Month: March 2020

Cacti plants make great indoor and outdoor plants with their bold appearance and brightly colored flowers. These plants are suited to warm and dry conditions and don’t require a lot of attention like other plants. In fact, it is relatively easy to grow cacti plants in your home as long as you provide them with sufficient light, water, and potting soil.

So, what kind of soil is best for cactus? Generally, cacti plants grow well in porous, pebbly, or sandy soil that provides excellent drainage and plenty of aeration. This soil is not special per se, but it is somehow different from the regular soil.  The right spoil must also have plenty of organic matter in it to supply the plant with nutrients as it decomposes. The other function of the organic material is to hold moisture to ensure that the soil doesn’t dry out immediately after watering.

In this post, we look at some of the qualities of the best potting mix and how cacti plants behave in different types of soil. We shall also discuss the dangers of using poorly-draining soil and how you can get the best out of your cactus. Read on to discover everything you need to know about the cactus potting mix.

Before we start, here is a list of our favorite and recommended soil mix (Here)

What Is the Best Potting Mix for Cactus?

Watering is one of the most important and trickiest aspects of growing cacti plants. You need to keep in mind that too much water may cause the roots of your plant to rot while too little water will weaken the plant. Once you master the art of watering your plant properly, you need to ensure the potting mix provides the best environment for your plant to thrive.

The type of potting mix you choose to use will go a long way in determining how much water is retained in the soil. Whether you are growing your plants indoors or outdoors, in the ground or containers, the most critical factor to consider when choosing a potting mix is its ability to drain properly.

Generally, you need to make sure that the soil is porous enough so it can drain well and dry out completely. That is why we stress on going for sand and pebbly soil.

Remember the fact that cacti plants do well with soil that may be considered poor for other houseplants. Good potting mix allows for relatively easier root growth by allowing efficient water exchange and air circulation.

Most commercial potting mix brands are rich in inorganic matter and only a few organic elements. Therefore, you need to check your soil after purchase to ensure it contains sufficient organic elements. Good potting mix must contain between 40-50% organic elements combined with inorganic matter.

The Role of Organic and Inorganic Materials in Cactus Soil

Inorganic materials play a crucial role in cactus soil. They make the soil porous so that it can drain well. They also promote aeration by allowing air to flow through the soil. The most common inorganic materials used in cactus soil are perlite and pumice. The two are often used interchangeably, but they differ in characteristics.

For instance, pumice lasts longer and is more superior compared to perlite. On the other hand, perlite is much more affordable and widely available, making it a much more viable option. Other materials such as gravel and grit are also used in cactus potting mix to limit the amount of water that the soil can hold.

Cactus soil also benefits significantly from organic materials to increase the overall volume of water that the soil can hold and its ability to absorb essential nutrients. Some of the common organic materials used in cactus soil include mulch, coir, and peat.

Defining Quick-Draining Soil

Throughout our discussion so far, we have stressed the importance of using quick-draining soil to grow cacti plants. But what do we mean by “quick-draining?”

Well, the primary objective of any cactus soil should be to allow the plant to absorb water while it is being watered and for a few moments afterward. From there, the soil should dry out as quickly as possible.

By doing so, we are trying to mimic the desert environment where these plants grow. Typically, when it rains in deserts, cactus roots collect water as quickly as possible because the light showers dry up.  This is the same thing you achieve when you use quick-draining soil.

However, there is no strict definition for “quick-draining”, but it is a good rule of thumb for the soil to dry out completely within one to two days after watering.

The easiest way to test if the soil is drying is by sticking your finger at least one inch into the dirt. If it feels dry and warm, then it is drying. However, if it feels much cooler than the surrounding air, it is damp, and that should make you worried.

Quick-Draining Potting Mix and Container Drainage

It is good to note that there is no point in having a quick-draining potting mix if your plant is not in a well-draining pot. You can have the best potting mix, but if the water doesn’t have anywhere to drain, it is still going to stay in the container and cause harm to your plant.

The same thing applies to “drainage layers.” Avoid putting gravel and stones at the bottom of your container, thinking that you are helping with drainage. In fact, these materials block the drainage holes causing the water to stay in the pot.

While your cactus plant can survive in a container with only a few drainage holes, the results may be catastrophic if there is no drainage at all. Therefore, it is always good to go for a pot with plenty of drainage holes to make your plants happy and healthy.

Are Commercial Cactus Potting Soils the Best?

The truth is that there are plenty of commercial potting mixes available, including high-quality custom blends offered by nurseries that specialize in cactus.

Some of these mixes are pretty good, and you don’t need to do anything else after purchase to get them ready for your plants.

However, most of the cactus soils you will find in the gardening section of your local plants’ store may not be the best options for indoor potted cacti plants. Most of them tend to contain a minimum amount of coarse inorganic material which affects drainage.

Keep in mind that your cactus plant will only thrive if you have the right type of soil that drains water efficiently. If you must go for these commercial potting soils, be sure to add in some more pumice or pebbly material to improve the porosity and mineral content of the soil.

Otherwise, the best way to ensure that you have the right type of potting mix is by making one for yourself.  

How Can You Make Good Cactus Soil? A Quick Overview

As mentioned earlier, the best way to ensure you have the right potting mix is by making one yourself.  The process is simple and pretty straightforward. In general, your soil mixture should consist of at least 1/3 part by volume coarse sand or pebbly material if you are using soil as a base.

You should also have approximately ½ part inorganic materials for mixing with the organic materials. Be sure to use different inorganic materials with varying particle sizes for both indoor and outdoor cacti plants.

You can easily test the texture of your soil mixture by carefully wetting some of it and squeezing it with your hand. If the soil mixture clamps together, then you need to add some more inorganic matter. A good mixture should feel coarse and fall apart when you squeeze it.

We shall cover the process of making good cactus soil in detail in another post. So, stay tuned.

Do Cacti Plants Need Soil to Grow? Can They Survive Without Soil?

You may be wondering if your cactus can survive without soil. Well, the truth is that all plants, including cactus, need some growing medium to survive and thrive. You may be seeing cacti arrangements in small terrariums with gravel or sand and wonder if you can grow your plants the same way.

The simple answer is yes. You can grow your plants this way because their hardy nature allows them to survive in such arrangements for a relatively long period. However, with time, the roots of these plants will start to elongate and look for a more suitable medium to grow in.

In most cases, cacti plants planted in the sand, driftwood, or moss will eventually outgrow the container. The moment you notice signs of the plant outgrowing the container, carefully re-pot it in a bigger container with a suitable potting mix.

Otherwise, if you do nothing, it will not thrive and will eventually die. You can think of such arrangements as short-term usage and not long-term strategies.

Summary

Cacti plants are pretty easy to grow and take care of. One of the most important things you need to do to achieve better results is to find the best soil for your plant.  Good cactus soil needs to drain quickly while holding on to the right amount of moisture to nourish the plant when need be.

We hope you have learned a few things about cactus soil that will set your plant up for great success, and here is a list of our favorite and recommended soil mix (Here)

Growing cacti plants can be rewarding. There is a lot to love about these plants, and they will always make your home feel better and more beautiful throughout the year. They have an unusual and diverse range of growth forms and bloom beautifully. 

However, to grow healthy cacti plants successfully, there are three critical things you need to keep in mind: What is the best type of soil for my cactus?  How should I water my plant? How much light should my cacti plants receive to thrive? In this post, we address the question of the soil type.

So, do you need special soil for cactus? The short answer is “Yes.”  Most cacti plants are native to a desert environment. As such, they are accustomed to growing in sandy soil. Therefore, if you bring the plants to a new environment, then you must also provide them with the right soil for them to survive. Specifically, these plants need fast-draining soil.  The soil should also provide plenty of aeration. A good cactus potting soil should comprise of some organic material that retains moisture when the plant is watered but then dries out pretty quickly.

Read on to find out everything you need to know about the right potting mix for your cactus plant. You will be a pro at finding the right type of soil at the end of the guide.

Cactus Plant Soil Requirements

As mentioned in our introduction, good cactus soil should drain water faster. Soil that holds water for too long may cause the roots of your plant to rot, resulting in the death of your plant. Avoid using regular garden soil on your cactus or any other succulent.

It is also critical to ensure that your pot working drain holes to eliminate the possibility of water sitting at the bottom of the container. Feel free to mix your potting soil with some organic material to prevent the soil from drying out quickly.

Cacti roots also love an airy soil. So, you need to make sure your potting mix is well-prepared to provide the roots with sufficient aeration.

Consider re-potting your plants as soon as you see roots starting to exit through the drainage holes at the bottom of your container. Most cacti species will need re-potting at least once every two or three years. Consider re-potting the slower-growing cacti species such as the Saguaro every four or five years.

Re-pot during spring season when the plants are actively growing to avoid causing problems. It is also recommended you water your plants at least two days before you re-pot to ensure the roots and root ball are moist during the re-potting process.

Understanding Cactus Roots and Desert Environments

You are probably familiar with some of the water-preserving mechanisms of cacti plants, such as their highly modified leaves, waxy coatings, and succulent stems. But, do you know that the roots of these plants are also modified to preserve moisture and water?

Understanding how cactus roots adapt to the arid environment will assist you to know why it is so critical to use the right potting soil that will drain water quickly and maintain a free flow of air.

Typically, cactus roots collect and hold water in different ways. One way these roots adapt to the arid environment is by developing a cork-like outer layer that prevents water loss to the soil. Another way is by developing an extensive system of fibrous roots that spread laterally away from the cactus plant allowing it to collect as much water as possible when it rains.

The roots of cacti plants have also adapted to fluctuations in the plant’s water supply. When it rains, the plant develops a new set of roots to collect more water while the existing roots become more effective in absorbing the rainwater. This helps the plant to absorb as much water as possible.

However, when there is no rainfall, the roots dehydrate, and the newly formed roots dry up and break away from the plant. When the roots shrink, they create a layer of air around the plant that prevents moisture collected by the roots from escaping to the soil.

The ability of these plants to rapidly absorb water whenever there is some rainfall is vital to their survival in the desert climate. Keep in mind that the torrential monsoon rains only last a few minutes, and most moisture only soaks up in the upper layer of the ground.

Therefore, the way cactus roots are designed to act swiftly and efficiently to absorb water when it becomes available and then shrink back; they are susceptible to rotting when they are confined in a container and not allowed to dry out properly between watering sessions.

Choosing the Best Cactus Potting Soil

While making or buying a cactus potting mix, you need to make sure the soil is fast draining to prevent root rot issues and oversaturation of your plant cells. However, you need to ensure your potting medium can retain the water you provide for the plant so that the plant can use it before drying out.

Your potting mix must also meet the nutritional needs of cactus plants. Here are some crucial factors to consider while choosing cactus potting soil:

Organic vs. nonorganic

Both organic and nonorganic mixes are ideal for container gardening. The primary difference between the two is that nonorganic mixes need fertilizer to provide essential nutrients to the plant.

However, for long-term use, organic mixes become more sustainable because they are rich in nutrients. The organic materials are usually at various stages of decomposition.

As the organic materials decompose, over time, they continue to fertilize the soil for ongoing use.

Ingredients

The key to choosing the best potting mix is to understand the ingredients. The main elements in most cactus soils are calcined soil or sphagnum peat moss to help absorb water in the soil, vermiculite/perlite to improve soil drainage, and composite organic matter to provide essential nutrients to your plant.

Typically, vermiculite holds more water than perlite and is mostly used in medium to heavy soil mixes. Some potting mix also includes lime to help balance pH when alkaline soil is needed.

Air circulation

Typically, cacti plants require soil that allows air to circulate properly. In most cases, you will want to look for a potting soil that is a bit light and fluffy to help with the air circulation aspect.

Avoid dense or tightly packed soil since it may cause problems in the long run. Soil that gets too dense when it is wet won’t allow cactus roots to grow well. Dense soil also tends to stay wet for too long, encouraging fungal growth and root rot.

Mixed or not mixed?

Some potting soils are already mixed, while others aren’t. Go for mixed soil, especially if you are still a beginner. One of the most significant advantages of pre-mixed soil is that you can use it straight from the package.

You don’t have to spend time preparing it in any way nor add any ingredients to it. This is a convenient option for gardeners who don’t have time to get the soil ready before use.

On the other hand, if you want to mix your potting soil, ensure you understand how to do it correctly. Incorrectly mixed soil can affect plant growth. Make sure the mixture is aerated and well-draining to ensure optimum growth.

Soil pH

You also need to make sure that your cactus potting soil is of the right pH. One of the primary reasons why most people choose to go for commercial soil is that they don’t have to worry about the pH. 

Pre-mixed cactus soil is designed to have a specific pH balance that will help your plants to thrive. The soil should not be too acidic or too alkaline. The best soil pH for succulents and cacti is slightly acidic to neutral. We are looking at values that range between 5.5 and 7.5.

You can test the pH of your soil at home using a digital pH meter. If you want to ensure that your soil is slightly acidic, add some sulfur to it.

If you want to make it more alkaline, on the other hand, you can add some lime. These two ingredients are readily available in garden stores.

The primary objective is to ensure you choose a well-draining mix with the right pH balance.

Be sure to check out this article that discusses how to choose the perfect soil for your cactus plant in detail.

Can I Use Regular Soil for My Cactus?

Well, you can still use regular soil or the African violet soil to grow your cacti plants. However, don’t use them on their own since the results may not be great. These soils hold water for too long, and their organic matter may contain a wide range of fertilizer additives not geared for cacti plants.

Therefore, instead of using regular soil to grow your cactus, consider using it as one of the ingredients when making your oil potting mix. This way, you can be sure to achieve the best results as long as you do everything right.

When using regular soil, add some perlite or vermiculite to improve drainage. You should also add some organic matter, such as composted leaves, bark, or manure. These ingredients will help you get the perfect potting mix for your cactus plants.

What Is the Best Potting Soil for Jungle Cacti?

Throughout this article, we have been discussing the soil requirements for desert cacti. However, there is another type of cactus that we need to mention- the holiday cactus native to Brazilian rainforests. The plant grows in the tropical rainforest that receives sufficient rainfall throughout the year.

For this type of cacti, you still require a well-draining growing medium. But the roots of the holiday cactus don’t have to dry out completely as their desert counterparts do.

Potting soil for holiday cactus should be composed of mainly organic matter. Simply add a significant amount of peat moss to your regular potting mix, and you are good to go.

You can also use coco coir as an alternative to peat moss.

It would help if you kept the soil moist but not soggy at all times. Water when the topsoil feels dry to the touch. Check out this article discussing how often you should water your holiday cactus.

How Often Should I Repot My Cactus Plant?

You should repot your cactus every two to three years. The best time to do it is in the spring before the plant starts its growth spurt.

When repotting, choose a pot that is only one size larger than the old one. Cacti plants don’t like too much space since it encourages them to produce more leaves and stems.

The plant’s roots need to completely fill the pot for the plant to be happy. If you choose a pot that is too big, the roots will have a lot of space, which can encourage root rot.

Go slow while watering a newly repotted cactus plant. Allow the soil to dry out completely between watering. Don’t water again until the pot feels light.

You should also avoid fertilizer for at least six weeks after repotting. This will give the plant time to adjust to its new environment and recover from the stress of being transplanted.

Final Thought

Although growing cacti plants can be challenging, using the right soil makes the work a little bit easier. Good potting soil that is well-drained and nutrient-rich will make your plants thrive and look healthy.

We hope this simple guide has provided you with the essential information you need to know about potting soil for growing cactus.

Cacti are remarkably durable and low maintenance plants. In most cases, they only need sufficient exposure to light, well-drained soil, and careful watering to thrive. Pest issues aren’t common with cactus and are easy to deal with when they arise.  Although these succulents are generally considered hardy, stem drying and browning is a common problem that you may encounter. 

So, why is my cactus turning brown?  Cacti plants can turn brown, yellow, or even purple for different reasons. For instance, if your plant is turning brown from the top, the cause could be sunburn. However, if the browning starts from the bottom towards the top, root rot could be the culprit. Red spider mites and corking could also cause your plant to change color from green to brown.

In this post, we discuss all the possible reasons that may cause your cactus to turn brown and what you can do to save it from the problem.  Read on to find out everything you need to know.

Why Is My Cactus Turning Brown?

As mentioned in our introduction, cacti plants can turn brown for many reasons. In this section, we discuss some of the top causes of this problem.

Root rot

If the base of your cactus plant is turning brown and the stem is soft and yellow, the problem could be root rot. 

Unfortunately, plants with root rot can be quite challenging to save because the rot usually starts inside before working its way out. In most cases, symptoms of root rot will only begin to show when the problem is already advanced. 

The moment you notice signs of root rot, the best thing to do is stop watering the plant and repot it in well-draining soil.

You can also try to save your plant by cutting away all the tissue that is showing signs of rot plus some of the healthy tissue surrounding it to ensure the rot doesn’t spread.

Make sure you use a clean, sharp knife and wipe it with alcohol in between the cuts. Once you are done, be sure to apply sulfur powder on the wounds to help the plant heal. Overwatering and poor drainage soils are the common causes of root rot.

Indoor hazards

Your indoor cacti plants are still at risk from the same pests and diseases as their outdoor counterparts. However, indoor plants may suffer additional problems that are only unique to them.

When your indoor plants start to show signs of browning or drying out, be sure to check that they are not located close to a heat vent.

The blowing hot stream of air from the vent can cause plant tissues to dry out despite the thick layer of waxy that protects the plant. AC vents can also cause similar damage, although it may take longer for the damage to appear.

Typically, if your plant starts browning and feeling brittle on one side, yet it isn’t positioned directly in a window, it is time to consider moving it to another spot.

Sunburn

If your cactus plant is turning brown from the top, the most common and likely cause would be sunburn. This may sound abnormal because most of us tend to think that cacti plants are sun-loving, desert plants.

However, not all cacti species thrive in the hot sun. Some of them require minimal light and partial shade to do well. Cacti plants bought from a plant nursery or store may also suffer sunburn if you do not take time to introduce them slowly to the bright, outdoor light.

In most cases, mild sunburn will appear as whitish discoloration on the sun-facing side of the plant. With time, the whitish spots turn to brown scars which are a symptom of severe sunburn. Cacti plants with severe brown burns have permanent damage, and there is nothing you can do about it.

But, if your plant has whitish spots, you can save it by moving it to a shady area. As long as you provide shade on the hottest days of the year, it will fully recover. It will also help if you take some time to learn about your plant’s lighting requirements so that you can provide the best conditions possible.

Keep in mind that cactus species that aren’t used to being in direct sunlight must be acclimatized by exposing them to full sunlight for a short period each day.

Start increasing the exposure progressively over several weeks.  It won’t be long before your plants fully acclimatize to the outdoor light conditions. 

It is also good to mention that some cacti plants should never be exposed to full sunlight all day.

Scales

Scales refer to small insects that usually appear as brown spots on cacti plants because of their hard brown shell coverings. These insects feed on plant juices that weaken the cactus plant making it look yellow or brown.

If this is the case with your plant, consider spraying it with a stream of water to get rid of the scales or wash it with a relatively weak solution of detergent. You can use your preferred brand of insecticide for large infestations.

The other way of killing scales is by using cotton swabs soaked in horticultural oil on each side. This forms an oil layer on top of the scales cutting off the oxygen supply to the insects.

With time, the insects suffocate to death.

Frost damage

Just like sunburns, frost damage can also cause cacti plants to turn brown in affected areas. The damage is quite similar, and the only way to differentiate between sunburn damage and frost damage is by checking the temperature.

When tissues of a cactus plant are subjected to freezing temperatures, the cells rapture. Although you may fail to notice the damage right away, the plant will try to self-heal by creating calluses over the damaged tissues.

This is the same type of self-healing mechanism that occurs after a hail storm as well although the brittle spots on the plant are usually patchy.

Frost damage can still happen on indoor plants that come in direct contact with the window glass.

Mites

If your plant is turning brown from the top where new growth is appearing, it could be a sign of mite infestation. 

Red spider mites are tiny insects that suck juices from your plant at the more tender parts. These insects are so small such that it might be relatively easier to look for their webs other than the insects themselves.

Symptoms of mite infestation include rusty brown spots that appear at the top of the plant and the presence of mite webs.

If left untreated, these pests can kill your plant by feeding on the entire outer layer of tissue. Indoor cacti are the most susceptible to red spider mites.

Sometimes, the plants come from the nursery when they are already infested with these mites. To get rid of bugs, consider watering your plant from overhead with a relatively strong stream of water.

Root lice are another common type of mite that may infest your cactus. Root lice can jump from pot to pot for plants grown in greenhouses, making it difficult to control.

The best way to deal with root lice is by separating your new plants from the other plants for a few weeks. You should also avoid soil sharing and recycling to control root lice.

Corking

The sudden appearance of firm barklike and brown tissue a few inches above the soil of an otherwise healthy cactus plant could be a sign of corking.

Fortunately, this is part of the natural aging process of cacti plants that shouldn’t worry you so much.

In most cases, corking starts from the base of the plant and moves upwards progressively. If your plant is browning due to corking, there is nothing you can do about it because it is a natural process.

Just focus on taking good care of it to slow down the aging process.

How Can You Prevent Your Cactus from Browning?

Are you wondering if you can protect your cactus from turning brown? The good news is that there are lots of things you can do to avoid this problem.

The best way to keep your plant from turning brown is to make sure it is growing in a conducive environment. Also, make sure you quarantine new plants and scrutinize them for pests and diseases before you expose them to your other plants.

To avoid browning as a result of root rot, provide your plant with loose and well-drained soil.  Expose it to sufficient light and avoid overwatering. More than 90% of root rot cases occur as a result of overwatering.

In fact, cacti plants recommend underwatering instead of overwatering.  Always remember the fact that overwatering cacti plants is much more dangerous than underwatering.

The Bottom Line

Browning is a relatively common problem that many cacti gardeners have to deal with. Fortunately, this is not a death sentence for your plants. When you notice brown spots start to form on your plant, take time to identify the problem and deal with it accordingly.

Do not panic or try to solve the issue without understanding its cause. If you cannot identify the cause on your own, don’t be afraid to call in a plant expert to help you solve the problem. Keep in mind that growing healthy cacti plants require good care!