Propagating cacti from seeds is not the most common practice, as the easiest and quickest way to obtain new specimens is by using cuttings. However, seeing a cactus seed germinate is an experience that you should not miss.
We are going to tell you how to do it so that your chances of turning a small seed into a beautiful cactus increase.
Where to get cactus seeds?
Finding seeds for these plants is easy, because you have several alternatives at your disposal:
- Specialty stores in cacti and succulents: They usually have a wide variety of seeds from different species and suppliers.
- Plant markets: Some plant markets offer cactus seeds, especially in spring and summer.
- Online stores: There are many online stores that sell cactus seeds, both national and international.
- Seed Exchange: You can look for cactus enthusiast groups on social networks or forums where seeds are exchanged.
Cactus varieties easy to propagate by seed
Cactus is a very hardy plant once it is established, but as with most plant species, during germination it is especially sensitive to issues such as temperature changes and it can be difficult to get a strong plant.
To increase your chances of success if you're determined to grow cacti from seed, you can try your luck with these varieties, which are a little more resistant:
- Echinopsis: This genus is very popular and easy to grow from seeds, because they germinate quickly and the seedlings grow vigorously.
- Mammillaria: another very common genus and easy to propagate by seed. There are many different species with attractive flowers.
- Gymnocalycium: These cacti are also relatively easy to grow from seed and offer a wide variety of flower shapes and colors.
- Parody: This genus includes globular cacti with conspicuous spines and bright flowers.
- Astrophytum: Although some species can be a little more difficult, in general, Astrophytum can be successfully propagated from seed.
How to choose cactus seeds?
If you want to have a healthy and beautiful cactus that you have seen grow from scratch, pay attention to the factors that must be taken into account when it comes time to choose the seeds.
- Reliable supplier: Buy your seeds from trusted and reputable suppliers. This ensures that they are of good quality and have a high germination rate.
- Fresh seeds: Fresh seeds have a higher chance of germinating. Ask the supplier about the harvest date of the seeds or check if they have an expiration date.
- Appearance of seeds: Look at the seeds. They should look healthy, with no signs of mold or damage.
Not all seeds will germinate, which makes it advisable to buy a few more than you really think you need.
Scarification of cactus seeds
It is a technique used to improve the germination of certain species that have hard or impermeable seed coats. A process through which the seed coat is damaged or weakened to allow water and oxygen to penetrate more easily and thus stimulate germination.
In nature, this can occur through the action of factors such as fire, passage through the digestive tract of animals or abrasion by rocks and sand, but we can also do it in different ways:
- Physical scarification: This method involves gently sanding or scraping the seed coat with sandpaper, a nail file, or a sharp blade. The goal is to weaken the coat without damaging the embryo.
- Chemical scarification: It involves soaking the seeds in an acidic solution or hot water for a certain amount of time. However, this method is riskier and requires experience to avoid damaging the seeds.
Scarification is recommended for those cactus varieties that have very hard or impermeable seed coats, which makes germination difficult. Some of these varieties are:
- Ariocarpus.
- Astrophytum.
- Cactus with large, hard seeds.
In all other cases, scarification is not necessary, as the seeds will germinate easily. If you see that the seed coat is thin, as is the case with Echinopsis, Mammillaria or Gymnocalycium, do not apply any such technique or you could damage the embryo.
When to plant cactus seeds?
The best time to do this is during the warmer months. That is, between late spring and early summer (May-June), because cacti germinate better in warm temperatures and benefit from the increased amount of sunlight available during this time of year.
If you are going to do the sowing indoors, try to help yourself with a grow lamp to stimulate germination.
Step by step to propagate cacti from seeds
Once you have the seeds ready, it's time to get to work:
Substratum
The ideal substrate for cactus seeds should be light, porous and well-drained. You can use a mixture of potting soil and coarse sand or perlite.
First of all, mix these components well and moisten the soil slightly to prepare it to receive the seeds.
Container
You can use small pots, seedling trays or even recycled containers. In any case, making sure that they have drainage holes to prevent waterlogging.
As an extra tip, wash the container thoroughly with soap and water to remove any bacteria or fungus that could damage the seeds.
Siembra
- Fill the container with the prepared substrate, leaving approximately 1 cm of free space at the top.
- Carefully level the surface of the substrate.
- Spread the seeds evenly over the surface of the substrate. Don't bury them too deep, since they need light to germinate.
- You can cover the seeds with a very thin layer of sand or sifted substrate. This helps to maintain moisture and protects the seeds from direct sunlight.
- Gently mist the substrate with water to moisten it. Do not flood it.
Aftercare
Try to keep the container in a place with a stable temperature between 20º and 35º C and that it is very bright. Don't forget to keep the substrate moist and ensure good ventilation to prevent mold from forming.
In a few weeks the seed will give rise to a seedling and, when it is the right size (it will take several months) you can transplant it.
As you can see, propagating cacti from seeds can be a nice experience. Do you dare to try it?