Soils and substrates for growing seedlings

Mid and late February is a hot season for gardeners, it's time to start growing seedlings. At this time, the seeds of some flower crops, as well as nightshade crops (pepper, eggplant, late varieties and tomato hybrids) are sown, the development time of which until the moment of planting in the ground is 65-70 days. Earlier crops and varieties do not need to be sown in February - the seedlings will stretch out strongly due to lack of light and outgrow, which will lead to a decrease in yield. And in March-April, the seedling conveyor was already launched at full capacity ...

Every year, the gardener faces the problem of choosing a soil for seedlings. Today's abundance of soils on the market can really confuse a person. After all, according to the most conservative estimates, there are at least a hundred companies (both domestic and foreign) producing various soils. Of course, not all of them are presented in stores, for the most part there are products of about 20-30 companies, of which only 10-15 are the most common and well-known brands. But this amount, believe me, is enough, especially for an inexperienced, novice gardener, to get a little rubbed.

What kind of seedling soil should be in order to get high-quality seedlings? Is it necessary to buy ready-made, store-bought, or can you make a high-quality mixture with your own hands? Is it necessary to grow seedlings in the ground or are some other materials suitable for this? Such questions are often asked to the specialists of our consulting center. Let's try to figure them out.

To begin with, let's define the concepts of "seedling soil" and "seedling substrate". They are not the same thing.

Seedling soil (soil mixture, soil) called a mixture of organic components - peat, earth, crushed bark, etc. with an admixture of inorganic components.
Seedling substrate - this is everything that replaces the soil - sawdust, sand, perlite and its varieties, mineral wool, etc.

Requirements for seedling soil

The main requirement is that the seedling soil must meet the needs of the grown crop. There are soils on sale under the name - "Soil for tomato, pepper, eggplant", "Soil for cucumbers", "Soil for flower seedlings", etc. Such a division is not a whim of manufacturers, not a desire to sell one and the same thing under different names to make a profit (although this, alas, also occurs).

For each culture or group of crops, a certain component composition of the soil and the content of nutrients in it are required. There are also numerous "Universal soils for seedlings of vegetables and flowers", but contrary to the inscriptions on the package for growing seedlings, they are often completely unsuitable.

Despite the different composition, all seedling soils must meet certain requirements:

The soil should be loose, moisture and breathable. All components must be selected in such a way that during mixing, further use and storage, the mixture does not cake, clump, harden, and a crust does not form on its surface. There should be no clay in the soil mixture, as its presence negatively affects the physical properties of the mixture, making the mixture unsuitable for growing seedlings.
The soil must be fertile, that is, contain a sufficient amount of organic matter and a complex of mineral nutrients. Purchased soils, unfortunately, often suffer from an unbalanced content of nutrients, and in homemade soils, plus an unbalanced diet, there is often a surplus of organic matter.
The soil should not contain pathogens, fungal spores, weed seeds, eggs and larvae of insects, worms and other living organisms, but it should not be completely sterile. Useful microflora should be present.You cannot grow full-fledged seedlings on contaminated or sterile soil.
The soil should not be toxic, that is, it should not contain salts of heavy metals, radionuclides, oil products, etc. You should not take components for the soil mixture near highways, near airfields, from city lawns, etc.
When mixed, the organic constituents of the soil should not quickly decompose and heat up. With rapid decomposition, the structure of the soil is disturbed and nitrogen is lost, and its self-heating to + 30 ° C and above will lead to the death of seeds and seedlings, as well as damage and death of seedling roots.
Seedling soil should be neither acidic nor alkaline. The optimal acidity (pH) ranges from 6.5-6.7 - this is acidity close to neutral. If you see an acidity of 5.5 on the package with soil, then know that this soil needs to be deoxidized before sowing seeds or picking.
Seedling soil should contain an optimal set of macro- and microelements for each crop or group of crops in a form accessible to plants.

From what it is possible and from what it is undesirable to prepare seedling soil and substrate

The properties of the soil directly depend on which components it is prepared from and on the quality of these components. Quality refers to particle size, degree of decomposition, cleanliness or contamination, etc.

The following are used as organic components for the soil mixture:

high-moor and transitional peat, as well as low-moor peat after freezing and weathering;
thermally treated sod land;
sandy and sandy loam soil from under meadow vegetation, and not from a vegetable garden;
sphagnum moss;
sawdust of coniferous and most deciduous species;
crushed coniferous bark, fallen needles, husks of various grains, crushed peanut shells.

The following organic components are unsuitable for the production of seedling soil mixture:

unprocessed lowland peat;
composts of all types;
leafy ground (rotted leaves);
uncultivated sod land;
rotted manure (humus);
wood shavings of any species;
sawdust of wood, varnished, impregnated with creazote, etc .;
chopped straw, hay dust.

Seedling substrate from sawdust with sand

Inorganic components suitable for use in seedlings and seedlings:

river and bottom sand of fine and coarse fraction, quartz sand;
perlite (volcanic glass), agroperlite and vermiculite;
crushed expanded clay and pumice;
granular styrofoam (packaging foam).

Inorganic components unsuitable for use:

quarry sand, not washed from clay;
not washed sea sand.

There is an opinion that high-quality seedling soil should contain 8-9 components. But is it? Let's see how many components are indicated on the packaging of the soil in the "Composition" column - usually 3-4, no more. So is this bad soil? Not at all! The main thing is what these components are. As a rule, this is peat (high and / or transitional), chernozem or sod land, chicken droppings or compost. Based on the foregoing, it is clear that such a soil for growing seedlings is absolutely not suitable. You need to plant already grown seedlings in it and get a crop on it. It is difficult to grow high-quality seedlings on such soil; you will have to make a lot of additional efforts.

You will get good results by growing seedlings on soil that contains one or two types of peat, sand (or vermiculite) and montmorillonite alumina. But you can do with the soil without alumina. For example, here is a variant of a good seedling soil - sand, high-moor and low-lying peat in a ratio of 2: 1: 1 - a loose, porous mixture is obtained, favorable for root growth. The acidity is adjusted to optimum values using limestone materials (chalk, dolomite flour, marl, ground limestone).

A classic example of a seedling substrate is a mixture of only two components - sawdust and sand. Typically, this mixture contains 65-70% sawdust and 25-40% sand.For decades, its use as a seedling substrate has shown good results when growing seedlings. These components do not have to be purchased, they are easy to find at the sawmill, in the nearest sand quarry. Availability, easy mixing and use with high quality seedlings make this mixture popular. Well, where there are difficulties with wood waste, sawdust is replaced by the husk of cereal grains, for example, rice, sunflower husk.

Seedling substrate options:

40% husk of grains of any grain crops + 60% fine river sand;
40% crushed pine bark + 40% perlite + 20% river sand;
40% coniferous bark + 30% perlite + 10% sand + 20% styrofoam.

It should be noted why the components of the mixture are indicated in percentages and not in kilograms. These are the so-called volume percentages. The components of the mixture should be measured not by weight, but by volume, in liters. Since these components, unlike purchased soil, do not contain nutrients in a form available to plants, it is necessary to use organo-mineral and mineral fertilizers, as well as lime materials to normalize acidity.

What is "good seedling soil"

Under "good seedling soil" everyone understands their own - cheapness, availability in the store, "I buy it all the time", "and my neighbor had wonderful seedlings on it last year," etc. It's hard to argue with this. And yet this is a subjective assessment.

To assess the quality of the soil objectively, you need to take into account all the above parameters. How to do it?

Some, especially meticulous gardeners, bear the ground for analysis in the sanitary and epidemiological station - and they are right. Someone is trying to determine the quality of the soil with improvised means - it is also correct. But the one who immediately sows seeds in purchased soil acts imprudently and takes great risks. Of course, the information on the package does not give a 100% quality guarantee, but you can still choose a reliable soil.

Both purchased and self-prepared soil still requires the determination and normalization of acidity, the use of fertilizers when growing seedlings. It is often necessary to add sand or perlite to the purchased soil to improve its structure.

Pay attention to the content of nutrients - nitrogen, phosphorus, potassium. If it is indicated that these elements are not less than 300-400 milligrams per liter (mg / l) - this soil can be used as a component for seedling soil mixture, for picking or planting adult seedlings in it, but sow seeds into it, i.e. it is not advisable to grow seedlings on it from the very beginning. If the content of nutrients is even higher, such a soil is all the more unsuitable for growing seedlings, on it the seedlings will "fatten" - to increase the green mass to the detriment of the formation of buds, flower brushes.

Garden soil will not be the best soil for seedlings. It is not suitable for many criteria - imbalance in mineral composition, the presence of pathogenic microflora, pests, worms and other living organisms, possible salinity, the presence of heavy metal salts, etc. etc. Young plants (seedlings, seedlings) are very sensitive to all this, and adults are more successful in resisting unfavorable factors.

You can sow seeds for seedlings in the soil for cacti. But before that, evaluate its acidity and adjust it as necessary by introducing, for example, dolomite flour. This is an almost ideal soil mixture in terms of its properties - loose, moisture and air permeable, it has little organic matter and a small amount of nutrients (from 50 to 100 mg / l) - thus, the risk of being affected by various diseases and overfeeding of seedlings is minimal. You just need to be more careful with watering, dressing and perform other equally important growing techniques.

When growing seedlings, the most important thing, in my opinion, is to gain experience from positive and negative results, to identify at what stage mistakes were made, and to prevent them in the future. Indeed, the final result - the harvest - largely depends on how healthy and well-formed the seedlings will be. If the seedlings, that is, young plants, initially fall into unfavorable conditions, they understand that they are not comfortable, feel bad, and under these conditions they cannot develop all the potential inherent in them, being limited to the minimum necessary.

In this case, a rich harvest cannot be expected.

Create optimal conditions for seedlings and get a rich harvest from grateful plants!