in winter. .
Aeration: for bacteria and microorganisms to propagate in our waste, it is good that the presence of oxygen is high, otherwise too many anaerobic bacteria, typical of rotting, would be produced in their place, which produce bad odor and toxic compounds in our compost; for this it is advisable that the first layer of the heap, or the bottom of the container, is made up of coarsely chopped branches and leaves, so that the compost remains raised from the ground. It is also a good idea to mix wetter waste, such as grass, with other drier waste, so that the material in the composter does not compact too quickly, preventing air from circulating freely.
To improve the aeration and mixing of the material inserted in the composter, it is advisable to intervene periodically, at least 2-3 times in the first two months, moving and turning the compost mass with a pitchfork; if, however, we should notice a rapid composting, at least in the first weeks, it is better to make aeration holes in the compost using a stick.
Humidity: the right degree of humidity is required for the correct proliferation of bacteria in the compost; it is therefore advisable to ensure a good presence of water, by watering the material inserted in the composter, or by ensuring a good quantity of moist material, such as grass or waste from cleaning fruit and vegetables. In dry compost and in water-soaked compost, bacteria die and our composting fails.
To ensure the right degree of humidity in the compost, it is sufficient to hold a handful of material to be composted, this should only moisten the palm of our hand; if it drips we will hurry to insert dry material into the composter, for example sawdust, if instead it appears to be devoid of humidity it is good to water it, or introduce moistened strips of paper.
Carbon / Nitrogen Ratio: to ensure good decomposition it is good to remember that bacteria proliferate better in a substrate very rich in Carbon, present in wood, straw, paper; however, the right nitrogen content is necessary, present for example in kitchen waste, which must be present in a much smaller quantity than carbon.
The best way to be sure of maintaining the right Carbon / Nitrogen ratio is to be careful to mix as many waste materials as possible, avoiding the preponderance of one over the other.
Enzymes: to ensure that decomposition takes place in the best possible way we can also add enzymes, available on the market, to the composter, which accelerate the maturation of the compost, improving its "digestion" by bacteria and at the same time eliminating any unpleasant odors.
If we have little space, but we want to try our hand at composting, we can also do it on a balcony or in the cellar, in small containers, cold composting will take place, for which it is useful to follow all the precautions of the hot one, remembering to stay a lot be careful about humidity, but also not to introduce weed or sick plant seeds, to avoid spreading diseases and seeds with our compost.
We can also avail ourselves of the precious help of earthworms: it is sufficient to place them in a well-ventilated and covered container, with moistened sheets of paper, kitchen scraps and a little earth; place the container in a shady place and they will help us to decompose the organic material, generating an excellent humus for our pots.
Types of composters
Materials that can be inserted into a composter
- Branches and leaves, suitably shredded.
- Grass, possibly dry, to prevent it from compacting the material in the composter too much.
- Egg shells, possibly chopped, so that they are decomposed more easily.
- Cooked food leftovers; it is good to add them in small quantities, to avoid them attracting mice or flies.
- Fruit and vegetable leftovers, peels, scraps.
- Dried flowers.
- Weeds uprooted from the garden; to avoid that the seeds remain alive in the compost it is good to insert them in the center of the mass to be composted, so that they reach the highest temperatures.
- Make coffee and tea.
- Paper, possibly not printed.
- Wood ash, in small quantities.
- Pine needles, reminding us that they lower the ph of compost.
Material not to be placed in the composter
- Any type of plastic material.
- Coal ash.
- Tetrapak containers.
- Printed paper, although sometimes some newspaper can be useful.
- Aluminum and metals in general.
- Bones; the time needed to decompose them is too long.
- Synthetic or dyed fabrics.
Composting: How to use the composter
After 6-9 months our compost is ripe and can be used by removing it from the side of the container, which we will continue to fill, remembering to stir the new material from time to time.
The soil we will get is fertile and smells of undergrowth (if it is smelly something went wrong in the composting!), We can use it as fertilizer for garden plants, for pots, in the holes of the new plants to be planted. If we are particularly hasty, we can start using the compost when it is still fresh, after 2-3 months, even if its quality is certainly lower than that of mature compost.
Before using the compost for the purpose that we prefer, it is good to sift it, with a fairly large mesh sieve, in order to avoid distributing pieces of wood or lumps of compost not yet perfectly decomposed for our garden.