A cactus is a hardy plant that does well without a lot of attention. However, repotting your cactus every now and then is an essential part of making sure your beloved plant stays as healthy as possible. So how can you tell when it’s time to repot your cactus?
You should repot your cactus if its roots are growing through the drainage holes, which signifies that your plant is root-bound and has outgrown the container. However, a withered or top-heavy cactus is also a sign that you should repot it soon. You should repot a cactus every 2-4 years.
The rest of this article will elaborate on when you should repot your cactus and the best ways to do so. Let’s get started.
1. When Roots Grow Through the Drainage Holes
Roots growing through the drainage holes of your cactus’s pot is a tell-tale sign that your plant needs to be repotted.
The roots of a cactus can only grow for so long in one container. After a while, your cactus will outgrow its container. And if it stays too long in a pot that is too small for its roots, the roots will grow in circles around the container until the root mass is bound together and cramped.
While this might not seem like that big of an issue, root binding is a significant problem that can cause adverse effects.
A root-bound cactus will have trouble distributing water and nutrients throughout the plant, which can negatively affect the plant’s health and even lead to death if not corrected in time.
Repotting is a quick and easy way to address a root-bound cactus. By providing your plant with a new container, its roots will have room to grow and unwind.
However, it’s best to repot your cactus before it becomes root-bound, exactly why you should stay proactive with your repotting habits and provide your cactus with a new container every 2-4 years. That way, you can prevent root binding and keep your cactus healthy.
To learn more about root-bound cacti, check out my article, where I discuss how you can tell if a cactus is root-bound and whether you should replant it: Do Cactuses Like to Be Root Bound? What You Need to Know
2. Your Cactus Has Grown Aerial Roots
Another sign that your cactus should be repotted is the growth of aerial roots.
Aerial roots are small, thin, branch-like roots that sprout from the parts of your cactus that are above the ground rather than within the soil. These roots are usually a light pink, brown, or white color.
A plant will grow aerial roots if it’s not getting all of its needs met in order to absorb carbon dioxide, water, and nutrients from the air. While the roots themselves are not harmful, they are a sign that you should make a few adjustments to your plant care.
One reason why a cactus might grow aerial roots is that it needs to be repotted. If your cactus is in a container that’s too small for its size, it won’t have enough access to nutrients in the soil to support the cactus.
While aerial roots can be caused by other issues as well, repotting is always a good idea if you notice the growth of these roots.
To learn more, I recommend checking out my guide on cacti and aerial roots. You’ll discover what causes the condition and what you can do about it: Why is Your Cactus Growing Aerial Roots? 6 Causes
3. Your Cactus Is Withering
A withering cactus is a sign that you need to repot it as soon as possible.
Your cactus is withering if it is gaining a yellow or yellowish color, appears shriveled, or is either too wet or too dry. All these indicate that your cactus is not doing well and can do with some environmental adjustments.
Again, if a cactus has outgrown its container, its roots will not have enough space to grow. And if a cactus has fewer roots than needed to support its size, it can experience some serious deficiency issues, as the roots will not be able to meet the plant’s nutrition and hydration demands. Withering can occur if these requirements are not adequately met.
While withering can also be a sign of over or underwatering, or even some cactus diseases like bacterial or fungal rot, it can also be a clear indicator that it needs to be repotted.
4. Your Cactus Is Lopsided or Disproportionate to Pot Size
Another sign that repotting is long overdue is when your cactus is disproportionate to its pot size or appears lopsided.
This is one of the easiest ways to tell if your cactus needs to be repotted. If your cactus is simply too big for its container, it will need a new one to stay healthy and access all the nutrients and hydration it needs.
However, while this is a simpler sign, that doesn’t mean the issue itself is simple. If your cactus has overgrown its pot, it needs to be repotted as soon as possible, so it doesn’t get root-bound.
5. It’s Been a While Since You Last Repotted Your Cactus
If it’s been a while since you last repotted your cactus, this is a sure sign you need to give your plant a new pot.
Time is one of the best ways to know when you should repot your cactus. As I mentioned before, the best time to repot your cactus is every 2-4 years. So if it’s been at least two years since your last repotting session, you should start sourcing for a larger pot before your cactus gets root-bound.
6. Your Cactus Has a Disease
If your cactus has a disease, repotting is a great way to rid it of the infection, promote healing through healthier root growth, and give it a new, clean space to thrive.
There are many cactus diseases out there, most of them being viral, bacterial, or fungal. While additional treatment is always necessary, repotting can provide your plant with a clean space to heal and grow free of contaminants in its previous soil.
Think of it as making your bed with clean sheets or cleaning up surfaces to prevent the spread of bacteria. While the disease will need to be addressed separately, repotting your cactus boosts the chances of successful recovery significantly.
7. Your Cactus Has Pests
Another sure sign that your cactus needs to be repotted is if it’s infested by pests.
Here are some signs that your cactus might have pets:
- Appears shriveled or withered
- Yellow or sickly parts
- Brown spots (usually a sign of spider mites)
- Swarmed by small flies (fungus gnats)
- Unhealthy, chewed-up leaves
- Scaly appearance
While pest infestations will need additional treatment, it’s always best to repot your cactus as soon as you notice any signs of pests. This will give your cactus a fresher environment and possibly free it from infestations that could have been in its previous soil.
If you’re repotting your cactus for reasons involving pests, you can mix in a little bit of cinnamon with the soil to work as a natural pesticide that won’t harm you or your plants.
Another thing you can do after repotting is to spray your cactus with a homemade pest control solution, which is cheaper and a more natural way to address the issue. I recommend mixing one part apple cider vinegar with one part water before spraying it on your plant to end the infestation.
Using these pest treatments immediately after repotting is also a good habit to practice in general, whether you have pests or not– just to be safe and take preventative measures.
Disclaimer, repotting due to pest infestation should be treated as an emergency, meaning you should start the process without wasting any time. Additionally, you should ensure you choose the right pot and soil before you repot your succulent.
How Often Should You Repot Your Cactus?
So we’ve talked about how to tell if your cactus needs to be repotted, but not when. So how often should you repot your cactus to provide it with the best possible care?
You should repot your cactus every 2-4 years to ensure it doesn’t overgrow its container and become root-bound. By sticking to this repotting schedule, your cactus will grow healthy provided all its basic requirements are adequately met.
Waiting too long to repot your cactus can cause nutrient deficiency issues and even promote pest infestations. As such, you should make regular repotting a habit to boost your cactus plant’s overall health.
Should You Repot a New Cactus After Purchase?
There is a common saying in the cactus community that you should always repot a new cactus after purchase. Is this really true?
You should always repot a new cactus right after purchase. This is a good habit to practice because standard nursery soil isn’t adequate for a cactus to stay in long-term. Repotting new cactus is also a good way to rid your cactus of any potential pests it could have obtained at the nursery.
Another reason to repot a new cactus immediately after purchase is to put it in a more suitable container, as paper or cardboard nursery pots are usually not meant for long-term use and will degrade over time.
And considering a new cactus will need to acclimate to a new environment, it’s best to ensure you get the ideal pot from the get-go. If unsure about the best pot for your new plant, don’t hesitate to ask the expert you are buying from.
How To Repot a Cactus
This section will elaborate on the exact steps you need to take to successfully repot your cactus without damaging the plant, as well as provide tips on how to make the process easier.
1. Choose the Right Soil
Before you start the repotting process, the first thing you want to do is choose the right soil.
Soil selection is one of the most crucial parts of repotting. Without the right soil, your cactus can face tons of drainage and nutrition-related problems that can negatively impact its health. This is why choosing the right dirt is important, especially a mixture specifically designed for cacti.
2. Select a Good Pot
Once you have the right soil on hand, it’s time to choose a good pot.
When repotting your cactus, it’s vital to make sure your pot is the right size. A good rule of thumb is always to make sure the pot is 10% larger than the cactus’s diameter.
From there, I recommend increasing the pot size by about 2 inches (5.08 cm) every 2-4 years, depending on how quickly your species of cactus grows, and its total size when fully grown.
While size is very important, it’s also critical to get the right kind of pot. Water drainage is one of the most important parts of plant care, as a lack of adequate drainage will lead to root rot and even drowning. You should always purchase pots with drainage holes at the bottom.
You can either buy a terracotta pot with drainage holes and a matching tray or keep your cactus in a plastic container within a more decorative pot, like a ceramic one.
The pot will work if it’s the right size, has drainage holes, and has something to catch the water leaking out.
3. Mix Soil With Vermiculite or Perlite for Drainage
The third step is to mix your soil with vermiculite or perlite for drainage.
These soil additives are great for making sure your soil has the ability to drain water correctly, which is good for cactus health, as they survive on little water, and too much water retention can cause a lot of issues. You can add one part vermiculite or perlite to one part soil.
4. Use Gloves to Gently Remove the Cactus
Once your soil and pot are prepared, the next thing you need to do is to remove your cactus from its current pot and move it into its new one.
For this step, it’s vital that you wear gloves. Doing this will help protect both you and the plant. Most cacti have sharp spines that can be painful to the touch, so it’s really important to make sure your skin is covered.
5. Hold the Cactus Inside the Pot and Fill With Soil
Once you’ve used gloves to gently remove the cactus and its roots from the current pot, now it’s time to transfer it to its new container.
What you don’t want to do is dig a hole in the pot and shove the cactus inside, as this can damage the roots.
The best way to go about doing this is to hold the cactus inside the new container as you fill it up with dirt. It can be tricky to do with only one set of hands, so it might be helpful to get assistance during this step.
As you fill in the soil, make sure to gently pat it down to make sure it’s firmly packed.
6. Water Your Cactus
Once your cactus has been correctly repotted, it’s really important that you water it as soon as you can.
Repotting is a necessary part of cactus care, but it can be a traumatic experience for the plant and cause it to go into shock, which is why it’s important to make sure it has access to plenty of water during the adjustment process.
When watering your repotted cactus, remember to avoid overwatering as it can lead to problems such as root rot. Ideally, you should repot when the cactus’ watering schedule is due. This ensures that the plant receives just the right amount of water needed.
Final Thoughts
Repotting is a fragile but necessary part of proper cactus care. However, it can be challenging to know when it’s time to repot your cactus.
If your cactus is root-bound, has sprouted aerial roots, is withering, is top-heavy, has pests or disease, or simply hasn’t been repotted for a couple of years, then it probably should probably be repotted.
Hopefully, this article has helped you better understand the repotting process and your cactus as a whole. By following these tips, you can successfully repot your plant and ensure that it lives a long, happy, and healthy life for years to come.
