What Are Succulent Plants?

As I was doing the weekly soak of my mini succulent garden the other day, I stopped dead in my tracks as the question occurred to me: what are succulents?  I’ve been loving caring, planting, and watering them for years, but since grade school, I haven’t really looked up what exactly they are.

Succulents are plants that have specially adapted themselves to be able to live through periods of either water or sun drought. They’re able to store water so that they can make it through times when water is not in abundant supply, and some when sunlight is tough to get to. 

Water drought is the most common, but we’ll talk more about that in a second.

christmas cactus succulent
A christmas cactus that blooms annually (out of bloom pictured).

What’s cool about succulents is not only can they store water when needed, but they’ve adapted so that they can completely stop growing and go dormant when the ecosystem is too harsh for them to grow.

Succulents come in a variety of shapes, sizes, and adaptations. Many have root systems that are extremely shallow and fibrous, and act almost like the plumbing in a house. Many succulents also have root systems that form new hairs the moment they sense moisture in the area. This allows the root systems to swallow up much moisture as possible.

A pretty awesome accommodation if you ask me!

Where can succulents be found?

Succulents are actually found all over the world in a variety of climates. Most people envision succulents only surviving in very hot, very dry desert regions covered in sand, but this is not always true.

Certain succulent species, such as the Medinilla plant (found in the Philippines), grow in the partial shade, very commonly in cracks and crevices within tall trees.

Jade plant succulent built for humid regions such as jungles
Jade plant succulent built for humid regions such as jungles. The Jade plant is a leaf succulent.

Many succulents can be found in dry semi-desert regions where they can still find shade and prosper outside of direct sunlight and extreme heat.

Surprisingly, succulents can be found on snowy mountainsides as well.

It’s counterintuitive but actually makes sense once you think about it.

Although cold, the snow actually helps act as an insulator for the plant. It protects it against the abrasive, chilly winds.

It also helps nourish the plant once the snow melts and drips down so that the shallow, well spread out roots can absorb the moisture quickly.

Why do succulents thrive in hot dry climates?

Short answer: evolution. These plants have evolved to withstand and thrive in environments that would kill most other plant species.

Their evolution has allowed them to store water either in their root systems, stems, or their leaves.

Think of a succulent plant as the camel of the Plant World.

When water does fall, the dense root systems and thick leaves absorb that moisture and hold on to it. They take only the minimum that they need to survive and keep the rest for the prolonged periods when moisture is hard to come by.

Succulents that store moisture underground in their root system have adapted this accommodation so that they are less susceptible to fire and animals. Many of these succulents shed their leaves if it doesn’t rain for long periods of time, then grow back once their water source is more sustainable.

Many succulents have very hearty stems and leaves that are thick and hold moisture there.

It’s very common for the leaf succulents to actually live underground with only their tips exposed to the sun. This helps prevent moisture from escaping and makes it hardier.

Can succulents survive indoors?

Most succulent plants can absolutely survive indoors. they do great with partial sunlight areas, predictable temperatures ( most typically on the warm side). In areas of the world where the winters are harsh and the temperatures drop below freezing, it’s actually preferable to keep succulents indoors.

Frost is the enemy (as is overwatering, direct heat, and several other hazards that we will talk about in a later article).

The frost is especially harmful due to the amount of moisture that most succulents retain in their leaves, roots, or stems.

When this moisture freezes, it’s game over for the plant.

Several species can come back if the freeze is not prolonged. If it is, it can be a lot more difficult for your plant to be nursed back to health.

If you live in an area with harsh winters and you have plans or don’t have storage space indoors, and outdoor greenhouse can often be a great medium.

Almost as bad as frost is exposure to too much water.  While several succulents do well with humidifiers, very few of them do well when their soil is too wet.  Overwatering succulents is one of the most detrimental things you can do for your plant.

It’s almost always better to underwater than overwater.  Overwatering can lead to darkening tips of the leaves, root-rot, and an overall unhealthy succulent.

For this reason, it is essential to put it in a container or pot with proper drainage and put porous additives in the soil.  Succulents like drainage!!!

Putting pumice or sand at a ratio of 1:4 with normal potting soil will typically do the trick, but specialized succulent soil is also available at your local hardware/gardening store.  Use it when in doubt.

Are all succulents cacti?

All cacti are succulents, but not all succulents are Cacti.

cactus areole with spines growing out of the bud
A picture of the areole region of the cacti with sharp spines growing from the small bulb. Some areole are hard to see with the eye.

Cacti are known as stem succulents. they’re able to retain enormous amounts of water because, for many, their climate is so dry for so much of the year.

Of course, there are certain types of cactus that are indigenous to Jungle regions. Many of them use their roots to attach themselves to other plants (as described by the Medinilla above).

Instead of growing thick to absorb and retain water (it is a humid jungle after all), many jungle cacti grow very flat. They do this because under the jungle canopy light can be a scarce resource.

The flats stem allows them to absorb all the sunlight they need to survive.

You can tell if a succulent is a cactus by a couple telltale signs.

  • Cacti often have ribbed stems to allow them to expand when water is plentiful needs to be absorbed, but also contract when its resources need to be utilized during dry periods.
  • Cacti also have small pod-like buds for its spines and blooms. These are called areoles.
  • Cacti also have very fibrous root systems. If it’s a desert cactus, this allows you to absorb as much moisture as possible while it’s plentiful. If it’s a jungle cactus, this allows it to attach itself to other plant life.

Why do Cacti and Succulents have spines?

Almost all cacti have spines, but only some succulents have spines.

Some spines are very thick and sharp while others look almost like hair or wool.

Most people think that the thick, sharp spines act only as a defense mechanism. Although they do defend against potential predators, the main purpose of the spines is to drip moisture down to the base of the plant just above the root system.

stem succulent with sharp spines
This stem succulent has sharp, pointy spines that direct water dripping from the stem to the roots so it can continue to feed, even when water is scarce. It will shut down and go dormant if the conditions stay too dry and hot for too long.

The wool-like spines offer a very different type of protection; one from the elements.

stem succulent cactus wooly spines
The wooly spines on this cactus succulent help protect it from excessive sun and frost.

These are commonly seen on succulents that grow in climates of either extreme heat or extreme cold and frost.

These types of spines give protection in the form of shade in sunny regions and on the first of frost over an extreme cold.

In areas where frost is prevalent, the hair like spines are the first to thaw and drip the moisture to the root system where it can then be absorbed into the roots and stored in the stem.

Thank you for reading this article! Please don’t hesitate to share this with friends if you found it helpful.

Hewitt, T. (1993). The complete book of cacti & succulents. Montreal: Readers Digest Association (Canada).

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