Succulents have captured our collective hearts, brightening up our windowsills and adding fascinating colors and patterns to our gardens. Succulents are naturally highly resistant to the stresses of drought, heat, and the strong UV light of the desert environments they often come from. There are a huge variety of succulent plants from a myriad of plant families, making them very collectable and meaning that there are succulents suitable for every garden and home.
Despite this, succulents have a dark side. They can even kill. Many of the most common succulents we keep in our homes and gardens are actually very toxic. In nature these toxins are used as a sort of chemical warfare, to discourage animals from consuming them. In the human environment, however, these plants pose a serious threat to children and pets who may consume them without knowing the dangers. They also pose a danger to those taking care of them, who may be exposed to their toxic effects via sap splashing onto the skin, the eyes, and the mucous membranes. The following plants are some of the most common toxic succulents that are commonly grown in the home and garden.
18 Toxic Succulents To Avoid
African milk tree
The first on our list is Euphorbia trigona, the African milk tree. Used as thorny fencing and as a landscape plant in Africa, the African milk tree makes for an interesting yet dangerous houseplant. Behind the spines, this species as well as the other members of the genus Euphorbia are known for their highly toxic latex. It is very irritating to the skin, eyes, and mucous membranes and has been known to cause rashes and temporary blindness in even small amounts. If ingested the latex can cause serious internal injury, even organ failure and death.
Perhaps the most commonly grown succulent in the world is the jade plant, Crassula ovata. It is a very difficult plant to kill, thriving in drought, full sun to light shade, and poor soil. It’s shiny, succulent green leaves almost look edible, but appearances can be deceiving. Jade plants are toxic, from flowers to roots. Exposure to the sap can irritate the skin and eyes, causing itching and rashes. Ingestion of the plant can cause illness in humans and animals, causing gastrointestinal and neurological issues. Jade plant poisoning is common but usually not fatal, causing a relatively mild and temporary illness. If you have cats and dogs at home, worth being extra vigilant
Adenium obesum is an unusual succulent native to Africa and the Middle East and produces one of the most beautiful flowers in the plant kingdom. The plant grows on a large swollen woody base called a caudex, which serves as a giant storage organ to get them through times of stress. When conditions are right the plant draws upon these resources and produces brilliant crimson flowers, which has earned them the moniker ‘the desert rose.’ Their beauty is a deadly one, however, due to the presence of a class of toxins called cardiac glycosides. Cardiac glycosides are incredibly dangerous when ingested, causing gastrointestinal distress and heart issues. If enough of the plant is ingested this plant can be fatal.
Sansevieria, also called the snake plant or Mother-in-Laws tongue, is an extremely popular genus of house plants. They are well-known to purify the air and be nearly impossible to kill, making them the perfect houseplant for a beginner. They should also be kept away from children and pets, however, as they contain toxic saponins. Consumption of snake plant foliage or roots will cause gastrointestinal distress, including diarrhea, nausea, and vomiting. Because saponins are not well-absorbed by the body, however, poisonings are usually self-limiting.
Succulents of the genus Yucca are extremely popular landscape plants. Though they are not very dangerous plants, ingestion can cause vomiting and nausea due to the presence of toxins called saponins. These toxins are not well absorbed by the body, however, and usually poisonings are mild. Because saponins are easily broken down in high temperatures, they are used as a food source in their native range with the proper preparation.
Aloe is one of the most commonly used medicinal plants in the world. A handsome plant from the Middle East, Aloe is both eaten as a food, used as a medical ointment and supplement, and grown as a landscape plant. It can cause liver damage in large amounts, however, and can cause serious intestinal distress when taken orally in some people. Be very cautious when using raw aloe vera either externally or internally, as allergies to the plant are very common. It is also toxic to many animals, so keep your pets away from this one.
String of Pearls
Senecio rowleyanus has become a popular hanging houseplant, well known for cascading sprays of pearl-shaped foliage. The plant itself is quite toxic, however, and exposure to the sap can cause a rash while ingestion of the plant can cause more serious symptoms, like vomiting, nausea, and diarrhea. The plant also contains alkaloids that, when consumed in quantity or over long periods of time, can cause liver damage and ultimately liver failure.
Blue chalk sticks
Curio repens is a striking South African plant with a brilliant blue chalky color. It is very easy to grow and a popular plant in xeriscaping, growing well in dry soil and even taking shade. It is also quite toxic, however, containing pyrrolizidine alkaloids that are very toxic to the liver. Taken in large quantities or over large periods of time, these toxins can cause liver failure and death.
Some succulents are simply too dangerous for most people to responsibly grow. Euphorbia tirucalli is perhaps the most dangerous plant on this list and is certainly one of the most virulently toxic members of the Euphorbia genus. It is so toxic, in fact, that it should only be handled while wearing protective goggles and gloves. The milky latex is extremely irritating to the skin and mucous membranes and even more dangerous when there is contact with the eyes. The sap can cause temporary blindness, even in very small amounts, as well as intense irritation and swelling. The blindness can even become permanent if enough sap is present and the damage goes untreated. If the sap is consumed it can cause severe burns to the throat as well as cardiac arrest and death.
Alluaudia procera, is a strange and rare Madagascan succulent cloaked in a fierce set of spines. It is highly sought out by plant collectors, as it is both hard to find and an incredible statement plant in the garden. It can grow into a strange columnar tree up to 50 feet high, absolutely massive for a succulent, almost appearing like the tentacles of an octopus. Those seeking to grow this plant, however, should keep in mind that it is toxic. Fortunately, however, its thorny armor generally stops any unlucky animals from trying to take a bit of this unusual and poisonous plant.
Euphorbia lactea, known as the candelabra or coral cactus, is a species of Euphorbia from tropical Asia. It has become a popular houseplant but is remarkably toxic. Though it is used medicinally in its native range, the sap is caustic and can cause burns and rashes as well as serious eye damage. Ingestion is often fatal without immediate medical intervention, so keep this plant far away from anyone able to look past the spines long enough to try to eat it.
The panda plant, Kalanchoe tomentosa, is one of the cutest of succulents, covered in a downy fuzz with dark-colored accents. It is a common houseplant and is used as a garden plant in warm places, as it is quite drought tolerant and attractive. It is also toxic, however, like the other members of the genus Kalanchoe. It contains toxic cardiac glycosides, which can be fatal if enough is ingested.
Crown of thorns
One of the thorniest plants on our list is Euphorbia milii. This plant is both spiky and toxic, as the sap causes intense irritation and if ingested the plant causes extreme stomach pain, burns to the throat and mouth, nausea, and vomiting. Though the plant is not as dangerous to humans, it is fatal to most livestock and pets if ingested. This plant is found all over the world, as humans value it as medicine, as a pesticide, and as an ornamental plant. It has very showy red flowers and is extremely easy to grow, perhaps helping its popularity but also increasing the risk of poisoning.
Kalanchoe gastonis-bonnieri, more commonly known as the donkey ears succulent, is a Madagascar native known for its large and striking leaves, dotted with an interesting red pattern. It is a distinctive and unusual plant well-loved by plant collectors, but it is also toxic. The whole plant contains bufadienolides, a kind of chemical called a cardiac glycoside that can cause depression, stomach upset, heart problems, and eventually death.
String of Dolphins
The colourfully named string of dolphins succulent, scientifically known as Curio peregrinus, is a common houseplant that does remarkably well in the bright, indirect light of our homes. It is a hybrid of the string-of-pearls succulent and Curio articulates, also known as the hot dog plant. The sap of this plant is irritating to the skin and the plant is very toxic to the liver if consumed, often causing serious illness and death if enough is eaten.
Mother of thousands
True to its common name, mother of thousands, Kalanchoe daigremontiana is a plant with great reproductive potential. The margins of each leaf are lined with miniature versions of the adult plant, which grow large and drop off the plant to establish new colonies elsewhere. It is so good at making copies of itself that it has spread from its home range of Madagascar across the world, populating tropical areas by escaping human cultivation. The entire plant is very toxic due to the presence of a poisonous steroid that can cause, among other things, heart failure. Though it is a common plant, it certainly is not a safe one.
This unusual plant is a hybrid between two species of the genus Crassula. It is an easy plant to care for but is mildly toxic, causing gastrointestinal distress, ataxia, and brachycardia. It generally does not lead to serious illness, however, just a serious amount of discomfort and potentially a visit to the emergency room. It is a good idea to keep this plant out of the reach of curious children and pets, lest they are deceived by its interesting appearance and try to eat a piece.
Baseball plant, Euphorbia obesa
The baseball plant, Euphorbia obesa, is a charming succulent hailing from the Karoo desert in South Africa. It is so charming, in fact, that it is highly sought after by collectors and is endangered in its native range due to habitat destruction and poaching. It has a dark side, however, and like the other members of the genus Euphorbia it secretes a milky white latex that causes severe skin and eye burns. Ingestion of this plant is dangerous, though not as much as other species in the genus, and can cause burns and stomach damage.
- Are succulents poisonous for humans? Yes, there are many succulents that are poisonous to humans. As previously mentioned, Euphorbia is one genus of plants with toxic members. The latex of the aloe plant can be irritating to the skin and mucous membranes if it makes contact for an extended period of time. Many cacti also contain substances like chlorophyll that can cause vomiting and diarrhoea if ingested. Furthermore, many succulents are poisonous for pets, especially cats. If you own a cat or dog it is important to ensure that your plants are out of reach to avoid potential poisoning.
- How do succulents affect humans? Succulents vary in how they affect humans. Some, like the string of dolphins and mother of thousands, cause only mild irritation to the skin and do not present much danger unless ingested or mishandled. Others, like baseball plants and aloe vera latex, can be dangerous if they come into contact with the skin for too long or if consumed.
- How poisonous are succulents? Again, as previously stated, succulents vary in their toxicity. Some, like the string of dolphins and mother of thousands, are only mildly toxic and not a danger unless ingested or mishandled. Others, like baseball plants and aloe vera latex, can be dangerous if they come into contact with the skin for too long or if consumed.
- How deadly is aloe vera? Aloe vera is not deadly unless consumed in large quantities. The latex, which has a high level of toxicity and can cause severe skin irritation and burning if it makes contact with the skin for too long, causes poisoning. Though many people use aloe vera as a home remedy, they should take care to ensure that they don’t consume it or that they don’t leave it out where pets or children could eat it.
- Can aloe vera kill you? No, aloe vera cannot kill humans if consumed in normal quantities. It can lead to vomiting and diarrhoea but is only dangerous when ingested in large amounts over a long period of time.
- How do you know if a succulent is poisonous? Any member of the succulent family (Aizoaceae, Cactaceae, Crassulaceae) can be poisonous if consumed. The best way to keep your plants safe is to ensure that they are out of reach of pets and children. Also, make sure that you know what type of plants you have so you can look up specific toxins if need be.
- Are succulents safe for pets? As previously stated, many succulents are poisonous if consumed by pets. It is important that people who own pets know which plants are unsafe and remove them from the home or keep them out of reach of cats and dogs.
- What kind of dangers do cacti pose to humans? Cacti are only dangerous when they come into contact with the skin for extended periods of time. This causes burns and irritation in the area, which can be painful. They also contain substances like chlorophyll that can cause vomiting and diarrhoea if ingested. Additionally, if people consume cacti in large amounts over a long period of time it can cause internal damage.
- How dangerous are cacti to cats? Cats are more susceptible to the dangers of cacti than humans. They can eat them without being affected but will be severely burned by the plant’s toxins if they consume too much over a long period of time.
- Is it bad to have succulents in the house? Succulents can be dangerous if ingested or mishandled but pose little danger as long as they are kept out of reach of children and pets.
- How harmful are peas plant? The peas plant is mildly toxic to humans. If it makes contact with the skin for too long or if consumed in excess it can cause nausea, vomiting, diarrhoea and a burning sensation on the lips and mouth.
- Is pencil tree plant poisonous? The pencil tree plant, or Euphorbia tirucalli, is mildly toxic if consumed. It causes irritation to the lips and mouth as well as nausea and vomiting when ingested in large amounts for a long period of time.
- What about the Mexican hat plant? How poisonous are they? Mexican Hat, or Magonia pubescens, is moderately toxic to humans.
Poisonous Succulents - Final Thoughts
Succulents are often beautiful and easy to grow, but they can be dangerous. If anyone you know has ingested any of these plants, or if you have a pet or child you think has been exposed to these plants, please seek medical attention immediately. Some of these plants are potentially deadly when consumed, even in small amounts, and others can cause long-lasting disability.
If you wish to keep these plants you will need to take some precautions. As a plant and animal lover, you want a peaceful co-existence among your closest possessions – your succulents and pets. When pruning or propagating these plants it is best to use gloves (in the case of the Euphorbias, eye protection is necessary). Wash pruning implements after use, to both protect the tool and prevent exposure to sap. If you have pets or small children, keep these plants far out of reach or in terrariums. It is also best to keep the most dangerous of these plants out of areas near paths or where they are easily accessible to the public, as simply brushing against them can release sap and cause an exposure.