Growing and propagating cacti is relatively easy to do and can be quite rewarding. For the most part there are three environmental variables to consider to ensure your experience with growing cacti is successful. These are:
We’ll examine these three conditions in greater detail shortly, but first let’s note that there are at least two different groups of cacti. There are the desert cacti which is certainly the first type to come to mind whenever someone hears the word “cactus”. However, there are also jungle cacti which grow in rain forests and other environments that most would consider the least likely habitat for a cactus plant. I’ll address growing conditions for the two separately beginning with the jungle cacti.
Jungle cacti include those species in genera such as Acanthocereus, Disocactus, Epiphyllum, Hatiora, Hylocereus, Lepismium, Rhipsalis, Schlumbergera, Selenicereus, and perhaps a few others. Almost everyone has seen at least one representative from this group even if they were unaware that the plant was actually a cactus. These plants are all true cacti despite their lack of big spines and inability to withstand the harsh conditions of the desert. (Visit the Cacti or Not? page to learn more about what qualifies a plant as a cactus.) Now when we associate “cactus” with one of these, it does not seem unusual that they would require different care when growing than the stereotypical image that comes to mind when we think about the family cactaceae.
Most Jungle cacti are either epiphytic or lithophytic meaning they grow in trees or grow on rocks respectively. This type of plant gets its nutrients from the air or from dead leaves and other debris that may have collected in crotches, cracks, or crevasses. It is important to note that there are no parasitic cacti.
Those that grow in trees do so for support, but do not sap nutrients from their host. For best results we’ll want our soil to mimic these natural conditions.Some good ingredients for creating a suitable potting mixture for Jungle Cacti include: orchid bark, pearlite, potting soil, peat, coir, pumice, and oak leaf mold
It is no accident that I’ve listed water as the second item on the list. This is because a well drained soil is critical for keeping the water from rotting the roots off the plant. With the proper soil, however, watering is really quite simple. I water my Jungle Cacti about once a week. This is a good rule of thumb, but there are exceptions. During extended hot, dry periods I may water twice in one week. Conversely, when it is cool and rainy I might switch to every other week.
Jungle Cacti can survive in a wide range of light conditions. However, we’ll assume the goal is not to have plants simply surviving, but thriving. For the plants to thrive the amount and intensity of light are key ingredients. In my experience the ideal condition for Jungle Cacti is full morning sun and then shade for the afternoon. All the plants I have in this ideal condition exhibit robust and healthy growth.
There are three other lighting situations that are not as ideal, but often times necessary due to space constraints. These are morning shade/full afternoon sun, full shade, and full sun.
Let’s explore these conditions further. It may seem that shade in the morning and full-sun in the afternoon should produce the same results as full morning sun/afternoon shade, but it doesn’t. This is because the temperature is cooler in the morning than the afternoon and for many plants the afternoon sun is a little too intense and plants will often take on a sickly-yellow appearance and may develop spots. In full-sun these symptoms will be even more apparent.
As with most things in nature there are exceptions and some plants actually prefer full-sun and thrive in it. In full shade the plants will don a dark-green healthy appearance, but the stems will be stretched out long and thin in an attempt to reach more light.
Not only is light essential for healthy stems, it also triggers blooming in many species. In ideal conditions a particular plant may exhibit fantastic growth with many show-quality stems, but they won’t bloom. In this situation exposing the plant to longer and more intense sunlight will trigger it to bloom.
Don’t forget that plants can get sunburn just like people do. If you have a plant that has been mostly shaded, don’t just stick it out in direct sunlight or you will certainly end up with a badly scared cactus. This is even true for desert cacti that occur naturally in extremely hot, intense sunlight.
Desert cacti hail from throughout the arid regions of the America’s and surrounding islands. There are no desert cacti native to the old world and only one jungle species that occurs in Madagascar. Despite this, many people envision cacti growing in pure Sahara Desert sands with practically no water.
This common mis-perception should not be in your mind when you are preparing an environment for your desert cacti. We’ll explore the requirements for growing healthy desert cacti shortly. First let’s summarize the different types of desert cacti you may encounter. There are small rounded, flat, or cylindrical plants; there are shrubby, segmented, and sprawling kind; and there are the large columnar and tree-like giants. Although even within each of these groups growing conditions vary from one plant to another.
Most cacti prefer a nutrient rich, rocky soil with good drainage. To create a suitable growing median for our desert cacti we’ll use some of the same ingredients that we used for jungle cacti as well as some new ones. These are pearlite, pumice, potting soil, rocks, sand, peat, coir, and gravel. After trial and error and advice from other growers, I have settled on an easy, well-draining mix. This mix consists of 60% pumice, 20% coir, 20% Supersoil (topsoil). The pumice can be replaced with pearlite or vermiculite and the coir replaced with peat.
Their ability to survive in extremely hot, arid, harsh habitat is a truly fantastic attribute of cacti. However the notion that cacti do not need water or that they actually must avoid water in order to survive is unquestionably false. The reality is water is essential for all cacti to live. Their reputation comes from their ability to survive in areas where water is available in small amounts or is delivered infrequently. Most desert cacti can sustain long periods of drought. This is because the last time water was available to them, they stored as much as possible in their tissues.
Desert cacti are made to thrive in their native environment, which is most likely not anything like the environment where you’ll be growing them. Even so, when it comes to watering cacti, there is no reason to artificially create drought. Whether potted or in the ground, a good time to water desert cacti is whenever the soil is dry. In hot, dry areas watering once a week is acceptable.
Source: Growing cacti.com