Black Spots on Succulents: The Ultimate Guide to This Common Problem

Have you recently noticed Black Spots on Succulents? Probably you are wondering the reasons why this is happening and what can you do to get rid of them to help your succulents get in better shape.

If you are looking for answers to this problem, then you’ll find this guide very in-depth,  informative, and helpful. Everything you need to know about it: identification, reasons, cure, and how to prevent them.

Black spots on succulents are a widespread disease, and by following a simple screening you’ll be able to identify them early, give your plants the proper treatment, and ultimately save their life!

So let’s get started!

Six Causes for Black Spots on Succulents

Generally speaking, succulents are quite easy to grow and care for, given the fact that they are hardy plants. That being said, likewise all other plants, they are subject to various pests and diseases.

Black spots on succulents are mainly caused by 6 reasons.

  1. Pests
  2. Fungus, Rot & Water Warts
  3. Sunburn
  4. Frost
  5. Overwatering
  6. Trauma

Before moving to each one of these reasons, here is a rule of thumb: If the black spots are dry, it’s most likely caused by sunburn. You can remove the individual leaves and keep your plants inside. They’ll still need sunlight, but make sure that they’re not getting too exposed.

Related: Succulent stem turning Brown

If the black spots are soft and mushy, it’s probably from over-watering. You can remove the leaves with spots on them and then repot the plant in the fast-draining soil mix for succulents.

When you see black spots on the leaves you need to act quickly to prevent the spreading of them on the whole plant.

Reason #1: Pests

Pests on Succulents

Black spots on succulents could be a sign of large or small pest infestation. A variety of pests, from tiny aphids to big snails, slugs, grasshoppers, and caterpillars feed on succulents, as well as larger animals. These last ones, like birds, mice, possums, deer, or kangaroos take big chunks, whereas small insects and bugs will only make tiny marks on the leaves and stalk, causing the black spots on your succulents.

Unfortunately, once a succulent leaf is damaged or scarred, the only way to hide the spot is to remove the leaves with spots.

Aphids and mealybugs secrete a sticky fluid that sticks to the plant, making it look worse and they like to hide underneath the new and soft leaves, preventing them to grow and ultimately causing them to die.

Ants can be harmful too: they thrive on the sticky sap aphids and mealybugs make. Ants spread and ‘farm’ these pests as they produce a sugary honeydew which ants collect for their own benefit.

They tend to protect aphids and mealybugs from predators such as parasitic wasps or ladybugs.

Slugs and snails will poke little holes into succulent leaves that will then heal into brown or black spots. Because they hide under pots and rocks and they only come out at night, it’s quite hard to spot and catch them.

Cure for Pests

Let’s take a look at how the most common tiny pests can damage your plants and how to get rid of the infestation that is causing unattractive black spots on your succulents.

Aphids
Aphids on Succulents

Aphids reproduce very quickly. That means you have to act fast to save your succulent from being devoured by these tiny pests.

It’s good to know that you can easily get rid of aphids by using pyrethrum-based sprays. You can easily spot them by looking at their color: they are usually green, black, brown, and sometimes orange.

Solution: if you are dealing with a small colony, it’s easy to kill them with a toothpick and wash off the plant. It’s a good practice to keep the infected plants separate from the others, to prevent your whole garden to get infected.

If you’re interested in learning more about other common plant pests, check out our article on Aphids and how to control them.

On the other hand, when dealing with a larger infestation, it’s essential to use pesticides. However, keep in mind that pesticides can kill lots of beneficial insects and pollinators too, so it’s better to use them as a last resort. That’s why it’s best to use the pesticide at night when the good insects aren’t flying.

You can treat black spots on succulents with Neem Oil Spray, natural cold-pressed oil from the seeds of the Neem tree, although isn’t that effective as many aphids can survive it quite easily.

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Mealybugs
Mealybugs on Succulents

Black spots on your succulents can also be caused by Mealybugs. Getting rid of them can be quite challenging since these pests have a wooly protective cover making them resistant to common pesticides.

They have an amazing ability to hide in the unexpected and narrowest places like between stem and leaves, nested in dried-up leaves, under pots, and tables.

They can even hide in debris around the plant and lay their eggs (up to 600) out of sight but close to the plants so when the little nymphs hatch, they don’t have far to crawl.

This is why detecting them early and isolating them is the best practice. It’s also important to keep clean not only the pots but also the whole area around them.

Solution: if you happen to find a few bugs, it’s easy to squash them with a toothpick. Next, pull out the infected leaves and thoroughly check around the plant to see if there are any bugs left.

Once you have detected and isolated the infected plant, it’s crucial to keep an eye on it for several weeks, just to make sure there aren’t any other outbreaks.

Another possible scenario occurs with a large mealybugs infestation: in this case, it’s necessary to spray the plants with a 70% rubbing alcohol or isopropyl solution with multiple applications. To completely get rid of these tiny pests it’s necessary to kill and wash off every single one

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If you’re interested in learning more about other common plant pests, check out our article on mealybugs and if they are harmful to human beings.

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Ants
Ants on Succulents causing black spots on succulents

Ants can be an indirect reason why aphids and mealybugs are appearing, causing black spots on your succulents. The reason why ants spread and ‘farm’ these pests is to collect their sugary honeydew. Ants also protect mealybugs and aphids from predators such as parasitic wasps or ladybugs.

Removing ants is not an easy task, given their numerosity and efficiency. Usually, the common pesticide only targets the workers, whereas killing the queen, who lays millions of eggs in the ground can definitely be much harder.

Solution: you want to make sure to get rid of the queen one possible way is with the borax and sugar recipe, although is not the most effective method. The best way is to keep the ground clean and spray any ants with a pyrethrum-based solution.

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Slugs and Snails on Succulents
Slugs and Snails

You will also notice black spots on your succulents after slugs and snails have munched on the tender parts of the plant, causing holes.

Eventually, the plant will start healing itself, leaving behind brown or black spots, unfortunately.

Solution: One of the best (and green) ways to get rid of them is to set up a beer trap: they will find it, drink it, and ultimately die.

Reason #2: Fungus, Rot & Water Warts

Black spots on succulents could also be caused by a fungus infection, rot & warts from over-watering. When this happens, usually you’ll notice round black spots on your plant, especially in a humid climate.

Solution: If you live in a high-humidity area you should only water your plants once a week to prevent shriveled leaves. In case you wonder, spraying the leaves with water doesn’t do any good because succulents are unable to absorb water that way.

You also want to make sure to use a succulent potting mix or any other mix that drains well. Heavy potting mix that holds onto the water will only make the infection worse.

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If you notice the root, stem & leaves turning black and gooey there isn’t much that you can do. The only thing you can do is to cut off the rotting part and plant it as a cutting.

Reason #3: Sunburn

Another very common reason for black spots on succulents is sunburn. Of course, succulents love the sun, which is one of the important components of their healthy growth. However, too much sun can also harm them, causing dry and patchy black spots.

Different succulents have different sun tolerance, but most of them will suffer in temperatures higher than 104 degrees Fahrenheit (40 degrees Celsius).

Succulents can react differently to extremely hot temperatures and can show different symptoms. Some may drop leaves, some can collapse in a heap of mush, and many will get obvious dark spots. As I mentioned before, the spots won’t disappear until the plant grows out of the wounds itself.

Solution: It’s possible to prevent sunburns by simply putting the pots in the shade during the hottest hours or if they are too heavy to move by covering them with an umbrella or a sunblock shade cloth.

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The good news is that it’s possible to save a sunburnt succulent by removing the burnt leaves from the plant.

During the following days is a good idea to expose the plants to the morning sunlight only for three to four hours. This way your succulent has a chance to heal from the burns and to adjust to more sunlight in the following days.

Reason #4: Frost

Dark spots on succulents can also appear as a result of frost damage. These plants, apart from some hardy varieties,  don’t tolerate extremely cold weather and can even die from it.

Solution: If you notice black spots on your succulents due to frost, simply remove the affected leaves and make sure the remaining leaves are in good shape.

It’s crucial to protect your plants with frost cloth if you live in an area where the temperature drops below 32 degrees Fahrenheit (0 degrees Celsius) or if you can,  can be a good idea to protect your indoor plants.

Reason #5: Overwatering

Overwatering your succulents can also be very damaging: these little plants don’t need much water and not as often as you might think. This is because their leaves and roots have the ability to store water for surviving in extreme weather conditions, giving them a more swollen or fleshy appearance than other plants, a characteristic known as succulence.

When succulents get too much water their leaves, stems, and roots start to swell up and eventually burst, causing black spots.

The leaves appear soft and mushy, almost translucent. If overwatering continues, they will start to rot turning to a dark brown/black color.

Solution: The good news is that there are still some things you can do to save your succulent.

First and foremost you should stop watering to allow your plant to dry out for a week or more. Make sure to always feel the top of the soil with your finger before watering again.

Secondly, you need to remove the damaged leaves and make sure the roots are still healthy by removing the plant from its pot and re-plant it in new dry soil.

If the roots are already mushy, that means they are dead, as well as the entire plant, unfortunately. You can still retain anything that looks green and viable, let it dry for some days, and propagate these cuttings by placing them in a new and well-draining potting mix.

Reason #6: Trauma

Scratches and puncture marks cause black spots on succulent leaves and often come as a result of poor handling of the plant, especially during repotting. And when a succulent is scratched or punctured, dark spots can form on the leaves.

Solution: Unfortunately, you cannot do much to remove these spots. All you can do is wait until the plant grows out of the damaged area.

FAQs: Black or Brown Spots on Succulents

1. How do you get rid of black spots on succulents?

Unfortunately, black spots on succulents won’t go away. Once a leaf or stem is damaged, the only possible thing to do is to remove the affected parts.

If you deal with dry and patchy spots caused by sunburn, you can remove the individual leaves and keep your plant indoors where indirect sunlight hits. If the spots are mushy and the plant is overwatered, you can remove the damaged leaves and repot your succulent in dry soil.

2. What causes brown spots on succulents?

Usually, brown spots are caused by sunburn and, although they don’t really harm your succulent, they won’t fade and will leave a permanent mark on the leaves.  It can happen when you move the plants from indoors to outdoors placing them in direct sun after being indoors for a few months.

The damaged leaves will eventually fall off as new baby leaves will grow in their place. Keep in mind that small baby plants, or newly propagated plants, are more susceptible to sunburn than mature plants.

The best thing you can do is to move the pots to a shadier place or, if you want to leave your plants under the sun, make sure they are well acclimatized to the heat by slowly increasing the sun exposure and are protected by a shade cloth to help diffuse the sun rays.

Check out this very informative video for more info!

Final Thoughts

There you go, everything you need to know about black and brown spots on succulents! Hope this article helped your research on this matter and answered all your questions, but feel free to leave a comment or share your knowledge on this topic in the section below.

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