If you are growing succulents, I suppose you have already come across some problems with your beautiful plants. One of the most common problems growers experience are the black spots on the leaves or even on the stems of their plants. Let me immediately clarify what causes these black spots. We know three main causes: sunburn, over-watering, and insects. In no way are black spots on leaves natural. As soon as you spot them, you know something’s wrong with your plants.
To assess what causes the problem, touch the leaves. If the black-spotted part is dry, it is most likely caused by sunburn. Maybe you placed your plants under super strong sunlight, or you simply have a succulent variety that prefers indirect sunlight or shade, and not knowing that you placed it under direct sunlight. What to do in this case?
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Removing the leaves with black spots is your only remedy
Unfortunately, there is nothing you can do to revive the dead leaves. Hence you should remove them. The next step is to bring the succulents in shade or indoor.s But always remember that succulents still need sunlight.
It is just important that you give them what they need, instead of simply placing them in the sunniest spot of your garden. Just as that wouldn’t help your skin, it doesn’t help the “skin” of succulents, and hence they get sunburned and develop black spots on their leaves.
Soft and sticky black spots suggest over-watering
If the blackish spots are gooey, over-watering is to blame. Again, there is nothing you can do to leaves with black spots except of removing them and freeing the plant. After doing so, transfer or repot the plant in the fast-draining soil mix for succulents (click here to check my favorite one on Amazon).
Then you should use the soak and dry watering technique. Pour water in the soil, not on the top of the plant. Then water the plant again only when the soil is completely dry. Depending on the climate or season, design your own watering schedule. Remember that black spots appear firstly on few leaves. This is a bad sign, and you have to act quickly. If you do not address the problem, the black spots will eventually cover the leaves and the whole plant.
The entire plant turning black is a clear sign of rotting
When all leaves or the entire succulent plant turns black, it is most likely a sign of the entire plant rotting from the root to the top. One of the main causes is again over-watering.
The best thing you can do is obviously to remove the plant from the pot. But make sure that the plant can still be revived. In some cases, if the rotting has progressed too much, you will not save a plant regardless of what you do.
Examine where the mushy parts are and remove them. You are lucky if the rotting happens on the top of the succulent. This means that you can re-pot the plant and save it. Remove all the rotting parts and get the healthy parts secured. Let them dry for a while before potting them in the fast-draining soil.
Can you save a succulent with the black stem?
In the worst possible scenario, you don’t only notice the blackening on the leaves but also on the stem of the plant. The parts of the plant with black spots become mushy, which is again a clear sign of excessive water in the soil, and in the plant.
The first thing you can do in this case is to assess whether or not some parts of the succulent remain healthy. If you find some, all hope is not lost. You can replant and revive the plant from the healthy parts. Cut all the black or rotten areas and throw them away. Make sure that you retain only the part of the plant that is completely healthy.
Insect causing black spots on succulent leaves
Though succulents aren’t as prone to insects as some other plants (think lettuce, tomatoes, and other vegetables you grow in your garden as a prime example), they aren’t completely safe either. And while sunburn and excessive water are the two main reasons of black spots on succulent leaves, you should check for the third possible cause as well–the insects.
The problem with insects is that it is often too small to spot, or it may attack the plant in night, when you sleep, and hence you never see the intruders, and may doubt whether they cause the problem. My advice: if you rule out over-watering and sunburn, insects are to blame. Let me explain.
If your plant is in shade, or it isn’t particularly sunny, and at the same time the soil is dry, you can rule out the two most common causes of black spots on succulent leaves. In such a case insects are to blame. It can be aphids (check aphids on succulents for more info), but it can be also snails, bugs, etc. If you aren’t sure you can simply try to move the succulent to another location (perhaps indoors), or you can use some pesticide (wither homemade or bought) as a prevention. Needless to say, I strongly suggest you to use home-made and ecological solutions.
Final thoughts
We know three main causes of black spots on succulent leaves. As you know now, you can identify sunburn and over-watering quite easily–depending on the structure of the leaves, as well as gauging the situation of your plant–where you placed it, how often you water it, etc.
When you rule out sunburn and over-watering, insects are typically to blame. I hope this article helped you learn how to deal with these problems, and that you will enjoy your succulent garden, and revive the plants that have black spots on their leaves. Good luck to you!
P.S. To learn the ins and outs of successful succulent growing, check my complete guide on growing succulents. Thank you!