In the world of garden design, cacti and succulents are often used interchangeably. But the truth is that cacti and succulents are distinctly different, and both plants have benefits in your garden.
As you would expect, cacti grow upright, while succulents tend to lean against walls or fences. Also, cacti are smaller and hotter in temperature, while succulents are larger and cooler.
Cacti and succulents are fascinating, and it has become quite the trend these days to care for these plants.
There are many types of cacti put there, and they boast interesting features such as big flowers, interesting fragrances, etc.
Cacti and succulents are often referred to as the same, and while this is not exactly incorrect since both are closely related, there are some differences between cacti and succulents.
Table of Contents
What Is A Cactus?
A cactus is a plant with only stems. Cacti either don’t have leaves, or their leaves modify into thin, spiky spines.
Cacti also feature areoles on their stems, and these areoles are where flowers, spines, or even hairs on the cactus grow.
Areoles are the most defining feature of cacti since many other succulents can feature spines without areole, but if the areole is present, the plant is classified as a cactus.
What Are Succulents?
Succulents refer to the broad group of plants that have developed to resist conditions with water scarcity.
They have fleshy leaves, stems, and a root system where they can store water to resist dry conditions.
The fleshy leaves on succulents consist of gelatinous liquid sap, which is their main water reserve, and they use it to resist dry conditions.
The surface of the leaves on the succulents is shiny and waxy, which is how the leaves prevent water loss.
How Are Succulents Biologically Different From Cacti?
To simplify it, all cacti are succulents, but not all succulents are cacti. Cacti or Cactaceae are a family within succulents that feature cacti with a stem and a spine.
All cacti also feature areoles, which are small, round bumps on the stem of the cactus. Areole does not do not feature on every succulent, making them the distinguishing feature for cacti.
Other than that, succulents comprise a fully developed root system, stems, and fleshy leaves. Cacti only consist of stems and roots.
Most cacti do not feature leaves, while non-cactus succulents often feature thick, fleshy leaves that store water and nutrients. Cacti, instead, have thin and spiky spines on their stems which function as the leaves.
These thick fleshy leaves in succulents also take part in photosynthesis and are the main generator of food and energy for the plant.
On the other hand, only the stem participates in photosynthesis in cacti. Only the stems conserve water in cacti, while the leaves, roots, and stems all can conserve water in other succulents.
Cacti usually require around 6 hours of light exposure to grow and develop. At the same time, succulents can survive without a lot of light, and prolonged exposure to the light can actually damage the plant.
Many common plants look like cacti and are often mistaken for cacti. All of these plants are succulents; they are not classified as cacti, though. Some of these plants include:
The aloe plant has large, fleshy leaves that contain sap. Their surface is waxy, and the edges of the leaves are covered with spikes.
The aloe plant also produces flowers, and its sap is known to have multiple health benefits.
Despite its deceptive appearance, the aloe plant is not a cactus and is a different type of succulent.
Haworthia also consists of thick, fleshy leaves sometimes covered with spikes on their edges. The leaves grow upward as rosettes.
They resemble aloe plants as well and can be easily mistaken for cacti. Haworthia is also a succulent that is not a cactus.
The Yucca plant has stiff and narrow leaves which are pointy with sharp tips. Their edges are saw-like similar to the Aloe as well.
The Yucca plant has bell-shaped flowers, which can be white or cream in color depending on the species of the plant.
Some yucca plants also bear fruit consumed in different parts of the world, such as Southwest America and some parts of Mexico.
They are similar to cacti because of their sharp leaves and resistance to drought conditions. However, the Yucca plant is a non-cactus succulent.
Beargrass bears white flowers which are clustered and emit a foul odor. Beargrass may have a grassy appearance, but the long, pointy blades are not grass.
They are, in fact, leaves that are coming from a single stem in a rosette formation. When the plant dries out, the leaves become sharp and spiky and can easily injure a person. Despite the spiky leaves, beargrass is succulent but not a cactus.
Agaves are short-stemmed, rosette-forming plants with leaves that grow in rosettes. Some agave species can grow up to 3-feet tall in dry conditions.
Yuccas are a type of agave as well. All parts of the agave plant can commonly be consumed by people in the United States and some parts of Mexico.
It offers nutrition to many different animals, including sheep that eat the sappy leaves, hummingbirds, and insects that suck the nectar from the flowers of the agave. Agave is also not a cactus.
An Ocotillo resembles a cactus immensely, but it is a succulent and not a cactus. They have spiny leaves, often turning gray and disappearing in very dry conditions.
However, ocotillos bloom quickly after it rains. Depending on how much it rains in the region, ocotillos may lose their leaves at least three times a year. They bear blood-red flowers which appear in clusters at the tips of the ocotillo stems.
These plants also form rosettes with their leaves and grow in super dry conditions. They don’t resemble cacti very much, except their thick, fleshy stems and drought-resistant features give them away as such. However, the Echeveria is also a succulent but not a cactus.
The Aizoaceae resembles a type of cactus but are a different type of succulent altogether.
Lithops, or stone plants, are part of the Aizoaceae family and feature small, rounded leaves that look like small stones. Lithops are also not cacti, even though they closely resemble them.
Cacti and succulents both feature many physical features that may make them resemble each other closely.
However, there is often a difference between the features of the two. Some of these features include the following.
Cacti and succulents both bear flowers, depending on the season. Common cactus flowers include Queen of the Night, a fragrant flower that suddenly releases its scent at night to attract pollinators. Peanut cactus also produces orange flowers in summer that cover a large part of the stem.
On the other hand, the Ice plant is a non-flowering succulent that features thick fleshy leaves and vibrant, daisy-like flowers.
Echeveria also features gorgeous flowers in rosettes of leaves. These flowers are either orange or bright yellow. A specie of the Echeveria, the Black Knight, produces black-hued sepals enclosing gorgeous, bright red flowers inside.
Both cacti and other succulents also bear fruit which is consumed by people all over the world. Fruits on cacti and other succulents are also easily recognizable because of their distinct features.
Prickly pear is an example of common cactus fruit. Dragon fruit also grows on a cactus known as Hylocereus.
The agave plant, which is a succulent but not a cactus, also features different, interesting fruits on their plants. These fruits are sweet like honey, and the darker they get, the more they resemble the taste of maple syrup.
While most cacti and succulents’ defining features are thorns and spikes, not all cacti and succulents feature thorns and spikes. Common spineless cacti include peyote, astrophytum myriostigma, and mammillaria hernandezii.
Lithops or stone flowers are examples of succulents that do not have spines.
These thorns and spines are necessary for dry conditions to help the plant store water and survive. However, many of these plants contain fleshy leaves and stems that store water instead.
Classification Hierarchy For Succulents And Cacti
All cacti are succulents. However, succulents do not form any classification subgroup. Cacti, on the other hand, are classified.
Identifiers Of A Cactus
The following features can identify a cactus:
Areoles are the bumpy ridges on the stem of a cactus where flowers, leaves, and spines grow. Hairs are present on the surface of the areolae, which give them a wooly appearance.
Most areolae become inactive after they have produced the spine or flower that they were meant to produce.
The most iconic appearance of cacti is long, fleshy stems. Cacti use these stems to store water for long periods, and this stored water helps the cacti survive in drought conditions.
Some cacti are covered in tubercles, which are small bumps. Other cacti are either smooth or ribbed.
The stems of the cacti are the primary organ that performs photosynthesis, and the chlorophyll contained in these cacti is what turns them green.
The spines present on the cacti are its leaves. They are sharp and spiky to protect the cactus from predators. Some cacti may also have flat, fleshy leaves. However, these are specific to certain areas.
Cacti flowers are usually brightly colored and grow in clusters or single flowers.
Most cacti have shallow roots and do not reach very deep underground for water. Taller cacti have larger roots for extra support.
Classification Of A Cactus
There are two main Kingdoms that all living beings are divided into, the Plant Kingdom and the Animal Kingdom.
Cacti are part of the Plantae kingdom since it is a plant and not an animal. Since cacti are vascular plants, they belong to the Phylum Tracheophyta and the Anthophyta division since they are flowering plants or angiosperms.
Furthermore, they are a part of the Magnoliopsida class and the Caryophyllidae subclass. This is because cacti are insect-pollinated plants that contain dicotyledonous seeds.
Furthermore, the Kingdom Plantae is divided into the order Caryophyllales, where most succulent plants belong, and the Cactaceae family. The order Caryophyllales also consists of other horticultural crops such as rhubarb and spinach.
The Cactaceae family is divided into at least 150 different genera, and amongst them, most cacti belong to the Cactoidea subgroup.
The other two classifications include Opuntiae and Pereskieae. Oprunitiae consists of cactus plants such as the prickly pear, and the rose cactus is amongst the few species that belong to the Pereskia subgroup.
Lastly, the cactoids and Opuntias contain at least 2000 different species of cacti that can be found all over the world.
All of these species contain the main features of a cactus, such as a fleshy stem, areolae, and needle-like spines instead of leaves. They also develop shallow roots.
Many succulents do not belong to the Cactaceae family, such as Aloe Vera, which belongs to the Xeroids class of plants. Other succulents, such as the Angeline Stonecrop, are part of the Crassulaceae family.
Succulents on their own do not have a classification and can belong to many different families and classes in the entire Kingdom Plantae.
Cacti, on the other hand, have a proper biological classification. So even though all cacti are succulents, there is no biological classification that will separate cacti from other succulents in other families in the Kingdom.
Similarities Between Cactus And Succulents
There are many similarities between cacti and succulents that are not cacti, which is basically why the terms are used interchangeably.
First of all, most succulents have fleshy stems, just like cacti. These stems store water to help the plant survive in severe conditions.
The stems of many succulents are similar in texture to those of cacti since they are waxy and fleshy to prevent water loss.
Many succulents are also adapted to surviving in extreme climates such as deserts and perpetually cold areas, just like cacti.
In fact, the fleshy leaves, the stems, and the roots of the succulents are used to store water for energy generation, just like cacti do with their stems. Both types of plants can easily survive in drastic climates.
Succulents also often consist of sharp, spiky spines instead of fleshy leaves, just like a cactus. These sharp spines are used to keep predators away from both plants. Examples of succulents that consist of sharp leaves include Yucca and other Agaves.
Most succulents also have shallow roots like cacti.
Cacti and succulents need slightly drier soil than other plants to grow properly. It is easy to overwater both types of plants since they store a lot of water in their leaves, stems, and roots.
Cactus and other succulent plants all produce flowers as well. These flowers are usually brightly colored to attract pollinators and have distinct scents.
For example, the Queen of the Night flower grows on cacti and gives off a beautiful fragrance at night. Similarly, the starfish flower cactus also has a distinct, rotten smell and is succulent.
They also bear fruit. Some of the most commonly consumed fruit from succulents and cacti include the prickly pear, the dragon fruit, and even Aloe! Yes, sap from aloe leaves is consumed in many areas and is said to be excellent for improving digestion.
Difference In Care
Cacti and succulents have been tamed as houseplants as well and are absolutely wonderful to keep in the house.
Many people are slowly becoming more and more enthusiastic about succulents because of their unique shapes and also because they are so easy to care for!
Most cacti and other succulents have similar care tactics. However, there are some key differences in the care we give to cactus and other succulents since they do not belong to plants’ same category or family. Here is how to care for cacti and succulents:
Both cacti and succulents require similar soil composition to thrive. People who own these plants must ensure that the soil mix is completely dried before watering it.
Succulents have adapted to survive in extreme conditions without readily available nutrients and water, so they do not need constant vigilance to survive.
Line the bottom half of the pot with stones or gravel to ensure that the soil mixture drains out completely before watering the plant again.
Succulents usually should not be watered more than once a week. Of course, this could differ depending on the climate conditions that you are growing the plant in, but even in very hot and dry climates, succulents can easily survive up to a week without being watered.
It is easy to overwater both cacti and succulents. Overwatering can lead to rotting, fungus, and the plant’s eventual death. Therefore keep the water sparse.
Most cacti are adapted to surviving in very hot environments like desserts. Therefore they are very resilient and usually do well even in extreme sunlight.
Some succulents, however, are not well adapted to very hot conditions. Therefore, they can die from overexposure to heat, especially when placed under direct sunlight.
Therefore, you must try to keep other succulents in slightly shaded areas. You can also move them to different parts of your house to see where they thrive the most and keep them there.
Alternatively, you could keep your succulents outside but bring them in the shade when the temperatures rise!
Both cacti and succulents need ample light to grow since both types of plants survive through photosynthesis.
However, many succulents that are not cacti cannot survive in the excessive warmth that comes with a lot of light and die out.
Succulents, therefore, often need less light than cacti, and some may even grow better in darker conditions. Before getting a succulent that is not a cactus, you should talk to an expert about how much light it would need to grow.
Predators For Succulents And Cacti
Despite their clever mechanisms to keep predators away, even cacti and other succulents fall prey to many predators.
They contain thick, juicy sap and many succulents also bear juicy fruit, which animals love to consume. Here are some of the most common animals that prey on cacti and succulents:
Many desert animals feed on the juicy, sap-filled leaves and stems of cacti, especially spineless ones. These animals include herbivores like camels and the jackrabbit.
Camels love to eat prickly pear pads and even stems from different cacti. Their palates are hard enough not to be injured by the sharp spines on many cacti.
The spines are not their main source of food, though; camels love these plants’ fleshy stems and succulent leaves instead.
Jackrabbits belong to the hare family and survive on the water from fleshy cacti and succulents when there is none nearby.
Even some omnivores like the Coyote like to feed on cacti and succulents. Coyotes survive in the desert by eating the fruit of cacti, such as prickly pears.
They can even eat the stems and thick leaves of succulents when there is no fruit available.
Many birds find food and shelter in different cacti and succulents. One such example is the Gilded Flicker birds, which live in the Saguaro Cactus and eat its sweet fruit.
They drill holes in these cacti with their sharp beaks, which can often hamper the structure of the cactus and sometimes may even kill it.
The screech owl also lives in the holes made by other birds in cacti, such as the Saguaro cactus. However, the screech owl does not feed on the leaves or the fruit of any cactus.
Common birds like woodpeckers can also poke holes in cacti in people’s homes. It is important to repel these predators since household cacti are not as sturdy as those in the wilderness.
Rodents such as the woodrat and squirrels also often survive on the seeds and fruits from different cacti.
They also often find shelter by digging burrows right beneath the base of a cactus which can damage its roots.
Most rodents will even feed on the sharp, spiny cacti and their fruit without any apprehension, making them the archenemies of most cacti in deserts.
Common rodents such as mice and rats can also attack cacti. They can bite off entire chunks from the leaves of succulents and their stems which can kill the plant if it continues.
Therefore, you need to set up rodent traps and repellents to prevent rats from eating your cactus.
Many different types of bugs and pests can attack cacti and succulents. These include mealybugs that leave behind a wooly, white webbing on the cactus.
Scale insects also attack cacti and leave a white substance behind. Many different pests can hide under this substance and feed on the cactus’s nutrients without anyone knowing!
Spider mites, gnats, and beetles also attack cacti and feed on their nutrients. It is essential to get rid of these bugs before they wreak havoc on your plant.
Cacti and succulents are more resistant to pest attacks than most other plants, so they will probably stay healthy for a long time if you take care of them.
Common Problems With Cactus And How To Fix Them?
Cacti are very resilient plants. However, they still need care from their owners to thrive. There are some common problems that most cactus and succulent owners face, and some of them include the following:
Overwatering and Underwatering
Cacti have evolved over thousands of years to be able to survive in extremely hot and dry conditions and need as little water as possible.
So they can make the most of very scarce reserves of water too. However, cacti and succulents are very easy to overwater because of this cool feature. When you overwater a cactus, it can lose its structural integrity and even begin to rot.
On the flip side, if you are afraid of over-watering your cactus, you may end up under-watering it instead. Underwatered cacti can also make the plant susceptible to diseases and even kill it.
Most cacti and succulents require watering once a week only. However, many plants have specific requirements.
Opuntiae requires less water than most other cacti, and Parodies require moist soil. Therefore, do your research on the plant you get.
You need to find the perfect balance of watering for your cactus. Experiment for a few weeks with optimal times to see how well the plant grows and continue the habits that work best.
There are hundreds of pests out there that can attack the stem or leaves of the cactus, including red spider mites, scale insects, mealy bugs, or the larvae of certain insects.
These pests can rot the plant’s stems and even give them a bad odor. Some of these pests also attack the roots and weaken the base of the plant.
If pests are not dealt with promptly, they can kill the plant.
To get rid of pests, you can use a garden hose to spray them away or make a mixture with dish soap and rubbing alcohol.
Use the mixture on the pest-afflicted areas of the plant for a few days, and there will likely be a difference.
Overwatering cacti can cause mold to grow on the stems and leaves of the cactus. This mold can also attract insects such as the fungus gnat, which can hover over the cactus. The mold can eventually kill the plant as well.
To prevent your cactus from molding, you can give it optimum water and refrain from overwatering.
If the cactus is already growing fungus, you can carefully remove the moldy part with a sharp blade so it will be healthier when the plant grows again.
Make sure the succulent or cactus is not growing in bad soil conditions. Most regular soil mixes do not work well for cacti and cause root rot. Succulents and cacti require soil that is drier than normal soil.
So be specific with the kind of soil you use for the cactus. Also, do not make use of organic manure or compost. Dry fertilizers work best for cacti and succulents.
Wrong Pot Size
The wrong pot size can stunt the growth of your cactus and make it difficult for the plant to survive for long.
Make sure the pot you select for your cactus is the correct size. If the cactus grows tall, you will need a deep pot to support the more complex root system.
Most small cacti and succulents have shallow roots and do not require deep pots.
You can even use a grow bag to grow your cacti and succulents instead of clay pots since grow bags are more adjustable.
Whether you use a pot or a grow bag, it must contain a proper drainage system to dry the soil aptly. If the cactus spends too long in moist soil, it is dangerous to be over-watered.
Non-Ideal Light and Heat
All cacti and succulents and different requirements for light. For example, many cacti can survive under direct sunlight and scorching heat but most other succulents cannot.
Overheating the plant can scorch different parts of the plant, hinder growth, and even kill the plant eventually.
It is important to research the type of succulent you have and how much heat and light it would need for optimal growth.
Too Many Pesticides
Sometimes, when pest attacks get out of control, it is important to use pesticides on your plant. However, you should only do this if none of the milder methods for removing the pests work.
Under no circumstances should you regularly use pesticides on your cactus since it can react with sunlight or something in the soil and scorch or rot the plant.
Most cacti have developed self-defense mechanisms that help them prevent pest attacks. However, if the attack gets out of control, you can use alcohol, dish soap, and even diluted vinegar to ward off the bugs. Most of these methods are very useful.
In conclusion, they can grow almost anywhere. Most cacti and succulents require little to no soil, though some do need a little.
They require lots of sunlight, so plant them near a window or in a sunny spot. Water them sparingly, but regularly.
If you notice the roots starting to rot, either decrease how often you water them or give them more sunlight.
Also, guard against pests. Many cacti and succulents have very flat leaves that easily snag on clothing and human debris.
Plants like aloe and snake plants, though, have rounded leaves that tend to fall off easily, making them less prone to dirt and pests.
Cacti and other succulents are very interesting plants, and caring for them is a wonderful hobby. All cacti are succulents.
However, all succulents are not cacti. There are many similarities between the two, along with some key differences.
It is essential to keep these differences in mind if you want to be a loving owner of these fascinating plants! With proper care and nurturing, you will learn everything there is to know.
Frequently Asked Question (FAQ)
Is aloe vera a cactus or succulent?
Aloe vera is succulent because it stores water in its tissues and requires no soil to grow. However, this plant has the appearance of a cactus.
Which cactus is edible?
The prickly pear cactus is edible. It has a mild, sweet flavor and can be enjoyed in desserts, jams, jellies, and syrups.