Consequent to several of our customers inquiring as to the best way to propagate Trichocereus cactus species, we thought we’d write a little about an arguably less popular method (at least compared to tip cuts and growing from seed) – the use of stem cuts as mother plants. This alternative cultivation method can also be used with many other cactus species, so it’s always worth experimenting if you’re not sure (and have enough material to work with for comparison). Other techniques which we’ll probably cover on this site one day soon include the “log method”.
Basically, whenever you take a tip cutting from a cactus, you have the option to also make one or more stem (mid-section) cuttings, besides the rooted base and growing tip. Obviously, this is very much dependent on the overall size of your plant, but most collectors would agree that a mid-section anywhere upward of roughly ten centimetres high should suffice to start a new mother plant (the general thinking is the bigger the cutting, the more energy it has to put into forming new roots and pups).
Once it’s had sufficient time to form a strong and healthy root system, the new mother plant should soon start to grow one or more pups from around the edges of its calloused-over top and/ or bottom surface. These pups can either be sliced off once they are of a suitable size (try to wait until they’re at least ten centimetres tall before removing), else left to continue growing into new arms of the main plant.
The beauty of this cultivation method is that it makes it possible to quickly turn one, relatively small, cactus into several to many mother plants, each putting out one or more new plants per year. Of course, this is all provided that you can handle the less than competition standard appearance of the resultant plants!
Anyway, read on for our guide to making cactus stem cuttings…
How to Make a Cactus Stem Cut
How to Make a Cactus Stem Cut – Materials:
- Commercial cactus soil
- Growing container (or the ground)
- Sharp-bladed knife
- Trichocereus cactus (or other suitable species)
- Alcohol wipes (optional)
- Cactus/ thorn-proof gloves (optional)
- Soap (optional)
- Tape measure (optional)
How to Make a Cactus Stem Cut – Method:
- Optional: Wash your hands with soap and water.
- Optional: Wipe the knife with a couple of alcohol wipes. This is especially sensible if making multiple cuttings in one session (in which case also wipe in-between each cut), as it reduces the risk of mould and other bacteria messing things up.
- Optional: Gently but firmly, use the knife scrape off any visible scale or other insects (particularly common on plants grown outdoors or from cuttings from plants grown outdoors).
- Take the donor plant from which you wish to excise the stem cut. We like to wear our lovely cactus gloves to do this, unless we’re cutting a shorter-spined type. First, decide how long you wish the tip cutting to be, making sure to leave enough room for a ten centimetre or more stem cutting, and at least a ten centimetre rooted stump too (which will continue to put out new pups over time).
- Carefully and swiftly use the knife to cleanly slice through the cactus. One smooth, firm, slightly-angled (to reduce the risk of pooling water and hence mould/rot) cut is best, preferably a few centimetres from any areoles, etc.
- Take the newly divided plant (tip, stem section(s) and rooted base) and place somewhere dry and warm, although avoiding strong, direct sunlight.
- Dependent on the local environment, the cut surfaces should callous over within anywhere from a few days to a month or so. At this point, you’re ready to move on to the next steps.
- Fill the growing container with a roughly equal mix of soil, perlite and sand (or a similar, well-draining mix). You can pasteurise this first if you’re on the more cautious side, but we generally avoid this ourselves. Alternatively, you can also try rooting in a completely nutrient-free substance, such as pure perlite, although will need to monitor the plant closely until it’s time to move to a more nutritious medium if so.
- Take the stem cutting (right side up or it won’t root!) and place it in the centre of the container, gently pushing it a centimetre or two into the surface of the medium.
- Now it’s time to leave the cutting to form roots, which can start to visibly form as soon as a few weeks subsequent to planting (or even before, if you leave the cutting laying around for a while before planting). It’s important not to water the plant at this stage, as you want to avoid encouraging rot and other nasties.
- It’s possible to encourage pupping by means of pruning or other mechanical damage, or via the application of a suitable fertiliser, GA3 hormone or similar.
- Wait until the calloused ends are completely dry to the touch (they should be quite hard) before planting them for best results. Anything that grows on the cut edges but can be wiped off is usually fine; if the end starts to turn soft, rot, etc., simply cut it off a little further up until there’s no trace of it left on the remaining cutting, then repeat the drying process.
- In our experience, this technique is especially well-suited to regenerating desirable strains which are getting older and/or are damaged, infested, etc.
- Some people prefer to slice their donor plant into as many slices as possible (no less than ten centimetres thick is preferable), others swear that larger cuts will put out more or more vigorous pups once rooted. It’s often been hotly debated by aficionados, but, personally, we’re uncertain if there’s any practical difference.