Should Cactus Be Repotted? Why and When?
Perhaps you have cacti that have been growing in those lovely and cute small planters. I love them, but they are not the best for them. Indeed, without you knowing, your cactus is already suffering. You need to take action now!
Repot a cactus when 1) the roots start coming out of the container, or 2) they fill the whole planter, 3) after a heavy pest infestation, or 4) to propagate a heavy mother plant. After repotting, avoid 1) immediate watering, 2) fertilizer, and 3) direct sunlight.
You might not like the idea of repotting your prickly collection, but it is an inevitable part of gardening. Besides, your cactus would appreciate it, especially if its growing condition is becoming stressful. When? You will know why if you keep on reading.
Why Should I Repot My Cactus? 5 Reasons
Repotting cactus will give more growth space, allow more room for roots, and provide a fresh growing medium that ultimately stimulates healthy growth. Newly bought cacti need repotting to avoid contamination of pests and fungi on their existing medium.
Although most cacti species are slow-growing, repotting them is essential mainly for their growth. Here are the reasons why the cactus should be repotted.
1- Give More Growth Space
As the cacti grow, it is natural for them to overgrow their container, especially if they are tiny at the start. It uses up more space around the inside until it reaches the wall of the pot. In this case, its growth will be constrained, and the ability to produce more pups will be reduced.
A slow-growing cactus planted in a regular size container will outgrow its pot after 2-3 years. At the same time, a fast-growing cactus in a standard-size container will outgrow it in just a year or two. Cactus that exceed its pot need repotting to provide more space for its growth and allow the plant to produce as many offsets as it wants.
2- Allow More Room For Root Growth
Roots get stressed when they are crowded in a small volume. Promote the growth of cacti roots by 1) loosening them up, 2) trimming them down, and 3) transferring them to a larger pot where roots can freely spread and grow.
Cactus that develop vigorous root growth will tend to form a ball of compacted roots. When roots get overcrowded, nutrient absorption becomes difficult, and growth will slow down.
3- Provide Fresh Growing Medium
After several years of growing in the same container, it is vital to repot the cactus to a fresh growing medium. Indeed, after a few years, the growing medium might lose its drainage capability and become harmful to the plant due to the decaying of organic matter.
The organic constituents of cactus soil mix deteriorate over time, affecting the plant’s growth. When a substrate has worn out, it will likely breed pests/insects and molds, causing the soil mix to smell odorous. This scenario is harmful and will result to root rot.
Furthermore, incorporating peat in your medium will make the substrate dense and compact within a couple of years. In this case, the drainage rate of the cactus soil mix will become poor, increasing the possibility of overwatering.
4- Stimulate Healthy Growth
Cacti that tend to be unhealthy and have stunted growth for a long time can benefit from repotting. Indeed, I noticed over the years that repotting a cactus awakens it from its dormant state, stimulating active development and growth.
If you find your cactus not growing even if it’s their growing season, it may be due to its potting medium lacking nutrients. Try repotting the unhealthy plant to a new substrate to trigger new growth. Cactus from dormancy would love a new substrate to boost new root formation and healthy stem growth.
5- Inhibits Spreading Of Pests
Cacti that are severely infected with pests or diseases should be first treated and then repotted. Indeed, it is not uncommon for some pests to also hide beneath the soil surface. Hence, removing such pests from the cactus is not a sure guarantee of pest eradication.
Pests such as scales, mealybugs, and mites infest cactus and get into their roots. Fungi are likely to breed in the roots if they are constantly wet. If your cactus has an extreme infestation, you need to uproot your plant, eliminate or treat the infestation, and repot to a new soil mix and planter. This way, you can control the spread of undesirable nuisance.
Repotting will allow you to choose your desired medium and planter. You can also inspect the roots if it’s healthy, and trim off dead and rotten roots.
When Should I Repot My Cactus? 4 Signs
Cacti should be repotted in case of :
- Rootbound cactus
- Sick plants
- Outgrown pots
- Crowded offsets
Repotting a cactus can be very daunting, especially for beginners. However, if your plant shows signs that it can be dangerous, repotting can save them from dying. These are the signs that your cactus is telling you they need repotting.
Cactus that has been planted in a container for a long time will probably have overgrown roots. A rootbound cactus has its roots circling the top surface of the pot. In case of severe rootbound, they will start coming out from the drainage holes.
When the cactus roots begin to grow out of the drainage holes, it means there is no more room for them to grow inside. Please do not ignore the rootbound cactus because it is the plant’s signal that something wrong is coming.
Just as the plant is getting rootbound, soil particles become less. Unless you are steady with watering and fertilizing (once or twice a year only), dehydration and lack of nutrition are likely.
2- Sick Plant
When the cactus shows signs of discoloration, drooping, wilting, or having unusual spots, inspect it right away as these are signs of an unhealthy plant. Sick plants need attention, and repotting might perhaps be a solution to save them.
Despite being given proper care and nutrition, your cactus can get sick all of a sudden. It can become droopy, discolored, and shriveled. When one or more of these are evident, quickly examine your cactus for possible root rot, pest attack, and other diseases.
However, some signs may not be as evident, and a close inspection might be helpful. You need to uproot the cactus and check the base and roots. If you see unhealthy roots, trim them to promote new growth and replant the cactus on a fresh soil mix.
But if you see rotten, foul-smelling roots, there might be something serious like fungus and pests dwelling underneath, or it can be a sign of overwatering. In this case, you need to treat the plant before repotting.
3- Outgrown Pot
As the cactus expands, the space around its stem gets too tight that sometimes it pushes on the walls of its container. Other cactus grow top-heavy so that their pot cannot support their weight. These are indicators that the plant needs repotting.
Fast-growing globular cacti such as Gymnocalycium and Echinopsis are most likely to outgrow their pots quickly. The pot space gets too tight, restricting further growth of the cactus. Moreover, columnar cacti such as Stenocereus and Mammillaria get top-heavy so that their pots cannot hold them upright.
When experiencing any of these scenarios, it is the right time to repot your prickly friends to achieve their full potential growth.
4- Crowded Offsets
Some cacti species generously produce pups and tend to fill the pots with their offsets. Clumping offsets inhibits growth that sometimes becomes unhealthy for the mother plant. Start removing and propagating the grown offsets to give room for the mother cactus.
Several cacti will grow offshoots or pups around their stems. Often, growers just leave them clumping to the mother plant or wait until they become mature enough for propagation.
When they are big, it’s the best time to separate them from their mother and repot them to a separate container. This way, the mother plant can regain its strength again.
When Is The Best Time To Repot A Cactus?
Repotting can be stressful to cactus. Giving them enough time to recover is essential. It is best to repot a cactus under favorable weather conditions at the end of its dormancy.
The ideal season to repot a cactus is when they show signs of growth after being dormant. Some cacti go dormant in winter and some in summer. Knowing the growing and dormant season of your cactus will help you assess their needs.
Cacti that go dormant in winter will actively grow in spring and summer. So repotting them in early spring before their growth phase can be suitable for them. On the other hand, cacti that enter dormancy in summer grow actively in fall and winter. Likewise, they can be repotted during early fall.
The timing is an essential factor to minimize risk, and the cactus has a great chance of survival. Weather condition is also another vital factor to consider when repotting. Repot when the day is not so hot and humidity is not so high. These conditions will lessen stress on your cactus, and recovery from distress is quick.
Will it be suitable to repot my cactus during the dormancy state?
Your dormant cactus is alive but does not grow actively. DO NOT repot your cactus when it is inactive as it might disturb its growing cycle and may risk harm to your plant. Repotting may damage the roots and cause stress.
Your inactive, dormant cactus cannot heal its damaged roots and cannot handle the stress of repotting, so the chance of survival is low.
Here is a short video for an easy way to repot your cactus.
Frequently Ask Questions On repotting Cactus
In my physical shop and Facebook page, I was asked several times regarding cactus repotting. And here are some of the queries that I frequently received.
Does The Cactus Suffer From repotting?
Changing the condition of your plant is a big deal for them- they get stressed. The most significant factor that makes repotting stressful to cactus is the extreme weather, as the high temperature will affect their roots.
Repotting can damage and break the roots of the plants too. Some fragile roots will inevitably break off when uprooting, even if you are careful. This is why you should not water nor fertilize your newly potted cactus, as it can cause them to rot.
Allow the roots to heal first (7-10 days or more) before introducing water and several months (2-3 months) before feeding with nutrients.
What Is The Size Of The Pot For Repotting?
When choosing a transfer pot for your cactus, opt for the much bigger pot than the last one. Add an extra 1-2 inches size in width, and the depth must be good enough to sustain the growth of the roots.
Avoid using a pot that is way too large and too deep as it may hold too much water that is not favorable for your cactus. A drainage hole is an essential factor when choosing a pot.
Should I Fertilize My Newly Repotted Cactus?
In general, cactus do not need much nutrients. The fresh medium contains relatively low nutrients that can suffice the cactus needs.
Feeding your cactus after repotting is not only unnecessary, it might also burn the cactus’ roots. Hold back until 2-3 months before feeding your precious plant.
What To Do After Repotting?
Once repotting, the cactus should not be watered and exposed to direct sunlight for at least 1-2 weeks. A bright, shaded balcony is suitable for newly transferred cactus as it gradually recovers from the stress of repotting.
Should I Repot My Newly Bought Potted Cactus?
It is always a good idea to uproot, treat, and repot your newly bought cactus. Usually, the potting medium used in garden centers contains too much organic matter and holds too much water longer. This condition might not suit your area and climate, and changing the substrate will make growing more comfortable.
Furthermore, pests and fungi might be present in the existing potting medium of the cacti. It might be best to discard the soil and treat the plant before repotting to avoid pests from spreading to your other collection.
- Repotting a cactus will save them from future problems such as dehydration, pest or fungal infection, root rot, and stunted growth.
- Rootbound cacti or those that have outgrown their containers should be repotted to a larger pot to give more space for their growth.
- The best season for repotting is when the plant is not dormant but actively growing.
- Always remember to avoid exposing your newly potted cactus to direct sunlight and water.
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