The reproduction of the cactus , sexual reproduction or by seeds, is the most natural form of propagation, being also inexpensive, simple and accessible to all cactus enthusiasts.
The technique of sexual reproduction or by seed , is slower, but very grateful as we will see our new plants grow in quantity and in a small space.
The vegetative or asexual reproduction is that achieved by means of cuttings or shoots.
An important consideration we must make is that when we multiply our plants by seed, we will have plants that will NOT be identical to their parents.
If we want identical plants, we will have to reproduce them using the cutting technique. This way we will have our plant, cloned.
Cactaceae, commonly known as biznagas, are succulent plants.
Its origin is distributed throughout the American continent, from southern Canada, to Patagonia, although it is in Mexico where the greatest concentration of species are found.
For this reason, its habitat is generally arid and semi-arid, although it can also be found in temperate, tropical or subtropical climates.
It is important to comment, that you can get a variety of hybrid plants. That is, we can cross two different species, with which we will obtain a new plant or a hybrid.
With hybrids, we will generally achieve greater and more spectacular flowering, coloration and flower size. For the hybridization of our cactus, we must pollinate manually, instead of being pollinated by insects or wind.
We will use a fine brush, with the brush we will remove the pollen from the stamens and we will paint with it the pistils of the plant.
We will clean the brush well at the end, so as not to intermix the pollens and we will not pollinate our flowers correctly.
The cactus and succulents can be planted at any time of the year. The ambient temperature for germination is usually between 20ºC and 30ºC. More or less temperature, may not achieve the germination of the seeds.
According to the species of cactaceae that we have, it will give us a fruit that can be fleshy, semi-dry or dry .
It can present the “dehiscence”, this is the fall by themselves of the seeds, when the fruit ripens.
If the fruits are fleshy, it is advisable to remove the seeds as soon as possible, since the mucilage or internal pulp, dries and hardens making it difficult to extract them.
To do this, open the fruit and crumble it and drop the seeds.
Put them in water, remove those that float and not sow them.
If the fruits are semi-dry, make cuts along the fruit and remove on a paper, leaving to dry well.
If the fruits are dry, extract the seeds with fine tweezers or suck them.
How to get the seeds
The seeds can be obtained from the fruits, through direct harvesting or by purchasing certified seeds in nurseries.
Since most cacti are hermaphrodites, we will have male and female reproductive structures.
To do this, achieve fertile seeds of ripe fruits and as we have said, pollination should be done , between the pollen of the stamens (male organ), deposited on the pistils (female organ) of the flower.
When the fruits are fully ripe, the seeds will be detached without difficulty, by crushing the fruits on a clean cloth or napkin. We will let dry a few more days and get only clean seeds, of any adhering pulp that they could have.
The seeds should be of good quality, be clean and preferably fresh, although there are species in which this is not necessary.
Avoid the condensation of water on the seeds, as it could cause the presence of fungi. In case of their appearance due to excess moisture, spray a fungicide on the substrate.
For efficient germination, the adequate temperature will be between 20º and 30ºC, generally. The best thing is to have a temperate zone or seedbed in those conditions.
For a nursery of cactus , the good thing would be to have a substrate that had 50% of the mixture of peat, something humid and another 50% of vermiculite.
Another good substrate will be 50% of fine mulch, 40% of river sand washed and 10% of blond peat or black peat, all well mixed and without thick parts.
We can also prepare 60% black peat, 20% coarse sand and 20% charcoal powder.
Other mixtures for cactus seedlings will also be adequate.
There is a method that we have not commented yet and that in this section does not fit at all, since it is sown, but not on substrate as such, but on dampened cotton.
It is a method well known and learned since childhood. This method gives us a greater speed of germination, but the roots can be damaged, being very fragile entangled in the cotton.
Beware of handling germinated seeds.
Sterilize the substrate.
You could even sterilize the mixture, putting it in the microwave for 12 minutes, depending on power and quantity or in the kitchen oven, about 2 hours at 200ºC.
It is also possible to sterilize them in a bain-marie, it will take about 40 minutes of cooking.
If it is a question of sterilizing large quantities of substrate, up to about 60 kilos, we will use formaldehyde in 15% solution, these is about 150 ml of formaldehyde, per liter of water.
Place the substrate in a plastic bag with the formaldehyde solution . Closes it well and after 12 hours, it is spread and left to air dry for 3 days, in a well-ventilated place.
This way we eliminate the possible presence of fungi.
In any case, use the necessary safety systems, glasses, gloves, etc., given the toxicity of formaldehyde gases.
Planters or containers for planting.
According to our ability or ambition when making cactus seedbeds, as to flowerpots , we can do something from small and personalized, to something big and more professional.
The basic materials can be, from plastic cups to seedlings of several meters in length.
It is recommended that the containers we use do not have a substrate layer greater than 4 to 6 cm thick.
Glasses, tubs or plastic or glass jars, small containers and where the possible presence of fungi is easily controlled .
In plastic or clay pots, at least 7 to 10 cm in diameter or rectangular hermetic .
We can go to the market and buy, in establishments to that effect, electric seedbeds, which come to be like mini greenhouses.
They have a transparent plastic cover and electrical resistance that allow to adjust the interior temperature, in colder times.
We can also use seed starter or seed trays
The containers used must be sterilized or disinfected before sowing. We will wash them with a 10% chlorine solution, that is, 10 ml of chlorine in 90 ml of water.
After washing them with chlorine, rinse well with boiled water.
The process of planting.
To plant correctly, we will make sure that both the substrate and the seed are deposited on the seed. That is, if the seed is about 3 millimeters, will be placed on top of this, about 3 millimeters of substrate.
In the case of very small seeds, less than 1 millimeter, just by letting them fall on the substrate, it will be enough.
Steps to follow in a general way.
To achieve success in planting and germinating our seeds, we will do;
1.- Fill the container with the prepared substrate , leaving about 10 mm free. Previously we will have put the seeds to soak in water, for a day. This will accelerate germination.
2.- Try to keep the container with good drainage, placing in the bottom thick sand with small stones or gravel.
3.- Water the substrate by immersion of the container or pot in water, and the water will rise by capillary action. Let the excess drain.
4.- Sowing, distributing the seeds throughout the substrate, without clustering one on top of the other.
5.- If the seeds are more than 1 mm thick, cover with the same substrate thickness. Distribute well and press lightly so that the seeds are more subject to the substrate.
6.- We will cover with a film of transparent plastic film, so that we will maintain the humidity and stable temperature. In a week or so, we will observe the first outbreaks.
7.- When it is necessary to water, do it by spraying or spraying gently and making sure that the seeds do not move, allowing them to settle well.
8.- You can also water by immersion in a container with water, from which it will absorb the necessary water through the drainage holes. Remove the seedbed from the water, when moisture is observed above the substrate.
9.- After about 30 days, you can open holes or remove the plastic film and allow the passage of air, so that moisture is reduced and avoid the appearance of fungi.
10.- For the control of fungal pests , treat it with an effective commercial fungicide, applying it with care.
11.- Keep the humidity, without puddles with a good drainage, making frequent waterings.
12.- Make sure that your substrate maintains the level necessary for the buds, adding fertilizers every two weeks, but always dilutes the concentration of the fertilizer in half.
13.- Seedbeds should be avoided in the sun / direct light, to avoid the dryness of the substrate. Yes, there must be good indirect lighting.
14.- After 30 to 60 days, or when the shoots reach about 10 to 15 mm in height, we could remove them from the seedbed and transplant them, although we can better leave them until they reach 20 mm.
15.- For the transplant, it will depend on the species and its growth, whether we do it sooner or later. We will remove them from the substrate, with a spoon or similar without damaging the fragile roots.