PROPAGATION FROM SEED
COLLECTION OF SEEDS
The fruits of plants in nature are divided into dehiscent and indehiscent. The dehiscent fruits are those that, when mature, open spontaneously to release the seeds; indehiscent fruits on the contrary not open spontaneously and the seeds remain inside them until germination or rotting. The images are examples of both types of fruits which, although not belonging to the family of succulents , help us to understand how the nature works.
The fruit of Pittosporum tobira opens and releases the seeds naturally.
CLEANING OF SEEDS
Regardless of the type of the result of the seeds origin, clean them and disinfect them so that they do not develop mold or rot. There are several systems and techniques, depending on the habits of each; the most convenient is to put the seeds in a sieve with a mesh smaller than the diameter of the seeds themselves and submit it to a gentle stream of tap water, rubbing the seeds with your fingers.
DISINFECTION OF SEEDS
It's better to avoid storing the seeds directly collected in this way: despite washing, maybe even accurate, traces of pulp or other organic material could continue to adhere to the surface of the seed and vehicular mold and rot. It is therefore advisable to carry out the cleanup: the three techniques presented here differ slightly one from another, but they are all equally valid.
a) sterilize some water bringing it to boil for about 2 minutes, then leave it cooling until it reaches the temperature of 60°C. At this point, the seeds are immersed in the water and left to soak for about 30 minutes.
b) prepare a solution of sodium hypochlorite and water in a ratio of 1:15 (one part of sodium hypochloryte with fifteen parts of water), the seeds are immersed in the solution and left to soak for about 30 minutes.
c) get a fungicide powder (fairly easy available on the market) and put it over the seeds surface.
CONSERVATION OF SEEDS
At this point, the seeds of our plants are ready to be stored pending the sowing. With some exceptions, the seed germination rate decreases as the age of the seed increases: the vast majority of seeds in the first year of life has a high germination rate, which then begins gradually to decline. Adequate storage allows to preserve seeds viability. Despite being in a period of dormancy, the seeds are alive: their sweating must be guaranteed, taking care to keep them in a cool place. It's preferable to store them in paper sachets open from one side rather than in containers or plastic bags hermetically sealed; particularly indicated are the sachets of waxed paper semitransparent, that compared to plastic ones have the advantage of not to be chargeable with static electricity, and then of allow an easy extraction of the seeds, which would otherwise tend to remain attached to the plastic. Finally, note that the low temperatures lengthen the period of germination, so it 's always best to keep the seeds with a few degrees less than in most.