The substrate is definable as the base or substance that a vegetable needs to live and grow, to which it is fixed, from which it draws its nourishment.
It is considered, for a whole series of factors that we will describe later, a different material for quality, nature and appearance from the simple earth, and is intended primarily for cultivation in containers or pots in which the plant will be sown and cured before being transplanted into real soil. The substrate it must necessarily fully satisfy certain particular needs for the balanced growth of plants, such as for example a greater quantity of air, water and nutrients than would be obtained with cultivation in open vegetable gardens.
CHOICE OF SUBSTRATE
Cultivated in pots, both vegetables and fruit plants have a space that is certainly smaller than in the open field. For this reason, care must be taken to ensure that the composition of the substrate respond in detail to their needs.
In fact, most vegetables need a soil rich in nutritive elements, of medium texture (not too loose, but not too compact). Furthermore it must be particularly capable of retaining water while allowing too much water to flow out. The composition of the earth, ideal for plants and vegetables, must be rather soft, soft and aerated, so as to allow a good penetration of oxygen into the roots while remaining compact enough to maintain the stability of the stem.
One of the most common substrates sold in garden shops or "do it yourself" is known as "universal soil". The universal soil has the property of retaining water and humidity in general very well, contains a rather considerable amount of nutrients and is well suited to the cultivation of most common vegetables.
But everyone can have their own particular needs, and in this case some practical advice may be useful to those who want to try their hand at preparing a great DIY and personalized substrate.
A DIY SUBSTRATE
First of all it is necessary to procure fertile garden soil (garden shops sell it in bags of different weighings and characteristics). The fertile garden soil contains a fair amount of clay that makes it stable and compact, effectively helping it with moisture retention.
Then you need good compost. Compost is a substance that is obtained from the decomposition of organic materials and has the function of lightening the soil by improving its quality by adding nutrients. The compost can be created by itself in different ways and with different techniques, or it can be purchased with the characteristics that seem to us most suitable (we still recommend the one prepared exclusively with vegetable waste because it is better suited to our purposes).
In addition to compost, we need complete organic fertilizer (the absolute best is horse manure, but the bovine manure will be equally good)
Finally it is very useful to get some coarse sand.
Perfect: now that we have all the elements, creating the DIY substrate will be a breeze!
Mix together three parts of fertile garden soil, two parts of compost and one of that coarse sand you got yourself. Make the appropriate proportions, but know that every 10 l of soil should be added 30 g of complete organic fertilizer.
Mix all the mixture you have made and let it air carefully. Finally, before pouring it in, you will need to moisten it slightly with a watering.
Naturally this "recipe" is calibrated on standard needs that can and must be modified according to individual needs and individual expectations. In fact, there are several other very useful ingredients if you want to vary the usual composition of the substrate: among these we find peat and expanded clay.
Peat makes the soil porous and light, able to absorb moisture well. However, unlike compost, it is not very nutritious. Before mixing it with your soil it is good to moisten it and crumble it.
Expanded clay improves soil oxygenation and makes it more porous. It is found in granular form and is ideal for cultivations destined for very large pots, because - if used instead of sand - it significantly reduces the overall weight.
Other variations to our "recipe" may become necessary in some cases. For example, if we want to set up a cultivation of aromatic plants, we will prepare different mixtures to the one described above by adding a greater quantity of sand because, as is known, this type of plant prefers a drier, leaner and well-drained soil.
Another mixture will also be necessary for fruit plants, whose bulky and heavy stems require a decidedly more vigorous and compact substrate. In this case we will not have to do anything but add higher quantities of fertile garden soil to the standard composition.
Finally, another very useful type of soil is that used specifically for sowing. It is a soil that by its very nature must necessarily satisfy certain special needs: in addition to having to guarantee the sprouting of the seeds, it will necessarily have to support the development of young plants that will be born precisely from the seeds themselves, bringing them the right and proper nourishment, helping them in the early stages , of course, the most delicate of their growth.