This post may contain affiliate links. If you click one of these links and make a purchase, I may earn a commission at no additional cost to you. In addition, as an Amazon Associate I earn from qualifying purchases.
Having a cactus in your home could be a lot of fun, and many people think that they look cool. Generally, taking care of a cactus isn’t going to be hard, but this doesn’t mean that problems can’t pop up.
It can be especially worrying if you discover that your cactus is turning black. This is certainly not normal, and you’re going to want to try to figure out what’s going on quickly.
Why would a cactus turn black, and is there anything that can be done to turn things around? Keep reading to learn about why this might be happening to your cactus.
Once you’ve read the information below, it’ll be easier to formulate a plan about what to do. So long as you’re proactive, there might be a chance to save the cactus.
1 – Freezing Temperatures
It’s no big secret that cacti prefer warm temperatures and dry environments. If your cactus was exposed to freezing temperatures, then it’s possible that this is the cause of the cactus turning black.
Sometimes extreme cold exposure can cause a cactus to become injured. These injuries from the cold weather exposure might show up as black spots that look kind of damp.
When the cactus has a chance to dry out a bit, the parts of the cactus that are black might become brittle. It wouldn’t even be unusual for sections of the cactus to fall off at this point.
The best thing to do is to protect your cactus from cold temperatures. These plants aren’t meant for cold weather, and you’ll need to place them somewhere safe if you know that cold weather is coming.
2 – Fungal and Bacterial Infections
Cacti will sometimes turn black in response to fungal or bacterial infections, too. There are actually many different types of fungal infections that you’ll need to look out for.
Conidia is a type of fungus that can infect your cactus through the water. Ascospores travel through the air to infect plants.
Fungal infections might take weeks to start showing symptoms, and this means that it’s possible that your cactus could have a fungal infection even if it isn’t showing signs yet.
Bacterial necrosis is something that can cause cacti to turn black. This is something that is a unique cacti problem, and only certain types of cacti need to worry about bacterial necrosis.
Crown rot is a disease that can impact many different types of plants. This is another type of fungal infection that you need to worry about.
It happens when a fungus in the soil infects your cactus, and it’s more likely to occur if you make the soil too moist by watering the cactus too often. Sadly, crown rot is almost impossible to remove from the soil, and this means that the prospects for your cactus surviving might be bleak.
Younger cacti are more likely to die from crown rot than older established cacti. It’s still possible that adult plants might not make it, though.
How to Fix These Issues
Fixing these issues will be easier said than done in many cases. When your cactus has already started turning black, there’s a chance that it might be too far gone to save it.
Even so, it’s worth doing what you can to try to save the plant. There’s a possibility that you’ll be able to turn things around.
First, you should isolate the cactus that is turning black so that it doesn’t spread an infection to other houseplants. Next, you’re going to want to go ahead and remove damaged arms to try to stop any infections from going any further.
You’ll need to cut deep so that you can get rid of all of the rotten parts that have been infected. Doing this should give the cactus a chance to survive.
You’re also going to need to change the soil because the soil could be thoroughly infected. Get fresh soil and ensure that the soil has plenty of nutrients that the cactus will need.
After this, you’ll just have to keep a close eye on your cactus. It’s possible that you might need to cut the cactus again if you notice any more black or rotted spots.
Hopefully, your cactus will pull through and will get a chance to grow healthy again. It isn’t always easy to nurse a cactus back to health once it has been infected this badly, but there’s certainly a chance that things will work out fine.
Try to Avoid Future Problems
You know more about taking care of the cactus once you’ve discovered that it has a problem, but there is no guarantee that the cactus will survive. This means that the best way to keep your cactus in good health is to try to prevent infection from happening in the first place.
Being especially mindful of what can cause a cactus to get infected with bacteria or certain types of fungi will help you out. Always be careful not to water your cactus too much since that can create conditions where fungi can thrive.
Doing your best to care for the cactus the right way is going to be the key to keeping things safe. You want to give your cactus a nice warm environment where it can thrive so that it won’t experience problems like this.
Even when you do everything right, it’s still possible that you could encounter problems. Being that some fungi travel through the air, you’ll still need to keep a close eye on your cactus to spot any problems.
Observe your cactus and try to recognize anything that might be wrong as early as you can. Early detection of issues can make it easier to remedy the problem, and you don’t want to wait until parts of your cactus turn black.
Of course, you can also choose to treat your cactus and other houseplants with fungicides on a semi-regular basis as a precautionary measure. Many people do this when they live in areas where fungal infection issues are common.
So long as you’re doing your best, it’s likely that everything will be fine. Just keep caring for your cactus to the best of your abilities.