Compost. All you need to know

Composting is subjecting organic matter to a transformation process to obtain natural fertilizer, compost... This transformation can be carried out using a composter, without any type of mechanism, any motor or any type of maintenance expense.

The daily garbage bag generated contains 40% organic matter that can be recycled and returned to the earth in the form of humus for plants and crops. We must know that for every 100 kg of organic waste, 30 kg of free fertilizer is obtained.

In this way, we contribute to the reduction of the volume and weight of waste taken to landfills and incinerators, with the consequent environmental improvement. At the same time, it is possible to reduce the consumption of chemical fertilizers that burn plants and contaminate wells and aquifers.

01. The cycle of life

Nature shows us that it organizes its life cycle and restores its growth, for example: when in the forest, in autumn, the leaves of the trees fall to the ground, along with pieces of branches, animal excrement or grasses. , they go to a phase of decomposition in which many elements intervene that cooperate in this process

The sun, water, heat, cold and different living species (larvae, worms, snails, fungi, a multitude of insects...), which transform everything into humus, that dark-colored earth with a characteristic earthy smell. good and spongy texture. Thus, humus contributes to the continuity of the life cycle by feeding plant species that, in turn, will feed animal species.

02. Organic remains

"Matter is neither created nor destroyed, it only transforms" Impossible things cannot be asked of the earth if the life cycle is broken. The remains of pruning, harvesting or vegetables in general, which currently end up in landfills or incinerators, must be returned to the earth, duly transformed into humus.

03. Alternative to synthetic fertilizers

The fertilizer obtained from the composting process allows the use of chemical fertilizers to be reduced, which not only contaminate aquifers due to excess nitrates, but also contaminate during the production, packaging and transportation process.

04. Why a composter?

It is evident that compost can be made outside of a composter, as it has always been done in manure heaps, but the most common thing is not to have as much land as other systems, such as piles or composting plants, need. In a composter it will be more sheltered from inclement weather (sun, rain, wind) and will not dry out or become humid, therefore, it will not be necessary to pay too much special attention or dedication.

In addition, no water will be wasted to water it when it is dry. Visually it will not cause any impact to the most reluctant family members to see so many organisms in constant activity.

The composter can be installed anywhere, without disturbing the neighbors. Important: It must be taken into account that this organic matter can also be one of the main causes of contamination if the transformation is incorrect. It should not be considered as waste, but as a very valuable resource.

05. Industrial composting

Needless to say, it does a great service to large cities, where it is more difficult to do home composting due to lack of space and the need for large-scale treatment to manage the volume of organic waste generated. In this way, the resulting compost can later be used in parks and gardens in the same cities. But it must be clarified that the best option is always home composting, because tons of organic matter does not have to be transported to the industrial plant.

Industrial composting requires energy to operate, while composting at home does not. The level of impurities in compost is around 10% in an industrial plant, while what is made at home is exactly the transformation of what has been deposited.

06. What is needed?

A recycled and recyclable plastic composter. A tool for removing compost, as appropriate, of a size consistent with the dimensions of the composter. Some pruning shears to cut small branches that are added as structuring material. A shovel to extract mature compost.

Optional: A sieve to separate the coarser remains from the finer compost. A wood chipper if, when pruning, you obtain a number of thick branches that cannot be cut with scissors.

07. The best location of the composter

Always in direct contact with the earth and, for convenience, make it a place close to the kitchen.

Care must be taken that it does not receive too much sunlight so that you never have to water it. If it is placed in the shade, the better. Between 50 cm and 1 meter are needed on the sides to be able to extract the mature compost comfortably.

08. Once the composter is installed, the most important thing will be the mixture of materials.

From this moment you can start composting, an activity that you will never want to abandon as it becomes a very rewarding free time activity.

The remains that are deposited should always be mixed; You should not make layers of fresh and wet materials or layers of dry materials, that is, everything must always be well mixed. This does not mean that it is necessary to mix the remains daily, but only when a significant amount of the same material is deposited in the composter, such as cut grass, or a large amount of dry leaves.

If small amounts of organic matter are added every day, it is enough to mix the remains of the composter once a week.

09. What can be composted. From the kitchen. Of the garden

- Remains of fruit and vegetables. Green or dried flowers, leaves and plants
- Crushed egg shells
- Grass
- Expired yogurts and fruit juices
- Crushed pruning remains
- Cork stoppers and kitchen paper
- Ashes and natural wood sawdust
- Oil and vinegar for dressing
- Remains of harvest from the garden
- Coffee grounds and remains of infusions
- Farm animal manure and straw

10. What cannot be composted.

- Fish, meat and bones, until you are used to the composting process (odors)
- Diseased plants or fruits and/or large quantities of rotten vegetables
- Manure from domestic animals or humans (pathogens)
- Ashes or sawdust from treated wood or agglomerates (glues, varnishes)
- The result of sweeping (heavy metals)
- Obviously, any material that is not organic or biodegradable

11. Possible problems and solutions

The following information will allow you to avoid any type of discomfort, although there should not be any problem.

Problem, meaning, solution

- Ammonia smell.

There is too much grass not mixed with dry leaves

Mix and stir

- Rotten smell.

The compost is too wet and there is little oxygen

Mix with dry matter and stir

- The matter is dry and cold

Moisture is needed

Mix with dry matter and stir

- There are many fruit flies

They are doing their job, they are no problem

If you want to hide them or see them in less quantity, you have to bury the kitchen remains a little between the dry leaves.

12. The compost has already matured

If you want to know if the compost is mature, you should take a handful in your hands and smell the forest smell, see that it is a black or dark brown earth, which stains your hands very little because it is not very humid, that nothing that had been deposited in the composter is recognized, except branches, pine cones and fruit stones that will be separated in the sieve and returned to the composter so that they continue their process and serve as a structuring agent again.

The temperature will be that of the environment due to the lack of activity of the microorganisms found in the most recent remains.

13. How to use compost

Gardens and crops need compost to renew the substances that plants and other vegetables have absorbed during growth.

To apply it to ornamental plants and trees, a mature compost must be used (between 4 and 6 months) to ensure slow and continued absorption of nutrients as it rains or is watered.

If what you want is to apply it to the garden, use fresh compost (between 2 to 3 months) since the release of nutrients will be much faster but shorter.

The plants do not burn even if the recommended amount is exceeded; Since this compost does not contain chemicals, there is no danger of this. In any case, below we explain some examples of the correct use of compost in different areas:

- In the garden: between 1 and 2 months before planting anything and with the compost mature. About 4 liters of compost are applied per square meter (approximately, 4 liters are 1 kg)

- Fruit trees: Once all the season's harvesting has been done, about 5 l/m2 is applied to the tree (a layer of 2 cm), to return what it has produced in the form of fruit.

- Lawn: When mowing begins periodically, that is, in spring, the mature compost is passed through the sieve so as not to hinder the growth of the grass and 1 l/m2 is applied if it is for top dressing, and 5 l/m2 if It's for a new garden.

- Ornamental trees: In autumn, to compensate for the effort made in spring and summer, about 2 cm is applied to the entire surface occupied by the crown.

- Plants and flowers: In Spring, about 2 cm of compost is needed to show themselves in all their splendor and demonstrate what they are capable of year after year.

- Transplants: Plants whose location, soil, light, etc. have been changed should always be favored. Compost not only gives them the nutrients they need to develop properly, but also keeps them healthy. In these cases, 1 part of compost must be mixed with 3 parts of soil.


01. Does composting produce bad odors?

Quite the opposite. The decomposition process of plant remains gives off a characteristic and pleasant smell. Remember the smell that the humid forest makes. This happens because the thousands or millions of organisms that feed on the remains that are deposited in the composter do not allow more time to pass than necessary to transform them into compost.

If any other type of odor is noticed, see section 11. Problems and solutions.

Important: Do not make layers of wet or dry remains, always mix everything well.

02. How long will it take to collect compost?

It will always depend on the amount of plant remains, but as a general rule, from the first day you start depositing remains until you collect compost for the first time, between 3 and 4 months will pass.

You know that the compost is mature because it has a dark brown color, it gives off a smell of forest soil, and you cannot recognize the remains from a couple of months ago, since they will have been transformed during the composting process.

03. Is it necessary to add any products?

No, nature does not need anything that it cannot provide itself. If appropriate, you can add a biological composting accelerator to reduce the time from 4 months to 2. Kitchen scraps greatly accelerate the decomposition of garden waste, so they must be mixed well.

04. Can composting attract or generate nuisance animals?

If the remains are mixed (once a week), annoying insects such as fruit flies will not appear. In any case, these organisms will also help form the compost and, in any case, their presence will always be limited to the interior of the composter.

If ants appear, this will indicate that it has not been mixed enough and that they have spent weeks building the nest. The solution will be to stir well. Slugs or other organisms that previously ate the plants will now leave them aside to go to the composter, they will serve to eat the remains and not the garden flowers. Animals, such as dogs, cats or mice, cannot enter the composter, since it is a closed container, designed to prevent them from entering.

05. Is it necessary to water it?

It is almost never necessary to water the compost if we have the composter in the shade or semi-shade.

Depending on the dry or humid climate, it can be moistened, but in moderation. Normally the water contained in all vegetables is enough to maintain the necessary humidity. When in the past, composting was done on the ground or between four pieces of wood, water was wasted to maintain the humidity necessary for the life of the organisms that carry out the process. One of the advantages of composters is that, thanks to their thick walls, they maintain constant temperature and humidity all year round. It is observed how the heat given off by the process condenses on the lid of the composter and falls back inside in the form of water.

If you add a considerable amount of dry leaves, they can be moistened a little, but it is always better to mix them with kitchen scraps so that they absorb moisture.

06. Is it necessary to add soil?

No soil should be added since the weight of the soil would be a problem for the correct circulation of oxygen within the composter.

What is important is to collect 100% fertilizer and not a mixture of fertilizer and soil. In the past, layers of soil were placed when surface composting was done, to avoid drawing the attention of rodents and domestic animals to the food remains that were deposited, something that does not happen inside composters.

07. Is energy necessary to operate?

The main advantage of this recycling system lies precisely in the fact that it does not require energy to operate, since it does not have any mechanism. There are no maintenance costs and the composters are specially designed and built to be outdoors.

08. How and when to use the sieve?

The sieve is used to separate the finer compost from the thicker parts, such as branches, pine cones, etc. The most practical thing is to collect all the compost 3 or 4 times a year, but you can always collect small quantities by only opening the lower doors.

The day the composter has to be emptied is a special day. It is very fun to have different family members or friends participate in this task.


The remains of the upper part that have not yet been disposed of are separated. It is decided how and where the fine compost and the undisposed remains are separated. Every 3 or 4 shovelfuls that you pour over the sieve, you must use your hand with a glove to ensure that only the finished and finest compost passes through the holes.

If you want, before this operation, you can let it dry for a day, this way it will filter better, but surely, when you empty the composter you are so eager to obtain the precious material, that you will not want to wait even a few hours. Furthermore, when it is a little humid, the smell of the forest is so pleasant that it more than compensates for spending a little more time sifting.

The remains that have been separated at the beginning are put back into the composter, along with the thicker parts that have remained on the other side of the sieve. This will be when you can wet the remains, which will surely be dry because no more kitchen remains have entered. There is no need to worry about the organisms that appear scattered on the ground since they will find their way to the composter themselves and continue working.

09. Should there be an adequate proportion of the remains that are deposited in the composter?

First, keep in mind that no measures are necessary. What matters is that the composter is capable of recycling what the family produces.

Now, if what you want is to get close to perfection to obtain a balanced and quality compost, it is advisable to mix three parts of wet remains rich in green nitrogen (kitchen scraps, green leaves, freshly cut grass, garden plants or garden, etc.) with a part of dry remains rich in brown carbon (dry leaves, straw, sawdust, crushed branches, pine cones, etc.).

10. Is the compost obtained suitable for all types of plants?

Indeed, due to the fact that it is a completely natural product, it can be applied to any plant, whether indoor or outdoor, garden, orchard, fruit trees, flower beds, flower beds, lawns, etc. It is a universal product and the plant to which it is applied will surely appreciate it.

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