Guide to the reproduction of succulents
Those who love succulents want to own many. In the long run, the purchase of new specimens will inevitably become very expensive; moreover, we cannot always buy the plants we want in stores and that can be obtained with other systems
Thus we come to propagation, a term which means reproduction or multiplication.
Anyone who simply grows succulent plants without trying to multiply or sow them knows only a part of the characteristics of these exceptional plants; the true grower stands out for his interest in experiencing all those stages that lead a seed to transform into a beautiful graceful plant with beautiful flowers
All plants, and therefore also succulents, reproduce when they have reached a sufficient degree of development. In this way, they ensure the continuity of the species.
Unlike what happens in higher animals, in which reproduction is almost exclusively sexual, in-plant organisms there are three types of reproduction:
gamic or sexual reproduction;
agamic or asexual reproduction;
Gamic reproduction occurs when two different cells, the male gamete, and the female gamete, merge into a single cell from which, by successive divisions, a new individual will be formed
On the other hand, agamic reproduction occurs when new individuals originate from a cell without the fertilization process; it is a widespread phenomenon in lower plants such as algae and fungi
Vegetative reproduction occurs when the new individual originates from groups of cells that detach themselves from the mother plant
Vegetative reproduction of succulents
vegetative reproduction includes all forms of cuttings from stems, leaves, and roots of a mother plant, as well as the offshoot and the division of roots. The result of this form of reproduction is to obtain:
plants that are a miniature of the mother plant;
a large number of reproductions to be exchanged or given away;
for exchanges with other growers, amateurs, or professionals;
an easier and faster reproduction system than sowing
This type of multiplication is also the only means to reproduce those succulents whose growth and development has been altered by some external agent, causing profound changes compared to the original form: this is the case of monstrous or crested variants
Before examining which of these ways is preferable according to the species we intend to reproduce, let’s find an answer to a necessary premise: the amateur has an interest in multiplying the succulents by himself?
Well, a categorical answer cannot be provided and therefore the pros and cons must be seen
Succulent plants, when to proceed to vegetative reproduction
Why NOT choose vegetative reproduction
If it is new, as the amateur does not have the plants that must supply the cuttings or scions for grafting.
Because this type of multiplication requires time and space
Basic knowledge of gardening is required
Why choose vegetative reproduction
If you want to reproduce a variety that cannot be found with nurserymen and whose existence is known
If the amateur is passionate about this multiplication hobby and has space and time necessary to practice it
Vegetative reproduction by cuttings
It is the easiest, most frequent, and affordable tool for everyone to multiply succulents.
It consists in isolating a portion of leaf or branch that is placed in conditions of emitting roots thus forming a plant very similar to the one that produced the cuttings
Many succulents are able to provide us with cuttings (see photo), we are spoiled for choice
First, we have to choose the subject from which we want to reproduce new and similar specimens; to have the cutting, just detach it with your hands, better if you use protective gloves, a lateral branching
Some cuttings, when the manual detachment is prevented by the conspicuous dimensions, are taken by resorting to very sharp knives never using scissors which would produce a very irregular cut with consequent slowing down of the healing process; the use of the cutting of stem which, in my opinion, causes showy and unsightly disfigurements, is not widely used
A separate case is the root rot affecting a plant: when we are sure that the rot has affected the base of the plant we can intervene by removing the entire root system or cutting above the collar; in this way, we are faced with a cutting consisting of the entire plant
The fundamental rule that must be followed is to take those appendages, branches, leaves or rhizomes that do not cause biological damage to the plant which will always remain a beautiful specimen
For all cuttings, exposure is required, for about 24 hours, in a well-ventilated place, to allow the cut to heal; positioning in a humid environment without observing this rule (especially if they are large cuttings) could cause rot with consequent loss of cutting. As for sowing, the same environmental conditions are also required for cuttings: a constantly warm and humid atmosphere to make them root within a few weeks.
This soil to be used as a substrate will consist of a mixture, in equal parts, of sand or gravel, preferably pure sand; it is not necessary to resort to cultivation soil as it is only necessary to root the cuttings
Only when we are fully sure that the cuttings have emitted the first roots, will we be able to transfer them to pots containing cultivation soil. To root cuttings it is not necessary to bury them; I prefer to place them on a layer consisting of grains of pure sand (see photo), so as not to drop them I apply a brace consisting of simple wooden sticks and in general, I use a single vase or container for cutting: until today, this system, it worked out very well
The best time to detach the cutting is late spring or summer; it is not advisable to use the flowering parts of a plant but those that come from the most vigorous shoots, then placing them on a slightly damp substrate, in this way the cutting is stimulated to emit roots. Finally, to remain in the discussion of rooting, two tricks facilitate the rooting of the cuttings:
the use of growth hormones or roots. These are substances called hetero-auxins that have the property of activating the rooting of cuttings
The division of the tufts and the offshoot
Very close to the cutting is the division of the roots or tufts. Many bushy plants form groups of new seedlings that originate from the root system. In this way, we will already have beautiful and formed seedlings and we will only have to take the whole plant, remove it from the pot and do it, avoiding to damage the roots, to separate the various seedlings
Each of these new seedlings will have its own roots which will grow as soon as they are transplanted into a new pot. This type of reproduction is profitable with the shoots of the Agaves and Hawortia
The offshoot – on the other hand – consists of rooting a branch before detaching it to create a new plant. This practice is widespread with those plants whose branches tend to emit roots if close to damp soil
To create a new plant, choose the appropriate branch and approach it to the ground by anchoring it with a U-shaped wire. In a few weeks, the portion of the branch in contact with the ground will have emitted roots. At this point we just have to cut the branch, before the point where the new roots have developed, and to report it.
Certain plant species such as Kalanchoe deserve a separate discussion. On the margins of each leaf, during the vegetative period, they present a large number of already formed seedlings, with adventitious roots. These very small seedlings falling on the ground, in a few days, with favorable humidity and heat conditions, will develop their root system giving rise to a new specimen
Among the other types of cutting that can be obtained from a plant, we could not fail to mention the one that absolutely allows reproducing a large number of fleshy leaf succulents: the leaf-cutting
This very simple and very practiced system consists of taking the leaf of a plant and simply laying it on pure sand
These leaves have large water reserves inside them and, once cut, they will allow the leaf to survive for a long time
The ability to develop a new root system will bring our cuttings to take root within a few weeks; immediately after the rooting phase, the new leaf sketches will begin to appear which, as the days go by, will turn into real leaves.
The generating leaf will guarantee the sustenance of the young leaflets; in fact, over time, we will notice how the cutting will begin to wither until it dries completely. But when this happens, the new seedling will already be formed
The multiplication of succulents in vitro
Since the 1930s, researchers have developed methods for in vitro culture of plant cells. Small fragments of the meristem (plant tissue cells) are implanted under sterile conditions in a solution containing mineral salts and organic compounds in various combinations
Under these conditions, meristematic cells proliferate forming new cells. The next step in vitro reproduction was to find out how by regulating hormonal concentrations in the solution it was possible to produce new mature plants
Using this technique, hundreds and even thousands of sub-cultures of meristematic cells can be produced in a short time and in a small space
Sexual reproduction of succulents
For all those succulents, with fleshy stems, which do not produce lateral shoots or which do not want to be disfigured by cutting the stem, the only means to reproduce them remains the seed
This type of reproduction is called sexual reproduction. The seeds are the result of flower fertilization. It may happen, however, that the plant we intend to reproduce is not yet ready to produce flowers (some species bloom after years) or, more often than not, they are self-sterile specimens; at this point, the only way to get seeds is to buy them