Sowing seeds from your own plants is the most rewarding way of propagating. You see the seeds germinating and young plants grow into mature ‘ornaments’ in your garden.
There are also a few disadvantages: it’s time consuming and labour extensive.
It all starts with the harvesting and cleaning of the seeds.
Bear in mind that some plants hybridise easily. You might think you have seeds of the Aloe ferox because your harvested the seeds from an A. ferox. But whatif this aloe was pollinated by an Aloe vera? We’ve learned our lesson with this. In the beginning we bought quite a few aloes at one of the National Botanical Gardens in South Africa; all nicely labeled with their botanical names. Almost all turned out to be hybrids. Some cacti and caudiciforms (i.e. cyphostemma sp., pachypodium sp.) also hybridise easily. To avoid this for at least 95 percent it’s the best to plant more succulents of the same specie in a group (not nearby species of the same genus) and pollinate manual with a brush. Manual pollination is also a good way of communicating with your ‘babies’.
The best results are achieved with fresh seeds. In general the viability of the seeds declines in time; sometimes even after a month or so. Take the seed-pods from the plant, wash the seed thoroughly (most of seeds are ‘packed’ in an ‘inhibitor’), let the cleaned seed dry and than sow. That sounds easy but it is not always like that. Special precautions have to be taken when harvesting and cleaning the seeds from amongst others euphorbia- and cyphostemma species. The sap of the cyphostemma berries can cause irritation and that of the euphorbias is poisonous. Wear protective hand-gloves when cleaning those seeds. In the description of the different succulent families and individual plants in the future we will indicate this precaution.
There are several recipes for soil mixtures and sometimes they differ per family, genus or even per specie. Each nursery has its own special recipes and all of these seem sufficient. Most books advise you to use a cactus mix which can be purchased at nurseries. Some succulent nurseries apply vermiculite or perlite mixed with a little bit compost. It works nicely and we have tried it a few times on a small scale with good results. But we do not like to apply unnatural products to our soil mixtures. Another disadvantage on the longer term is that if you keep your plants in the original nursery pots with these unnatural products without re-potting them in a proper mix; their lifespan will be shortened.
For most succulents we use for sowing a simple mix of coarse sand (eventually added with some fine grit) with approx. 5 percent fine compost. Mix this thorougly and add some kelpak (SeaGro) dissolved in water (50 cc kelpak in 10 litres water) until the mix is damp (not wet). Fill the seed-tray(s) with this mix, sow and top it of with a layer of sand with the thickness of the seed. In the heat of Summer we top it with a water retaining layer of sand/clay (1:1) mix or clayish loam. This general method works for at least 90 percent of the different succulents with a high (or at least above 70%) success rate. In the description of the different succulent families and individual plants in the future we’ll come back to this subject.
After sowing keep the soil damp. Depending on the temperature mist-spray regularly. Never let the soil dry out. An option is also to cover the seed-tray with transparent plastic foil. If you seed in pots you can use the top of a cola bottle to achieve the same effect.
As soon as the seeds are germinated take this cover away and give the pots/trays a 10 minutes soak from down under as described in the chapter about cuttings
And again: this is all a rough outline. As described before: it’s all in the fingers (not only in your head or in books). Every gardener develops his/her own way of doing things. This rough outline provides you with a nice start for one of the most rewarding things-to-do.