Jungle Cacti are a group of cacti that grow in rainforests. Unlike their desert relatives, these plants do not resemble one another, and many do not have spines. 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.
The most common of these are the Holiday Cacti: Easter Cactus (Hatiora gaertneri), Thanksgiving Cactus (Schlumbergera truncata), and Christmas Cactus (Schlumbergera × buckleyi). These plants are all true cacti despite their lack of prominent spines and inability to withstand the harsh conditions of the desert.
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 on rocks. These plants get their nutrients from the air, dead leaves, and other debris that may have been collected in crotches, cracks, or crevasses. It is important to note that there are no parasitic plants. Those that grow in trees do so for support but do not sap nutrients from their host. We want our soil to mimic these natural conditions for the best results.
Some good ingredients for creating a suitable potting mixture for Jungle Cacti include orchid bark, perlite, potting soil, peat, coir, pumice, and oak leaf mold. The most important aspect of the mixture is good drainage. The perlite helps create this by keeping the soil loose and "airy," as does the orchid bark. Additionally, the orchid bark tends to hold more moisture than perlite or gravel. Pumice can be substituted for perlite. Keep in mind that the orchid bark will eventually break down into the soil. This will create very rich soil that may not be as effective in keeping the roots healthy. Repot your Jungle Cacti every 2 or 3 years with a fresh potting mix. The best time to do this is shortly after your plant has finished blooming. This is when it will be ready to start growing again. You might also add some fertilizer to the new soil.
Well-drained soil is critical for keeping the water from rotting the roots of the plant. With the proper soil, however, watering is quite simple. The easiest way to gauge whether or not it is time to water is to stick your finger in the top 0.5 inches (1.2 cm) of soil. If the soil is dry, go ahead and water. If it is not, wait! Do not let your Jungle Cactus go too long without water. If the stem segments are shriveled and the soil is dry, it probably needs water. Be careful! The stems will also look shriveled if the plant is overwatered, but the soil will be damp. If this is the case, do not give it more water. An overwatered plant will turn yellowish, then get more mushy and dark reddish-brown like a rotten apple. This is because the cells took in so much water they broke and are now dead and rotting. This usually happens from the end first. This will continue even after you stop watering too much, but often you will have enough plants left to start over.
Jungle Cacti can survive in a wide range of light conditions. However, we will assume the goal is not to have plants simply surviving but thriving. The amount and intensity of light are key ingredients for plants to thrive.
There are three lighting situations that are not ideal but often necessary due to space constraints. These are morning shade/full afternoon sun, full shade, and full sun. Let us 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 does not. This is because the temperature is cooler in the morning than in 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. Of course, there are exceptions, as with most things in nature, and some plants 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 long and thin to reach more light.
Not only is light essential for healthy stems, but it also triggers blooming in many species. A particular plant may exhibit fantastic growth with many show-quality stems in ideal conditions but still not bloom. In this situation, exposing the plant to longer and more intense sunlight will trigger it to bloom. Do not forget that plants can get sunburned just like people do. If you have a plant that has been mostly shaded, do not 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.
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