CACTUS & OTHER SUCCULENT SEED SOWING
The sowing of cacti and other
succulent seed is an inexpensive means of propagation accessible to us all. The
growth rate of seedlings is generally slow and one should not expect to immediately have adult plants such as those
which one can obtain through the trade or in plant nurseries. Some species can
flower within two years (e.g. Turbinicarpus, some Mammillarias,
Parodias, Haworthias, Crassulas...), others require longer (e.g. Melocactus,
cerei, Agaves etc), sometimes 5 to 10 years, or even more.
The sowing of Cacti and other succulents is not an exact science,
the results will be different according to the sower, the type of seed,
the light conditions, temperature, substrate and humidity.
Seeds must be of good quality, clean and
preferably fresh, but this last point is not always necessary (e.g. Lithops,
Sclerocactus, Cucurbitaceae may last ten or more years...). Storage,
temperature and degree of humidity also account for much in the conservation
as well as for viability. If
your own seeds generally germinate better than those of others, this
quite normal: they were obtained under the growing conditions of their
your own plants. A sunny or shady position, the temperature, humidity,
substrate, the situation of your glasshouse, facilitated the
“making” of your
seeds, and this medium in which the mother-plants live favours their
“children”. Lastly, there is no waiting for a seed
catalogue : you sow them
immediately, which is generally the best thing to do (however, do not
that some natural germination inhibition may occur and may last for
months) .Storing seeds over several years and under poor conditions
in temperature, high humidity etc.) accounts for a quickly
of germination. Some seeds (Sclerocactus, Tephrocactus, Adansonia,
Dracaena etc.) are very hard and must be sometimes filed or put 10
mn with a depilatory product or in hot water for a week by
changing the water every day. For other seeds, it is best to soak them for 48 hours in a a glass of warm water before sowing.
The temperature for optimal germination is generally
between 22° and 30°C, although
exceptions may exist together with very different factors governing
germination. It is best is to use a heated “mini-greenhouse” equipped with a
fluorescent lamp, a thermostat and a timer for lighting.
The mixture generally recommended is: 50 %
Vermiculite or better quatz sand (as used for the golf bunkers) and 50% peat or Sphagnum,
and providing moisture with a fungicide added to the water (e.g. Benlate or Cryptonol).
However one can obtain good results for Epithelantha and Blossfeldia for
example, using pure pozzolana (crushed lava). After having slightly packed the
mixture, one places duly labelled seeds on the surface of the tray, slightly
packing them with a covering of a mixture of about their own size (a seed of
1cm will be covered with a one cm. mixture, a seed of 1mm. will be covered with
1mm. of mixture. Smaller seeds should not be covered.
Check the sowings by noting the condensed water on the lid of
the mini-greenhouse (propagator). If mould or fungus appear on pots or the
tray, it is necessary to provide additional
fungicide while making sure that the mixture is always wet.
The first germination may appear after 2 days (e.g. Astrophytum,
Turbinicarpus), while most of it starts around the 5th day and continues
until the 15th day. It is considered that a satisfactory germination should be
over 85% on general average, it is to say of all of your pots and of all your
sowings. Sometimes germination starts after 2 or 3 months (e.g. Adansonia,
Dracaena...) and more rarely a year or two from sowing (e.g. Ibervillea,
Sclerocactus...). Moral: if your seeds were not mildewed, keep those pots
where nothing germinated, or re-use the mixture: you will may pleasently be
Once you have decided that all the seed that is going
to germinate has done so, we can then remove the pots and put them at an
ambient glasshouse temperature with just a little shading to avoid sunstroke!
You can transplant the seedlings once they are
sufficiently strong, into a mixture of 1/3 good loam, 1/3 garden soil
and 1/3 gritty river sand.
© Joël Lodé actualized 2015