Cactus arms falling off can actually have a few different causes whether it’s from direct damage from something impacting it or from poor care.
In any case, you’re here because you want to know why your Cactus arms are falling off and what you can do about it.
So here’s why this can happen and what you can do from this point.
Underwatering
Many people know cacti are drought tolerant plants, after all, they’re cacti.
Although these succulents can go longer without water than most plants, they still do need water from time to time.
Failing to water regularly can result in your cactus drooping or wilting which can offset the weight enough to where the cactus arms can fall off.
Water and nutrient loss leading to overall dehydration of your cactus is no Bueno as it is.
While this is unlikely to happen from missing watering here and there, if you have just completely neglected your cactus and not given water in a while, or even worse never watered then this is likely the cause.
You should be watering whenever the soil has completely dried up as soon as you notice, but also not before.
Overwatering
Overwatering a cactus is one of the most common reasons for cactus arms falling off since overwatering can lead to ineffective roots and eventually root rot.
Root rot is a major reason for plant leaves falling off and your cactus is unfortunately no exception.
With that said, overwatering on it’s own can take it’s toll on your succulent by starving the roots of oxygen which in turn means less water and nutrients are passed to the cactus itself.
This results in some or all of the following symptoms.
- Cactus drooping or wilting
- Cactus turning yellow
- Cactus turning brown or brown spots
- Cactus turning black
- Cactus turning soft or mushy
- Cactus arms falling off
- Stunted growth
- Root rot
- Standing water in the soil
Overwatering can even mimic the symptoms of underwatering since the roots become ineffective and it will be similar to your cactus not receiving water, because eventually it won’t be.
In any case, if you overwater for long enough, you can expect root rot will cause all sorts of damage to your cactus resulting in the arms falling off.
Just picture a tree with rot near the base, and how much easier you think it would collapse compared to if it was very healthy.
This is why it’s very important to never overwater your cactus as good things never come from it.
Too much heat
Although cacti are known to be quite resilient to extreme temperatures, and they are, sometimes it can be too much for them.
It’s still entirely possible for a cactus to get sun scorch damage when left in extreme heat for too long, although rare it can happen.
Sun scorch can cause your cactus to get dry and crispy which can result in the succulent not being able to support itself and you may see the arms fall off.
While this is unlikely to happen compared to more common causes, it’s still a real possibility if you’ve been growing outdoors during heat waves or just temperatures that are just too extreme.
Physical damage
If you have checked all of the above and everything seems to be in order, then odds are your cactus arms falling off is caused by physical damage rather than a care issue.
This is especially true if your cactus just looks happy and healthy and there isn’t signs of rot like being mushy or have unusual discoloration.
If you’ve been growing outdoors, it’s possible that something has either fallen onto the cactus or something carried by the wind was pushed into it.
It could even be an animal has shown up and bumped into it or climbed onto it which can certainly happen if your yard isn’t protected.
However if you’ve been growing indoors, this is only likely to happen if your cactus has been placed below things that could fall and have enough weight to damage the cactus arms.
Or if you placed it into a cramped area and have accidentally pushed the cactus into something else or vice versa.
Lastly, it could be caused by shipping issues, especially if you bought your cactus online as I’m sure you’re aware of how much neglect can happen when buying things online unfortunately.
No matter how it was physically damaged, this is the best case scenario as this means your cactus is still healthy and there is something that can be done.
How to propagate cactus arm
Assuming your fallen cactus arm is still healthy, one of the best things you can do moving forward is to propagate it!
Although you can propagate an unhealthy cactus arm, it’s not really advised since the success rate is lower and you may run into issues further down the line.
This is really for fallen cactus arms that appear healthy or only slightly damaged.
So if you were wondering how do you regrow cactus arms?
The answer is through propagation.
So here are the steps needed to successfully propagate your cactus arm so you can regrow a full healthy cactus!
Let the cactus arm heal
Whenever a cactus arm has fallen off, it was separated from the main part of the plant and thus there is some damage that needs to dry and callous before propagating.
Failing to let a cutting dry or heal before planting can cause it to become vulnerable to rot and other issues.
So let your cactus arm dry and heal for at least a few days to a week before moving forward.
Set up the soil
Now you should get some fresh soil selected, ideally a cactus and succulent soil mix that drains well to prevent watering issues in the future.
Also make sure you select a container that’s the right size if that’s how you’re planning to grow.
Now you can wet the soil to let it get somewhat moist without it being soaked since the roots will be very shallow or close to non existent at first and you don’t want standing water.
If the roots aren’t deep enough to reach the water, the water is going to be sitting there for a while unless the soil drains really well so water pretty shallow at first.
If you’re curious how deep cactus roots grow, you should check out my article highlighted.
Plant the cactus arm
Shortly after watering the soil, go ahead and plant your cactus arm slightly into the soil so that it can hold firm and the roots will have room to grow.
Be sure not to pack in the soil too tight around the cactus so that the roots will be able to breathe and grow well.
Now place the container somewhere that gets plenty of bright indirect light and you will be good to go!
Over the next several weeks you should have some healthy roots growing in abundance and you will be that much closer to regrowing from a cactus arm.