Repotting Young Cacti
Repotting Young Cacti
Written by Sunday, 08 July 2012 22:13
I have previously explained how to grow cacti from seeds; this technique applies to all cacti that are not propagated from cuttings (such as all Astrophytum, Gymoncalicium, Ferocatus etc). It is now time to look at what we are supposed to do once seeds have grown into a miniature copy of the parent plant. Fishkeepers will know what needs to be done; it is similar to what we do with fry once they assume the adult form. Young cacti need space, as young fish do. So they are either allowed to have it or they will “fight” each other for it, applying, to a certain extent, the “survival of the fittest”. Unless the young cacti are repotted they will compete (in growth) between them; the stronger plants will eventually drive the weaker plants to extinction by taking up space and absorbing nutrients. As a result only a very small percentage of plants will remain.
In this article I will look at cacti repotting techniques. Here we go:
This is how two years old Echinocereus pectinatus plants look like: as the seeds were scattered in the seed tray with no particular order this comes as no surprise. Things in the wild are different since the seeds get scattered in a huge, virtually endless, area hence the competition between two plantlets is rather uncommon, at least when it comes to two plantlets of the same species. In the wild plantlets may suffer from the weather if, for example, they happen to fall in an area where there is no sufficient amounts of water or the sun is too harsh etc. In a pot, no matter how big, we need to control the growth rate and the actual density (number of plantlets per pot) if we are to allow all our seedlings to grow properly. In the long run multiple repotting will be required.
The plantlets above are Ferocactus. The seeds came from two different locations hence I propagated them in separate trays. I am sure you have noted that in the upper tray I managed to get only one seedling ... oh well, things do not always go as planned.
When your young plants are due for repotting start by getting ready. Prepare a clean surface ensuring, if required, that you take proper steps to avoid soil, sand or any other kind of substrate, spillage. You will need a number of suitable sized clay or plastic pots (as many as the plantlets you are planning to repot) and enough quantities of the substrate you need to use. The shape of pots is not an issue, you can use one you like or whatever you have available.
Substrate is of paramount importance for repotting. On the main I prefer using what is called the 'average potting medium'. Having said that it is worth bearing in mind that some species need specific elements such as gypsum or sulfur in the substrate in order to flourish. I simply use river sand (with no salt content) roughly rinsed or plain soil or, sometimes, tiny lava grains. My cacti are doing just fine in these substrates. As a general rule remember that all cacti come from dry, nutrient poor soils so they do not really require particular types of nutrients in any considerable quantity.
Start by preparing the bottom of the new pot. Placing small pieces of broken pots (or biggish pebbles) around the bottom allows for proper drainage of the excess water without the substrate being disturbed.
You then need to fill the pot with alternate/mixed layers of sand and soil and this (below) is how the “prepped” container looks like before the introduction of the plantlets:
Time has come to take a good look of a single plantlet: at inspection it looks like a scaled down model of an adult plant. Its root, trunk and thorns are all developed. The thorns are very weak and unable to hurt but this will change with time. A plantlet in detail is shown below:
Carefully remove each plantlet from the seeding tray and place it in the new container. Plantlets should be carefully positioned in a single file and as far as possible from each other. This avoids overcrowding with all its aforementioned dangers. The further away from each other you place the plantlets the longer they can stay in this container, without you needing to repot them again, this time each in their individual pots.
Once all your plantlets have been repotted you are done! Make sure you label the container appropriately, to know what you have repotted in it. In the photo below the two plastic labels in the upper right corner remind me these are all plants of the same kind (genus/species/geographic variety and so on) but coming from two different batch of seeds.
From now on you only need to be very patient and:
- avoid placing the pot in direct sunshine, particularly if the sun is too bright. In the wild such small cacti are shaded by other, not necessarily succulent, plants,
- avoid the pot being exposed in too low temperatures, especially after watering. The plantlets will be fine even slightly below 0° C (freezing point) if in dry soil,
- water the plantlets sparingly, preferrably spraying the pot. If possible opt for small, relatively frequent, showers,
- Fertilize them as if the fertilizer has to be paid in gold (once/twice times a year).
If you are a fishkeeper, instead of using chemical fertilizers that have to be paid for and contribute to the chemical pollution of the environment, you can use the water discarded from your freshwater tanks during waterchanges. It is free and rich in phosphate, nitrates and other useful nutrients for plants. Just remember not to overwater or overfeed them.
Well do you remember the “messy mix” of young cacti I have shown you in the very first image of this article? OK – but you DO need to be patient – ten years after they are supposed to turn in something really close to this blossoming beauty:
Is this beauty not worth the wait? That's all folks, enjoy your cacti!!!
Photos by the author.
Notes:
1. To get your cacti to flower place them in full sun. You can water as required.
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