All the necessary materials and compounds should be prepared before starting to ensure an easy process. It is important to work with clean materials to avoid contamination with fungi or similar, which can lead to a loss of the seedlings.
Materials needed: seeds, pots, labels, substrate, mini-greenhouse, …and a little bit of patience
Here, the whole process is described using pumice as a planting medium, but in fact many other compounds are suitable, as long as they have a loose, porous structure and provide a good amount of moisture after watering, but no waterlogging.
Some mixtures should be sterilised before use as a precaution to prevent infestation with harmful organisms (mainly fungi).
This can be done, for example, by filling the mixture into large preserving jars, moistening them and heating them in the oven. With pumice, this process is usually not necessary.
After having done all the preparations, let’s start:
Fill the cleaned pots with the sowing substrate (~ 2/3 with coarser parts, the upper 1/3 with medium up to 3 mm). Don’t fill the pot until the uppermost level, leave a few mm free, to avoid seeds falling out.
Press the substrate lightly. Prepare labels for the seeds to be planted and put them in one corner of the already prepared pot – putting the labels before planting the seeds avoids seeds to be kicked out by chance when doing it afterwards.
Spread the seeds evenly over the surface. Press them gently to the surface and/or tap the pot 2 times on the ground. Don’t cover cactus-seeds completely with a layer of soil, as they need light to germinate (!).
Put the pots into a mini-greenhouse or some other structure that prevents the pots from easy drying. Water them from the base and after about one hour remove the surplus water, but leave as much, that the very base of the pots is still covered with it.
Close the mini-greenhouse with it’s lid and put it e.g. under artificial lights or in a warm (~22-25°C during day, less in the night) and partially shaded place. Do not expose it to the direct sun, as it will get too hot.
Now it is time for patience and observing the results. Usually seeds of cacti germinate between 2 days to 2 weeks, some can also take longer. Check regularly, if everything’s still clean and growing well, or if there’s some start of fungal attack.
As in many things, some seedlings will grow well, others will take some more time to grow bigger, some even will not grow at all, so never give up after just one try – it is always a process of try and fail, but using the tutorial above, you avoid basic mistakes regularely done.
Happy growing!
Fig. 1 cleaned pots (5×5 cm)
Fig. 2 pumice, left 1-5 mm, right 0.5-3 mm
Fig. 3 filling 2/3 with coarser material (1-5 mm)
Fig. 4 filling the upper 1/3 with material up to no more than 3 mm
Fig. 5 preparing labels
Fig. 6 putting labels in the pot before planting the seeds
Fig. 7 spreading seeds evenly over the surface
Fig. 8 spreaded seeds
Fig. 9 pot in mini-greenhouse
Fig. 10 pots watered in mini-greenhouse
Fig. 11 mini-greenhouse with lid closed
Fig. 12 mini-greenhouses under artificial lights (LED)
Fig. 13 seedlings after a few month
Fig. 14 seedlings in need to be transplanted after ~ 1 year