All those who own a garden, even a small one, know well how many 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 crops, should instead be spent to give the ecological islands, or bins, sacks and bags of cut grass, branches, leaves, and maybe even vegetables or fruits too ripe, or extirpated to make room for other crops.
Composting allows us to use these wastes, which become raw materials, to produce a fair amount of excellent humus soil; in this way the time spent for the "cleaning" of our garden can reward us, even offering us 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, 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 soil rich in minerals, excellent for our crops.
First of all it is necessary to choose the type of composter more suited to our purposes; therefore it is the case to evaluate both the time that we usually dedicate to the green of our house, and the quantity of waste that our garden usually produces.
The mound: if our garden is large we will have the possibility to build a composting mound, or a small area, possibly rectangular, bounded by a fine mesh or a lattice. It is advisable to cover the compost heap with sheets of non-woven fabric, or jute, to avoid the direct incidence of the sun's rays, and also to limit the amount of water due to rain.
Composter: it is a bell, often in plastic, equipped with an upper opening, for the insertion of the material to be composted, and a lateral opening, or a gate, to pick up 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 little, or if we want to carry out composting in a small space, we can use bins, or boxes, properly drilled, to allow better ventilation, and with a lid.
In any case it is good that the composting containers are bottomless, 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 to compost that accelerate the decomposition. They should also be fitted with a lid, so that the rain does not affect the contents. To accelerate the decomposition is also better to grind 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, when decomposed, produces heat; at the center of the mass of organic material the temperature can reach 60 ° C.
Position: in order to better compost large quantities of material we must follow some precautions, in order not to risk that our composter is filled with rotting and malodorous material.
To avoid that our compost gets too hot or dry, it is advisable to place the composter in a semi-shaded place, possibly in an area covered by the branches of a caducifolia plant: in this way we will also avoid the possibility that in winter the compost cools too much .
Aeration: in order for bacteria and microorganisms to propagate in our waste it is good that the presence of oxygen is high, otherwise in their place too many anaerobic bacteria, typical of rot, would be produced which produce in our compost bad odor and toxic compounds; for this reason 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 good practice to mix the most wet waste, such as grass, with more dry ones, 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 composting mass with a pitchfork; if, however, we should notice a rapid compaction, at least in the first weeks, it is better to make ventilation holes in the compost by means of a stick.
Humidity: for the correct proliferation of bacteria in the compost the right degree of humidity is necessary; It is therefore good to guarantee a good presence of water, by watering the material inserted in the composter, or by guaranteeing a good quantity of wet material, such as grass or fruit and vegetable cleaning waste. In a dry compost and in a compost of water the bacteria die and our composting fails.
To ascertain the right degree of compost moisture, it is sufficient to hold a handful of material to compost, this should only moisten the palm of our hand; if it drips, we will hasten to insert dry material, such as sawdust, into the composter, but if it appears to us to be free of moisture it is good to water it, or introduce strips of damp paper.
Carbon / Nitrogen ratio: to ensure a good decomposition it is good to remember that bacteria proliferate better in a very rich substrate of Carbon, present in wood, straw and paper; It is however necessary the right nitrogen content, 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 take care to mix the largest number of waste materials, avoiding the preponderance of one over the others.
Enzymes: to ensure that the decomposition takes place in the best ways we can also add commercially available enzymes in the composter, which accelerate compost maturation, improving bacteria "digestion" and eliminating any unpleasant odors at the same time.
If we have little space, but we want to try our hand at composting, we can do it even 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, reminding us to stay very long pay attention to humidity, but also not to introduce weed or sick plant seeds, to avoid then spreading diseases and seeds with our compost.
We can also make use 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 some earth; place the container in a shady place and they will help us to decompose the organic material, generating an excellent humus for our vessels.
Types of composter
Materials that can be inserted into a composter
- Branches and leaves, properly shredded.
- Grass, possibly dry, to prevent the material from being compacted too much in the composter.
- Egg shells, possibly minced, so that they are decomposed more easily.
- Leftovers of cooked food; It is good to add them in small quantities, to prevent them from attracting mice or flies.
- Fruit and vegetable leftovers, skins, waste.
- Dried flowers.
- Weeds pulled out of the garden; to avoid that the seeds remain alive in the compost it is good to insert them at the center of the mass to be composted, so that they reach the highest temperatures.
- Funds for coffee and tea
- Card, possibly not printed.
- Wood ash, in small quantities.
- Pine needles, reminding us that they lower the ph of the compost.
Material not to be put into the composter
- Any type of plastic material.
- Coal ash.
- Tetrapak containers.
- Printed paper, although sometimes some newspaper may be useful.
- Aluminum and metals in general.
- Bones; the time needed to decompose is too high.
- 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, reminding us to stir the new material once in a while.
The soil that we will obtain is fertile and smells of undergrowth (if it is smelly something has gone wrong in composting!), We can use it as a fertilizer for garden plants, for pots, in the holes of new plants to be planted. If we are particularly hurried we can start using 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 we prefer it is good to sift it, with a fairly large mesh screen, so as to avoid distributing pieces of wood or lumps of compost that are not perfectly decomposed for our garden.