The coral cactus is a fascinating plant with a captivating and unusual appearance. The most striking feature is its crest resembling a rugged sea coral. So, do how do you grow and care for a coral cactus?
These are the basic guidelines to take care of the coral cactus:
- Use a strict ‘soak and dry’ method when watering.
- The coral cactus needs a good provision of light. If outdoors, make sure it doesn’t get burnt by the sun.
- Keep it away from humidity. Make sure it has good airflow.
- Protect your cactus from the frost during winter.
We’ll examine the basic and advanced care guidelines for the coral cactus in this article. Read on for more.
Coral cactus basic care guidelines
The coral cactus originated in Africa and then developed in Thailand. It’s called a ‘franken-plant’ by some, since it’s actually two succulents in one. Let’s go one by one through the main caring tasks you should consider when growing a coral cactus.
The placement of the coral cactus depends on several factors. As you read this article, you’ll learn the nitty-gritty of where a coral cactus will actually thrive. Having said that, there are some basic pointers to follow.
If the cactus is indoors, make sure it doesn’t suffer from humidity and receives a good amount of daily sunlight. If it’s outdoors, the coral cactus should do well, though be careful that it doesn’t get damaged by excessive sunlight. Partial shade will do quite nicely in this case.
When it comes to temperature, it’s important to note that this cactus doesn’t like the cold. This surely conditions the placing of the coral cactus. It also stresses the need to bring in the cactus if it’s outside and frosty conditions occur.
Light & Temperature
The coral cactus enjoys average indoor temperatures. It can actually grow outdoors quite successfully and can grow throughout the whole year.
It’s important to note that the coral cactus thrives in USDA zones 10 and 11. In that sense, the coral cactus is right up there with the hardiest of cacti. If we house the coral cactus in colder places though, we may want to keep the plant indoors and only take it outside in the summer.
Note that if the plant is indoors, it should be getting at least 3 hours of good sunlight each day.
The fact that the coral cactus thrives in warmer weather should give us an indication of its light needs. The coral cactus needs a lot of plenty of light to thrive. Indirect or partial light will do a lot of good to this plant.
The best temperature for coral cactus growth is usually between 60º to 85º F (15º to 30º C). Having said that, although the coral cactus does like a lot of light, some owners place it in areas where it may enjoy some partial shade.
This way, sunburning of the surface is avoided. Therefore, it’s best to keep the coral cactus away from temperatures below 60 F (15 C).
When it comes to watering, as with other cacti and succulents, we want to use the ‘soak and dry’ method. As we know, such a method dictates that we should wait for the soil to be completely dry before watering.
When watering, we want to drench the pot, pouring at the base of the plant.
Once the pot is drenched in water, and leaking through the drainage hole, we must let the plant be and wait for the soil to dry off before we attempt another watering session.
The ‘soak and dry’ method basically replicates the natural environment that cacti, and many other succulents encounter naturally. A desert environment will usually have a lot of sun for days and weeks on end. Suddenly, it may start raining. In the desert, when it rains it pours. The coral cactus will benefit from this approach as well.
It’s important to remember that we really want the whole soil to dry off. The top layer won’t do in this case; we want a top-to-bottom dryness. To make sure that this happens, some owners use moisture meters or wooden chopsticks which they’ll insert into the soil to check for moisture.
If we err, it’s best to do so on the side of caution and underwater a bit. Overwatering is a sure killer of the coral cactus.
Soil is a vital consideration when talking about the coral cactus. Most owners tend to use a simple 50-50 combination of potting mix and sand. Others will use a more commercial well-draining mix. Drainage is a major consideration and that’s the reason for a mix such as this one.
There are ways to make our own soil mix with these characteristics. As we know, root rot is a killer of succulents, including cacti. It’s no different with the coral cactus. There are certain things which make for a good soil mix:
This is really the most important consideration. It implies that a good soil mix will usually contain lose and grainy soil as the main basic substrate to be used. Most owners creating a soil mix with perlite, pumice and coarse sand to achieve that drainage.
Roots will need space to breathe. This is why some coral cactus owners will repot the plant as soon as they buy it. They intend to make sure that the soil that the vendors put the plant in is not too compact and inhospitable to the roots.
No excessive nutrients:
Some owners may be too eager to provide the soil with a lot of nutrients and fertilizers. In this, there is some need to be prudent. We’ll talk about fertilizing below.
When creating our soil mix, some of the following materials may come in handy:
- Gloves: in the case of the coral cactus they are always vital, since this plant is toxic.
- Measuring cups and buckets.
- Small shovel: usually called trowel.
The coral cactus enjoys good airflow. This helps combat humidity, which is great. As with so many other things though, prevention is the best policy. Placing our coral cactus in a dry environment is always the best approach. This way, we don’t need to worry about humidity and air movement.
Does the coral cactus like humidity or not? This is a good question and not without controversy amongst experts.
Some owners think that the coral cactus actually likes humidity as long as there is good airflow. Others think that the coral cactus should be treated much like we treat cacti. That is, that it shouldn’t be exposed to humidity and that it thrives in dry and sunlit environments.
The latter solution is the most likely. It follows the principles that we are used to about cacti (dry and well-lit placement) and is really the safest route to follow. Remember, succulents such as the coral cactus can withstand drought conditions but will seldom recover from overwatering, excessive moistness or too much humidity. Better to err on the safe side.
Coral cactus advanced care guidelines
Propagating the coral cactus is possible. Cuttings are made during spring, dried out for about two weeks before being placed in a pot.
It’s important to stress that the coral cactus is a ‘franken-plant’. It’s made of two different plants and this obviously makes propagation a bit different.
We’ll need to propagate the two different plants and then create new grafts and therefore new coral cacti. This is actually not as long a process as it seems. We can create several plantlets this way.
Potting and Repotting
Knowing when to repot is a tricky thing, as with other succulents. Many owners repot as soon as they buy the plant. They claim, and in many cases rightfully so, that the coral cactus is often sold in pots without drainage, with extremely compact gravel. In most cases, however, repotting can usually wait. Sometimes, the need doesn’t arise for a long time.
When repotting we can follow a simple method. Use an instrument to cut between the pot and the soil. Extract the root ball carefully. Observe it and trim away excess roots and dead roots, if need be. Later, repot the plant and make sure you use a pot with proper drainage.
The coral cactus is rarely rootbound in a pot. This makes repotting generally unnecessary. If it starts showing the telltale signs of too much rooting, then we may repot into a slightly larger pot.
There are some signs which can point us towards the need to repot. There are some obvious signs we can look for: water sitting on the soil and not going through and the obvious signs of an undernourished plant that is literally starving itself. It’ll be quite unusual to have to repot the coral cactus though.
Fertilizing the coral cactus is only necessary during the growing season. This is quite typical of other cacti and succulents. Most standard fertilizers will do. Some owners like to use a 10-10-10 liquid fertilizer, diluted to about ¼ strength (meaning 2.5-2.5-2.5). Fertilizing every two weeks should be a good frequency.
As with most succulents and cacti, the coral cactus doesn’t need to be fertilized during winter. Also note that the richness of the soil mix may make fertilizing unnecessary. Many owners prefer to steer clear from slow-release fertilizers or even granular fertilizers, since they can burn the plant itself.
The coral cactus may be attacked by the usual pests which target other similar succulents. These include mealybugs, scale insects and spider mites.
As ever, preventing pests is easier than having to deal with them. Overwatering is, as we’ve pointed out, a killer of succulents. The coral cactus is no exception. Too much water may cause rot and invite the appearance of pests.
If pests have appeared, using rubbing alcohol with a cotton swab will help take care of them.
When it comes to diseases, there are some things to take into account. First, there is powdery mildew. This may happen if the plant is enduring humid conditions and has very little air and ventilation. Although quite rare, if powdery mildew actually does appear, some owners like to dilute one tablespoon of baking soda into a gallon of water. They will then use this mix to apply on the affected surfaces.
Another problem to take into account is root rot. It will usually develop in the case of overwatering. This, as we know, is a killer of succulents and cacti. In this case, the best recipe really is prevention; we must apply a strict ‘soak and dry’ watering to our coral cactus.
To save a coral cactus from a case of root rot, we’ll have to let the cactus dry completely. We have to check that drainage is working correctly and tilt the pot to pour out all excess water. When the soil is totally dry we may want to attempt to repot the cactus.
We must then prune the roots and remove the dead ones. Then we may repot and thereafter apply a strict ‘soak and dry’ method. This may save our coral cactus. The best route, however, is always prevention.
Finally, fungal rots may develop in our coral cactus. This may happen because the plant has been damaged by cold. Pruning may sometimes be possible. The leaves will seem to have brown and mushy sections.
When it comes to pruning the coral cactus, we should be aware that this plant rarely requires it. There are, evidently, some exceptions. One such exception is when the cactus shows fungal root.
If the crest starts showing brown colors or a general softening, this may mean that there is rot to take care of. Some owners will immediately prune the damaged edges. If it’s possible to prune the damaged bits, then the coral cactus has a chance of succeeding.
When pruning, it’s essential to wear gloves. Most of the time, when manipulating the coral cactus, we want to wear gloves anyway.
Why is my coral cactus turning pink?
The edges of the crest of the coral cactus can actually change color. It will turn pink upon reacting to certain stress or stimuli.
How big will a coral cactus get?
The coral cactus can grow to about 9-15 inches (22-38 cm). Note that there are cases in which the coral cactus grows to around 36 inches tall (91 cm) and 24 inches wide (61 cm).
Does a coral cactus bloom?
It can but this is quite unusual. The coral cactus flower is very small and generally pink.
Is the coral cactus poisonous?
The coral cactus can actually be dangerous and is actually poisonous if ingested. Keep out of reach of children or pets.
The coral cactus can also produce a sap which may irritate the skin. It’s always best to handle the coral cactus with gloves, or to wash one’s hands after handling it. Also, ingestion of the sap is toxic and it’s also hurtful to the eyes. Don’t rub your eyes when handling this plant.
Is the coral cactus a succulent?
The coral cactus is not strictly a cactus. It’s actually two succulents joined together. Some owners call this, colloquially, a ‘franken-plant’.
More concretely, what goes on is simply that euphorbia lactea is grafted onto an euphorbia neriifolia or a cactus root stock.
How do they make the coral cactus?
The most important part of the process is the grafting. The grafting is basically accomplished by using a sharp knife. Such a knife must be thoroughly sterilized before the procedure. What horticulturists do is they basically take this knife and create a convex cut in the shape of a V at the base of the crest. They also create another V-shaped, concave cut, at the top of the root stock.
These two sections are put together by a skilled horticulturist. Twine is often used to hold the two sections together. They are also then covered with grafting wax. This material, as we know, is very useful to keep the newly cut tissue from drying out. Some experts also use materials such as rubber bands to hold the sections together. Eventually, the graft heals and the two plants are now a single plant, which we call a coral cactus.
Is the coral cactus a good beginner plant?
Even though the grafting and creation process carried out by horticulturists is relatively complex, the coral cactus is a simple plant to care for. Maintenance of this plant is not difficult and it’s therefore a good beginner plant.
Why is my coral cactus bending?
The coral cactus may be bending to the side because it’s only receiving sunlight on one side. Try to move the plant to a location where it may receive a more uniform and thorough supply of sunlight. Such a proper supply of light may impede a lopsided coral cactus.
What is coral cactus reverting?
The coral cactus is what some people call a ‘franken-plant’. As we examined throughout the article, this means that it’s the sum of two different plants.
Sometimes, the coral cactus reverts. Reverting means that the euphorbia neriifolia, onto which the graft was placed, starts redeveloping as an independent plant. The euphorbia neriifolia will usually shoot a second stem which goes up right next to the crown. If our coral cactus is reverting, we may either leave it be or remove this secondary stem.