The rhizome is considered the most vulnerable place for cacti. But only if we are talking about cultivated plants, in the natural environment, the root system is an example of how this part of the succulent can be useful, functional and communicative.
Not all cactuses have similar roots in size, appearance and structure, everything depends on the type of a particular specimen and conditions of growth. Moreover, even the representatives of the same species may have different roots, if they are taken from different climatic zones. What are the roots of cacti and how do they differ from the root systems of other vegetation?
Abilities of the root system of cacti
The roots of these succulents can transform under the influence of the environment and change their habits, if the plant is in danger
If the cactus grows in the nutrient soil with sufficient moisture, its roots are short and thin. After all, there is no particular need to build up a strong root system, which takes away a lot of nutrients and energy from the slow growing specimen.
Lack of moisture and / or mineral salts, makes the roots of the plant to show effort – they begin to extract from the soil crumbs of salts and stretched to get to water sources. Surprisingly, the length of individual roots can be several times the height of the aboveground part of the succulent.
The root system of cactus roots seldom goes deep into the ground, only if there is an urgent need. But it can proliferate abundantly in the upper layers of the ground, covering a huge area around, absorbing the slightest crumbs of moisture, whether they are drops of scarce rain or abundant dew, slightly irrigating the soil.
Large specimens of cactus have anchor roots, growing vertically. Their main function is to keep the plant on the surface, not letting it fall to the side under gusts of wind or its own weight. But sometimes they also start to grow upwards after reaching a decent depth, performing another task – to extract water for the plant.
So, if a cactus has developed a powerful, abundantly branched root, it means it lacks nutrients, and thus, the plant manages to grow fully.
Cactus plants differ significantly from other plants, and it’s not just their unusual appearance. Since they live in harsh conditions, nature has provided them with various devices and the root system is no exception:
As soon as the conditions become favorable and the plant begins to receive regular water and salt, it, unlike other representatives of the flora, does not switch to a fast growth mode, and gets rid of excess roots. It is not so easy for Succulent to “maintain” a sprawling root system, providing it with food, so some of the roots die off when they are no longer needed.
During prolonged droughts, when moisture reserves are depleted but not replenished, the succulent gets rid of its peripheral roots. There are only important parts left that keep the cactus in an upright position and pick up the water particles. As a rule, they are close to the stems.
On the surviving roots, cones of waiting roots are formed, which can grow when there is no moisture deficit. In a short period of time they turn into a branched web and saturate the hungry plant with food and water.
How do the roots absorb water and mineral salts?
Biologists have studied the complex process of absorption of moisture and salts by the roots. Water penetrates the cell through the action of osmotic pressure. And in cactuses, it is much smaller than in other drought-resistant plants – sclerophytes.
This indicator does not allow cacti to grow abundantly in areas with saline soil, and, in addition, warns floriculturists – to feed their exotic pets with mineral fertilizers should be moderated, because when salt accumulation in the ground plant dies.
This phenomenon is quite understandable explanation:
If the concentration of salts in a cell exceeds the amount in groundwater, the osmotic pressure of the plant is higher and allows them to suck moisture from the soil.
And if the soil contains more salts, they create an increased osmotic pressure, through which they take away from the root system fluid contained in the cells.
Naturally, in the second case, the succulent expects death.
When the osmotic gradient is normal, the moisture enters the cells without any difficulty and at a certain stage, the concentration of salts in the cells, and thus the osmotic pressure, should decrease.
But, at this point, the transport system of the membranes is connected, whose ion pumps can selectively capture and move the dissolved salts inside the cells. The cells use the solar energy stored by the succulent stem during photosynthesis.
The mineral components that have penetrated the cell get into the stem and are included in the metabolic processes. In this case, the level of osmotic pressure is kept within normal limits, maintaining a full metabolism.
The root system, which goes into growth, sends the stem the appropriate hormones, which signal that it is time for active growth. Therefore, all processes in the above-ground part of the cactus are activated and it comes to life.
All parts of the plant are quite mobile and are able to replace each other, so, during dry periods, the stem supplies the root with moisture, but in wet weather the opposite.
Exception to the rules
Cactus plants are a numerous family, including a variety of succulent plants, and not all of them have a standard appearance. For example, some varieties have a tendency to store the bulk of moisture not in the stems, but in the root! The most abundant cactuses of this group are non-treatments, which come from South America. The diameter of their stems does not exceed a few centimeters, while the root can weigh more than one centner. 90% of this root system is water, which it shares with the stem during droughts.
Some cactuses with turnip roots have another unique ability – in prolonged dry periods, they can “go” into the ground, hiding from the scorching sun and heat. This “trick” is possible thanks to the ability of the massive root to significantly reduce in size and pull the stem into the ground. Thus escapes from the drought of loophore.
Conditions of maintenance of room cactuses
The roots of the plant have many tasks and, above all, they must supply it with organic substances and minerals necessary for the development of the aboveground part. And how they will cope with their functions depends not only on the size and appearance of the succulent, but also on the timely readiness for budding and fruiting.
The root system of plants, including cacti, is “working” not by itself, but with an obligatory orientation on external factors:
Duration of the light day;
Air temperature and humidity;
Soil quality and humidity.
Lack of lighting – leads to deformation of the stem, reducing the size of the thorns.
Excess light – in this case, the growth of the succulent may slow down and it experiences a depressed state.
Elevated air temperature (more than +30 degrees) – also can lead to a depressed state, and if the sun is too bright, it causes stem burns and even the death of the whole specimen.
Excess moisture in the soil – a dangerous state in which the root system rots and/or the growth dynamics of the stem of the cactus is disturbed.
Prolonged drought – provokes the destruction of the root system, as a result of which the stem stops receiving food.
As a rule, cactus growers only in the process comprehend all the subtleties and nuances of growing these exotic succulents. However, it is important to consider the main points as soon as the first cactus is in the house.
First of all, fertile, dense soil, containing a lot of organics, cactuses are not suitable. It is important to consider that in nature, they grow in poor, stony soils, which have very few organic components, but they are saturated with minerals. Therefore, for green pets should use a porous, loose soil mixture.
Adult cactuses are watered only when the earth lump dries. In winter, if the plant is kept in cool, moisture is not made or scarcely watered every 4-5 weeks.
Liquid mineral formulations are suitable for this purpose, which are better diluted in more water, reducing their concentration. Cactuses are fertilized only during the active vegetation period – from spring to the end of summer, autumn and winter plants do not need any additional fertilizers.
Breeding from winter hibernation
It is important to properly “wake up” the roots of the plant after a dry and cool overwintering. At first, it is recommended to spray the stems using a fine spraying sprayer. Stems will “share” moisture with roots, which will prevent their rotting.
Experienced cactus growers recommend during transplants to inspect the rhizomes of their wards, removing dead, rotten or damaged parts. This will help to avoid serious problems in the future.
The roots of a cactus are a system thought out by nature itself, dealing with functions that may seem impossible to perform. They are transformed, modified, equipped with additional devices if external factors require it and make these succulents resistant and very viable. Therefore, the owner of cactuses should take care not only about the above-ground part of the plant, but also about its roots, without which the green pet will not survive.