Succulents have very different characteristics compared to other plant species. These plants in fact live in particularly arid and stony places and do not require large quantities of water because they are able to store it for reserve purposes.
However, succulents are now very common even in our homes and this raises the need to identify the most suitable potting soil for their cultivation. In fact, it is not always possible to reproduce the ideal microclimate for the growth of these plants.
The solution for the healthy growth of succulents is represented by the soil or substrate. The soil for succulents must, in fact, recreate the same conditions that the plants have in the soils of origin, that is, in the soils where they develop spontaneously and in the wild. This soil, therefore, must keep the roots of the plant dry enough, but without making it lack the nutrients it needs. In this sense, the ideal soil for succulents is composed of sand, a substance with high draining power.
The sand must be mixed in equal parts with universal soil and then with remains of bricks or shredded stones. Universal potting soil generally contains a good amount of peat, an organic substance that guarantees the availability of nutrients to succulents. As an alternative to universal potting soil, specific potting soil can be used. This product is generally purchased in garden centers, but its costs may be slightly higher than those of universal soil.
Which potting soil to use for succulents and succulents? Here are some tips for an optimal choice
Succulents do not require special care, unlike other plants to be grown in pots, but the main precautions must be taken only as regards the soil to be used.
In fact, excellent soil for succulents must have perfect drainage as its fundamental characteristic: a too compact substrate tends to retain too much water and consequently, the roots of these plants cannot breathe in the right way. Result? A few days and the much-loved seedling will rot, precisely because of the excessive water in the soil.
So what should be the composition of the soil for succulents?
Good soil for perfect growth of these particular plants must have a high percentage of sand (about 50%), which together with the common peat, allows the general substrate to breathe, thus creating a perfect habitat.
In addition, the soil must be particularly dry and chopped: to obtain a good result, it is advisable to use a sieve, with which to sift the soil, so as to use only a very fine compound. An operation that must not be absolutely considered superfluous, but of fundamental importance to create a perfectly draining substrate.
Excellent also the soils that in their composition present minerals: sifted peat, pumice stone (1/3 of the compound), and red lava of grain size between 4/5 cm. A perfect mix that will allow succulents to put on strong roots and to grow, therefore, without any problem.
The one just described is a more difficult soil to find on the market (it is still available from the best retailers), but which can still be obtained by adding elements, perhaps purchased separately.
Only by using materials with these characteristics is it possible to obtain what can be safely defined as the perfect substrate for succulents: optimal drainage, which eliminates any problem of excessive watering. The roots will be much freer.
Obviously, even for succulents, the composition of the specific soil can vary: the percentages of peat, minerals, sand, and so on, directly depends on the thirst of the plant to be cultivated. In fact, the characteristics of the substrate must be combined with the needs of the plant, and the climatic characteristics of the environment where it will be positioned.
potting soil for succulents: how to prepare it
To save on the price of the soil for succulents, you can choose to prepare the substrate yourself, provided that this is possible and feasible. In general, the substrate for succulents is prepared by mixing river sand with medium and coarse grain, with universal soil and shredded bricks.
Before mixing, the sand must be washed and sieved to eliminate any foreign bodies or impurities. The mixture must be prepared with sand still wet, so as to obtain a solid and compact substrate.
In order that the humidity of the sand does not damage the roots, it is advisable to fill the bottom of the pot with expanded clay. This must be added near a grid that protects the water drainage holes. After burying the plant it is also advisable to carry out a light mulching with gravel.
With these measures, you will have obtained a dry, light, well-drained soil without the risk of the succulent plant developing dangerous root rot.
Good drainage is the fundamental characteristic that the substrate of succulents must-have. Compact soil is asphyxiated: it retains too much water and prevents the delicate roots of succulents from breathing. These then, in these conditions, die and rot: in a short time the mold will affect the whole plant from the inside (see Rescue in extremis) and if you do not intervene immediately within a few days, a soft and smelly mass remains.
To improve the drainage of any soil it is essential to eliminate dust. For this reason, it is necessary to have a fine-mesh sieve and sift the soil, which must be dry and shredded, for the operation to be effective.
To begin with, as a base substrate for succulents, you can use half of the common universal potting soil (practically peat) easily found in gardening shops, which you have sieved, and half of river sand.
The substrate I use is almost completely mineral and is composed of one-third of sieved peat, one-third of pumice, and one-third of red lava with a grain size of between 4 and 5 mm (see the photo below). Unfortunately, pumice and lava in bags of this particle size are only found in certain specialized nurseries.
The drainage of this substrate is perfect: you are no longer afraid of having watered too much. During the transplant, it is also very simple to completely free the root system from this coarse compound. Unfortunately, the drawback is that in such an aerated substrate it is also easier for mealybugs to reach the roots of the plants. This can be remedied with a systemic insecticide mixed with water.
The proportion of peat can be increased or completely eliminated based on a plant’s need for water. For some non-Cactaceae succulents, which tend to rot easily in summer, I only use pumice and red lava in equal parts.
In the end, the important thing is that the characteristics of the substrate are combined with the needs of the plant, with the climatic characteristics of the environment in which it lives and with the watering and fertilizing habits of the grower.