How to Plant and Care for Coral Cactus Plant


Updated: 08 Nov, 2023

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Despite its misleading name, the coral cactus (Euphorbia lactea ‘Cristata’) isn’t a true cactus. It’s a combination of two distinct succulent species, grafted together to form this captivating, otherworldly plant. The upper, frilled section belongs to the Euphorbia lactea family, while the green “stem” (or rootstock) originates from Euphorbia neriifolia.

Once fused, these two Euphorbias form the coral cactus. Depending on the specific Euphorbia lactea variant used, the crest’s color can range from green to blue-grey, or even whitish-green.

The coral cactus has gained popularity as a houseplant, thanks to its striking appearance and low-maintenance nature. However, it’s important to note that, like all members of the Euphorbia genus, the coral cactus produces a latex sap that is considered toxic to both pets and humans. So, exercise caution when bringing this unique succulent into your home.

Read also: Gerbera Daisies Plant Care & Growing Guide

Botanical Name Euphorbia lactea ‘Cristata’, Euphorbia lactea x neriifolia 
Common Name Coral cactus, crested Euphorbia, crested elkhorn, crested candelabra plant, candelabra plant 
Family Euphorbiaceae 
Plant Type Succulent 
Mature Size 1-2 ft. tall (indoors) 
Sun Exposure Full, partial 
Soil Type Sandy, well-drained 
Soil pH Acidic, neutral, alkaline 
Bloom Time Spring, summer 
Flower Color Pink, purple 
Hardiness Zones 10-11 USA 
Native Area Africa 
Toxicity Toxic to pets, toxic to humans

What is a Coral Cactus?

The coral cactus, a cultivated variety of Euphorbia lactea, is indigenous to Asia, and primarily found in India. In its natural habitat, this spurge grows tall and exhibits a shrub-like form. It is a popular choice for ornamental purposes, often cultivated as a houseplant. It’s worth noting, however, that the coral cactus contains a toxic milky latex.

Scientifically known as Euphorbia lactea crest, this succulent takes on a fan-like appearance and is essentially two distinct plants merged into one through grafting. At its base, a Euphorbia neriifolia serves as a stem, while the upper part is a Euphorbia lactea. Despite originating from different succulent species, they seamlessly integrate into a single entity following the grafting process. Typically, this plant remains relatively petite, reaching heights of about 9 to 15 inches.

What distinguishes this succulent and draws the admiration of many houseplant enthusiasts is its unique appearance. Resembling its namesake, the top of the plant boasts undulating and frilly formations reminiscent of a beautiful piece of coral. The coloration is just as diverse. While the bottom of most coral cacti tends to be green, the top can showcase shades of white and may vary between purple, green, ruby, white, or yellow.

Coral Cactus Care

Caring for a coral cactus is fairly uncomplicated, though it deviates somewhat from the typical care of desert cacti and succulents. This unique Euphorbia hybrid is more adaptable to partial shade compared to its counterparts, and it also necessitates more regular watering. Furthermore, due to the manual grafting process that creates this succulent, traditional propagation methods like stem cuttings, division, or seeds are not viable. To propagate new coral cactus plants, you’ll need to employ the grafting technique.

  • Light:
    For optimal growth, the coral cactus thrives in ample light. When cultivating it indoors, select a spot that receives several hours of direct sunlight. If growing it outdoors in more intense light, opt for a partially shaded location. Remember to regularly rotate your plant (especially if it’s in a container) to prevent uneven growth.
  • Soil:
    To prevent overwatering and waterlogged soil, opt for a lightweight, well-draining soil mix enriched with plenty of perlite and sand. While cactus and succulent soil is tailored for these plants and offers excellent drainage, you can also create your own blend at home. Simply combine equal parts of potting soil, perlite, and sand.
  • Water:
    Unlike some of its close relatives in the Euphorbia family, the coral cactus isn’t as drought-tolerant. It should not be allowed to completely dry out and does best when watered once the top 2 to 4 inches of soil have dried. However, don’t fret if you occasionally forget to water, as it can recover from short periods of drought.
  • Temperature and Humidity:
    This Euphorbia thrives in warm, arid conditions, making it well-suited for indoor cultivation. It can also be grown outdoors year-round in USDA zones 10 to 11. For growers in colder climates, consider cultivating it outdoors during spring and summer, then transitioning it indoors for the cooler autumn and winter months. Avoid subjecting the coral cactus to temperatures below 60 degrees Fahrenheit (15 degrees Celsius) to prevent shock to the plant.
  • Fertilizer:
    While not a heavy feeder, the coral cactus can benefit from light fertilization during the spring and summer. Apply a fertilizer specifically formulated for cacti and succulents once a month until the fall, then cease applications until the following spring.

Potting and Repotting Coral Cactus

Because these plants are grafted, they seldom, if ever, outgrow their containers. Nevertheless, it’s advisable to repot them every few years to offer fresh soil and, if necessary, provide a larger pot. Wait for the spring or summer months when the plant is in its active growth phase to carry out the repotting, as this will help prevent the plant from experiencing any undue stress or shock.

When Will My Coral Cactus Bloom

Coral cacti (Euphorbia lactea ‘Cristata’) are not known for their prominent or frequent blooming. They are not typically grown for their flowers. Instead, they are valued for their unique, sculptural appearance. If a coral cactus does happen to produce flowers, they are usually small and inconspicuous.

If you are specifically interested in growing a succulent for its blooms, you might want to consider other succulent varieties known for their more prominent and colorful flowers, such as various species of Echeveria, Aloe, or Sedum. Keep in mind that even with these succulents, the timing and frequency of flowering can vary depending on factors like species, growing conditions, and care.

Common Pests and Plant Diseases

Be vigilant for typical indoor plant pests such as scale, mealybugs, spider mites, and aphids, as they can potentially infest this Euphorbia. If you spot any pests on your plant, promptly separate it from your other plants and manually remove visible pests using an alcohol-soaked cotton swab. For more severe infestations, consider using neem oil or insecticides as a treatment. Additionally, be mindful of the potential for root rot, which typically arises from overwatering conditions and can affect coral cacti.

How to Graft a Coral Cactus

Since the coral cactus doesn’t occur naturally, propagating this striking plant from cuttings or seeds isn’t possible. Instead, grafting is the method used if you have the appropriate succulents. To initiate the grafting process, you’ll need healthy specimens of both Euphorbia neriifolia and Euphorbia lactea.

Starting with young plants is advisable, as they tend to have higher success rates. It’s typically easier to begin with the Euphorbia neriifolia. Using a sterile knife, create a “V” shaped incision in the plant and remove the top portion. The Euphorbia lactea will fit into this “V” shape. Next, cut the lactea in a shape resembling an arrowhead, ensuring it snugly fits into the opening of the Euphorbia neriifolia. There should be no gaps, as this could lead to the development of a fungal infection.

Wearing gloves, apply grafting wax to the connecting surfaces. As it dries and the plants merge, use twine to secure them tightly together. After 2 to 3 weeks, inspect the plant to determine if successful grafting has occurred. In some cases, this process may take up to a month to fully integrate.

Common Problems With Coral Cactus

Apart from the occasional encounter with common houseplant pests and diseases, tending to the coral cactus is generally straightforward and trouble-free. However, there are a couple of typical issues to keep an eye out for, such as yellowing and the development of brown spots on either the rootstock or the top crest of the plant.

Yellowing:
If your coral cactus is exhibiting a yellow hue, it’s likely a sign of overwatering. While these succulents prefer more regular watering compared to some other Euphorbias, they still need to be allowed to dry out between waterings. They should never be consistently kept in damp soil conditions. If you suspect overwatering, it’s advisable to promptly repot your coral cactus with fresh, dry soil.

Brown Spots:
Brown spots can manifest in two distinct forms—either as soft, mushy spots or as hardened, ‘crispy-looking’ areas. Of the two, the soft, mushy spots are more concerning and often indicate some form of rot or fungal infection. As a first step, it’s recommended to examine the roots of your plant to rule out root rot. If root rot is not the cause, then it’s likely a fungal infection, in which case removing the affected area is the best course of action.

Hard brown spots are less worrisome and can sometimes be scars on the plant’s surface from previous wounds that have healed. They can also result from sunburn, which may occur if your plant is abruptly moved from a shaded area to an intensely bright location.

What is a Coral Cactus plant?

A Coral Cactus is a unique succulent created by grafting Euphorbia neriifolia and Euphorbia lactea.

How do I care for a Coral Cactus?

Provide ample light, use well-draining soil, water when the top soil is dry, and avoid overwatering.

Can I propagate a Coral Cactus from cuttings or seeds?

No, propagation is done through grafting since it doesn’t occur naturally.

Is the Coral Cactus toxic to pets and humans?

Yes, it contains a toxic latex sap harmful to both pets and humans.

Why are there yellow leaves on my Coral Cactus?

Yellowing is often a sign of overwatering. Allow the soil to dry slightly between waterings.

How do I deal with pests on my Coral Cactus?

Isolate the plant, manually remove pests, and consider using neem oil or insecticides for severe infestations.

When and how should I repot my Coral Cactus?

Repot every few years with fresh, well-draining soil, preferably in the spring or summer months.

Will my Coral Cactus bloom?

Coral cacti are not known for prolific or showy blooms; they’re usually grown for their unique appearance.

Conclusion

The Coral Cactus (Euphorbia lactea ‘Cristata’) is a captivating and distinctive succulent, created through the grafting of Euphorbia neriifolia and Euphorbia lactea. While it requires specific care, including ample light, well-draining soil, and cautious watering, its striking appearance and low-maintenance nature make it a popular choice for many plant enthusiasts.

It’s important to note the presence of toxic latex sap, necessitating careful handling. Additionally, due to its grafting origin, propagation differs from conventional methods. Overall, the Coral Cactus is a unique and intriguing addition to any succulent collection.


Mary Lloyster

Mary Lloyster

Mary, the ultimate oracle of indoor gardening! With years of experience and a flourishing indoor expo, Mary has become our go-to expert for all things related to house plants and indoor gardening. Despite her background in Political Science, Mary has discovered a delightful way to blend her full-time job with a touch of relaxation through indoor gardening. Now, she eagerly shares her wisdom and experiences with our readers on a daily basis. If you have any inquiries about house plants, indoor gardening techniques, or caring tips, don't hesitate to leave a comment for Mary in the designated section below!

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