Like other plants, columnar cacti such as San Pedro Cactus
and Peruvian Torch
can be reproduced as cuttings. Many columnar cacti have adapted to be able to grow roots from just about anywhere on the plant in the event that a piece would break off. We tend to think of rooted cuttings standing upright, but that is not how it would happen in nature. Most likely, a cactus arm or tip would break off and land on its side. Many people do not realize it, but a broken cactus arm can actually root on its side and send up one or multiple growing tips. But for the purpose of this guide, we will talk about how to root cactus cuttings in the upright position.Rooting cuttings is very simple and actually does not require much effort at all. After all, a cutting that roots in nature has no human help at all. The same idea should be kept in mind when rooting at home. Rooting really does not involve you other than to set up your cactus cutting in the position you want the cactus to grow in. Many people stress themselves out over what they can do or might be doing wrong to get the cactus cutting to root. But the truth is that the cutting will root on its own when it is ready. The amount of time it takes for a cactus cutting to begin rooting can be anywhere from a few months to several months. As long as the cutting does not rot, it will root. So your job in rooting the cactus is simply to set up the cactus, prevent conditions that could lead to rot and have patience.One of the conditions that is helpful for preventing rot on your cactus cutting is providing airflow to the buried tip of your cactus cutting. That means you want to have a soil that is not compact. Perlite is the best way to avoid compaction and provide aeration in your soil. Perlite is a type of highly porous volcanic glass that resembles pumice. Perlite appears as small, round, non-uniform, white particles. Some people mistake perlite in potting soil mixtures for Styrofoam balls. Even if you are using a commercial cactus potting soil, we at World Seed Supply recommend adding at least 50% perlite to your soil. This may seem like a lot, but it will keep the airflow constant so you can avoid rot.Aside from limited airflow, the other condition for rot is moisture. So it is important that your soil is dry before you use it. Unlike rooting plant cuttings where moisture is imperative for the cutting to survive, cactus cuttings
already store the moisture they will need until they root. The cactus flesh does not absorb water well on its own and is prone to infection. It is believed that when the cactus becomes thirsty, it will actually trigger rooting. So aside from rot, it is counterintuitive to the rooting process itself.Once you have your soil mixture you want to fill up a large pot. You want to use a good-sized pot if you have the room. For a 12” cactus cutting
, a pot that is about 10” in diameter and 10” deep is ideal. Sometimes pots can be expensive, so even a bucket or similar large container you might find at the dollar store will work if you drill holes in the bottom. This will give your cactus the room it needs to grow once the roots begin growing. If you want nice thick growth, a good root system is essential.
Before you root any cutting it is essential to make sure that it is well-calloused. Just like a scab over a cut, a wound, in this case a slice, on a cutting will scab over. A well-calloused cutting will be dry rough and hard. If there is any moisture present on the cut, leave it in a dry place to finish healing. If you not follow this advice you will almost certainly have to deal with rot.
We usually position the cactus upright, burying the bottom 3” of the cutting underneath the soil. If your cactus cutting is not a tip, it does not matter which side is up or down. At a 3” depth the cutting should be able to stand up on its own. If not, go a little deeper. This is a suitable depth for helping the cactus stand up. But it also gives enough flesh below the soil for roots to come from. You can even bury the cutting a little deeper if you do not mind it starting out shorter. With a good root system, it may just give you a taller cactus in the long run.
If you are rooting indoors, your cactus cutting can probably get away without being staked. But if you want to be on the safe side or you have pets or are rooting outside, then you can use stakes to hold the cutting upright. You can use two to three stakes place around the cactus to hold it up. Stick them deep into the soil so they can gain a good foothold so that they offer maximum support. Wrap a length of rope or string around your stakes and the cactus cutting at the point where they all meet. You can use several wraps to help secure everything together. Then tie it off. Leave the cutting at room temperature, and the roots will form when the cactus is ready. And most important of all, do not water.