The first is filling the pot with soil, sterilize it, moist it and spread the seeds over the substrate, do not bury them. Do not apply an extra layer of mineral. Spray the seeds with water and proceed to cover the pot with a glass sheet, a white paper or a plastic bag (the bag is preferable).
Besides, how do you grow Tephrocactus Geometricus?
To propagate Tephrocactus geometricus, you can do so in two ways. The more common way is to use the method of root cuttings from the mature part of the plant whereby a callous is created and can be placed in new soil. The roots are easily produced from the areoles. Another way to propagate this cactus is to use seeds.