Family Cultivation of South African Succulents - Growing Medium
The editor answers questions about succulent knowledge, specifically about the family cultivation of South African succulents and the choice of growing medium. Details are as follows:
V. Choice and Application of Growing Medium
The growing medium refers to the medium for the growth of potted flower roots, mainly to fix the plant and provide nutrients. This medium is not only soil, but also various soilless cultivation media such as organic and inorganic materials, commonly used ones are bark, peat, vermiculite, ceramsite, and so on. There are also unconventional ones like coal cinders, rock wool, polyester foam particles, and decomposed cotton. Water culture and air cultivation are also included.
In general, theoretically, any material that can maintain its physical structure without easily changing during the process of water absorption and root growth, does not produce drastic chemical changes, and can absorb and release water can be used as a cultivation medium.
However, this is just a theory. In most cases, plants can only grow in media that are suitable for them. The so-called "suitable" includes many factors, the most important of which is the pH value, soil salinity (EC), medium composition, organic matter content, decomposition degree, particle size, and so on. In addition, single media cannot provide comprehensive nutrients or may have excessive content of certain components, so they are not suitable for cultivating plants. (Water culture is not discussed here, but in fact, water culture also requires rich nutrients from the outside to allow plants to grow)
Here we need to promote a concept - the root-friendly nature of the medium. In fact, this should be called the selectivity of roots for the medium. Simply put; the stronger the root-friendly nature of the object that plant root hairs like to climb on, the stronger the root-friendly nature. This characteristic is determined by the chemical properties, physical form, and particle size of the planting material. Generally, smaller particles, lower hardness, and looser, more acidic media have stronger root-friendly nature. Root-friendly nature is very important, it indicates that all kinds of properties of this medium are very suitable for plants. The root hairs on the roots can grow and absorb water for a long time. Of course, it is not that there are no root hairs attached to other planting materials with poor root-friendly nature, because the choice of planting materials by plant roots is not foreseen in advance, but corrected afterwards, so root hairs will also attempt to grow on planting materials with poor root-friendly nature, but their lifespan will be short, invisibly increasing the consumption of plants and wasting energy. Over time, the growth gap of plants will be significant. When we turn over pots, we will see that the roots of some plants are very clean, with smooth thick and thin roots. However, the roots of other plants are very dirty, covered with planting materials from top to bottom. If you observe carefully, you will find that the latter's root hairs are more developed, and the upper part is often healthier. The planting materials used by these two pots of plants are often different. This explains the existence of the root-friendly nature of the medium.
Theory will not be introduced in detail, this thing to talk about the opening of tens of thousands of words is not enough, we still talk about the actual.
1. Introduction to various growing media:
(1) Akadama soil
For the cultivation of succulents at home, the best choice is to imitate the soil in their native habitat. The company where Old Ginger works has a project department in the southern part of Africa, so Old Ginger used to ask local colleagues to study the wild soil. Generally speaking, the local soil in Africa is sandy, with the content of sand and gravel about 80%. Some soil surfaces in the shade of trees and grasses are covered with a thin layer of humus. The soil water content is extremely low, and no moisture can be seen even after digging 1 meter in the vast area, but in the area covered by shrubs, slight moisture can be seen below 30 centimeters. From the above situation, the soil composition of the native land is roughly equivalent to coarse sand + decomposed leaves + gravel. It can be said that such soil is not difficult to obtain for most succulent plant enthusiasts, and enthusiasts in Europe and America are indeed using such media to cultivate succulent plants, and the effect is also good. However, for home cultivation, such soil is too heavy, and it is not very suitable for enthusiasts who cultivate a large number of plants on balconies or flower stands. Moreover, it is slightly rough and does not meet the preferences of most students (most students who like succulent plants have a bit of a cleanliness complex, right? Right?)
Therefore, the bourgeoisie represented by the Japanese have developed cultivation soil mainly made of volcanic ash such as Akadama and鹿沼, which not only meets the needs of most enthusiasts in the country, but also contributes several percentage points to the economy of the island country. The soil materials represented by these two are fair and square, and their components theoretically meet the requirements of plants for the medium to the greatest extent. The history of using Akadama soil in Japan can be traced back to 20 years ago. When "Cherry Blossom Mako" was broadcast, there was an episode where Mako's grandfather was sifting Akadama soil, which is probably also an early form of product placement.
In addition to succulent plants, the Japanese also use a large amount of Akadama in the cultivation of other plants. Different products suitable for different purposes have been developed according to different origins. Old Ginger is not helping to advertise Akadama soil. Japan is a horticultural power, but with a small land area and scarce resources, making full use of its own volcanic conditions is also a helpless move. Of course, the poor have their own way of living, so they dig some volcanic ash from the foot of Mount Fuji, pick some rotten leaves from the crooked trees in the backyard, mix them together and use them to plant flowers, and unexpectedly the effect is not bad. Therefore, this scarce resource has been continuously developed, researched, systematized, and marketized, accumulating decades of experience, forming a very sound industrial chain. Large-scale and corporate things will naturally have enough competitiveness, so the Xian soil in Sichuan and the peat in Northeast China are all inferior. To speak frankly, I am not superstitious about Japanese goods, I am superstitious about the system. Generally, things under the system are always more stable than things randomly dug and mined by small workshops.
The biggest advantage of Akadama soil is its low fertility, slightly acidic, breathable, and water-retaining nature. The above four points have almost met the physiological needs of most plants, and for the physiological characteristics of succulent plants, it is almost a perfect match. Generally speaking, beginner players can cultivate succulent plants well without much guidance when using Akadama soil, so Akadama soil can also be called "foolproof soil". Its characteristics greatly reduce the threshold of succulent plant cultivation, and the price is also moderate, so Akadama soil can also be said to be an important factor promoting the rapid development of succulent plants in China.
What needs to be focused on is that not all Akadama soil is suitable for the cultivation of succulent plants. As mentioned earlier, the functions are different due to different origins. For succulent plants, among the Akadama sold in China, the brand "Longquan" is the most suitable. Many students like to use "second-grade line", which actually emphasizes its firmness and non-flocculation. Its texture is high-temperature sintered heavy clay, with poor breathability. Once it becomes powdery, the soil structure in the pot will be greatly damaged. Moreover, due to its hard texture, the root-friendly nature is also poor, it can only be used for cultivating orchids, grass flowers, and pine plants, and is not very suitable for succulent plants. The texture of "Longquan" is sandy soil, although the granulosity is poor and prone to cracking, but its texture determines that even if it is completely broken, it is sandy loam soil. Its basic functions will not be completely lost. Moreover, "Longquan" is not the sintered soil like "second-grade line", so its internal organic matter content is relatively high, and the soil composition is close to that of the soil in the native land. (Don't ask why Old Ginger knows so much. At the beginning, I didn't mind bothering the great masters one by one and asking them what Akadama they used, and I was laughed at countless times, so the great masters who have been asked by me can testify that this conclusion is not fabricated by Old Ginger)
Of course, in addition to Akadama, other materials are not useless either. On the contrary, there are many materials whose functions are not comprehensive, but their characteristics in certain aspects are far superior to the fair and square Akadama soil. For example:
(2) Peat
Peat is formed by the accumulation of the decayed bodies of shrubs and moss plants over thousands of years. Low peat evolved from swamp plants has a high water content, serious decomposition degree, and high humus content, but the EC value is also high, and the pH value is low. Northeast black peat is a representative. High peat evolved from moss and lichen plants in plateau and local plain areas has a low decomposition degree due to long-term drying and frequent exposure to sunlight and rain, so the humus content is low, but the EC value is also low, and the pH value is slightly acidic, with imported FFD peat as a representative. For plants, low decomposition degree, high humus content, low EC value, and slightly acidic pH are the best choices, so the above two types of peat have their own advantages and disadvantages in terms of characteristics. However, in general, high peat is more beneficial for the cultivation of succulent plants.
We are accustomed to using peat as a medium for providing organic matter in the soil, and adding it properly to the whole-grain medium can also play a role in loosening the soil texture and strengthening the soil's buffering capacity for fertilizer and water. In addition, due to its fibrous structure, it can create a microenvironment suitable for the growth of plant root hairs, which has a special effect on the rooting and rejuvenation of seedlings and weak seedlings.
(3) Lava rock
It is generally believed that lava rock should be a product of volcanic ash, that is, pumice stone, foot scrubbing stone and other high-temperature foaming ores, but there are also artificial substitutes such as Tangji lava rock and Nishikawa stone. Since their properties are similar, they are not described separately here. This article collectively calls them lava rock.
Lava rock has a harder texture compared to soil, and its water retention capacity after absorbing water is much weaker, so it can be considered a water-repellent material. The pores inside can store water temporarily, but since they cannot reach the degree of "capillary phenomenon", the water evaporates quickly. However, the pores can reduce the soil density and achieve the effect of loosening the soil. The pH of natural volcanic ash lava rock should be acidic, but artificial substitutes according to Old Ginger's experiments are weakly alkaline, so they should be treated differently when used.
Since lava rock has a low water saturation degree compared to soil, adding lava rock to the soil can reduce the overall water saturation degree of the pot soil, relatively increasing the oxygen content in the soil. This is not the "breathability" we usually think of, as stones do not breathe, the so-called breathability is only an indirect effect.
Lava rock is fertilizer-free, and the EC value has a large difference according to different origins or sources. It is generally believed that the EC value of artificial substitutes is slightly higher, so natural materials should be preferred in practice.
(4) Bark
There are two common types of bark that can be used as horticultural materials. One is pine scale (the lumps on the outside of pine bark), which is relatively expensive and has a low decomposition degree, so it is generally used as horticultural covering material and is not very suitable for cultivation media. The other is the decomposed bark of deciduous trees, which is mostly produced in the natural decomposed accumulation layer of deciduous forests in hilly areas in the central region. The appropriate decomposition degree is 3-5 years. Compared to