What Does A Cactus Root Look Like

I’ve cultivated a variety of cacti species, and I can attest that each one has a distinct personality both on the outside and in terms of their roots.

These roots often have large, lateral systems that extend away from the plant.

These roots are often shallow in the desert, however they are deeper in locations with more precipitation and competition as they struggle to survive and find the essential water and nutrients.

Others, like barrel cactus, have more compact, shallower root systems that enable them to catch dew water that falls off the cacti.

The cacti has evolved to exist on very little water by absorbing as much of it through its root system, even though this may not seem like enough water to support a plant.

Each of these various kind of roots helps cactus live in a variety of environments.

Are the roots of cacti deep or shallow?


Cacti have shallow roots, with the average depths for their diverse native Sonoran Desert species ranging from 7 to 11 cm and 15 cm for cultivated opuntioids; the cultivated vine cactus Hylocereus undatus has even shallower roots.

Although this shallowness makes it easier to absorb water after light rains, it also exposes the roots to high temperatures near the soil surface.

Extreme temperatures reduced the uptake of the essential stain neutral red into root cortical cells, with 50% inhibition (LT50) occurring for Nopalea cochenillifera, Opuntia ficus-indica, and O. robusta at an average of 7C for low temperatures and 57C for high temperatures, and for H. undatus growing at a moderate day/night air temperature of 25/20C, at 2C and 52C, respectively. The opuntioid LT50s showed seasonal adaptation to changing ambient temperatures, declining 1.2C as day/night air temps were lowered by 20C and rising 4.4C as they were raised by 20C.

In order to measure root growth, respiration, and layers with deadly temperatures, an equation is proposed to estimate soil temperature as a function of soil depth and time.

In this regard, the ability of most cacti to be cultivated today and in the future should not be constrained by the roots’ sensitivity to low temperatures.

Although fewer cacti roots may be found in the topmost soil levels as a result of rising air and soil temperatures brought on by global climate change, other (non-CAM) perennials should experience far larger restrictions.

What kind of roots do cacti have?

Cacti also contain lateral roots, which branch out frequently as they grow, in addition to taproots. Some cacti rely on this network of roots to keep them in place while also gathering food and water because they lack taproots. Saguaros can swiftly absorb rainwater from even small showers because they have an enormous number of tiny roots in the top 3 inches of soil. A young saguaro that was just 6 inches tall was discovered to have a root system that covered a 6 1/2-foot area but went no deeper than around 3 inches.

The Stem

In contrast to other plants, cactus stems are multipurpose. In addition to supporting the entire plant, it serves as:

  • a water storage facility where plant water can be kept in case of drought.
  • using sunlight to provide nourishment for the plant

This suggests that a healthy cactus should have a sturdy, upright stem. The stem will typically be green. The stem’s green hue should be uniform and free of any blemishes or rough spots.

Photosynthesis, which keeps the plant alive, is made possible by a healthy stem. Cacti use a technique known as CAM photosynthesis, which allows them to absorb carbon dioxide at night when temperatures are low and evaporation is minimal. Later, during the day, this carbon dioxide would be used to create oxygen and sugar.


While some cacti contain only a few tiny spiky leaves, others make up for this with pads or spikes. The colorful pads of a healthy cactus show no symptoms of leaning over or wilting. Depending on the variety of cacti, the pads would get more numerous throughout time, giving the pant a chance to develop into new plants. Typically, insects or herbivores seeking to feed on the pads may assault them. Dings and discolouration of the outer skin result from this. However, keep in mind that yellowing in the stem or leaves as the cactus ages may be seen; this is natural.


Flowering cacti are almost universal. The flowers often bloom for a brief period of time and only during certain seasons. Every season, a healthy cactus produces vibrantly colored blossoms. A flower on a cactus could have five to fifteen petals, commonly merged with the sepals, depending on the species. Additionally, it has several stamens surrounding a stigma with multiple loves.

A sick cactus could skip several flowering periods or not flower at all. This could be brought on by a shortage of water or nutrients. Notably, a cactus plant’s age can influence whether or not it blooms. Others cacti may stop flowering after a particular age, while some may take years to mature and produce flowers. But it’s crucial to make sure your cactus receive the recommended amount of water and sunlight.


Depending on the species of your cactus, an abundance of fruits and seeds usually follow the flowering season. After flowering, a healthy cactus would yield luscious fruits and robust, full-sized seeds. Juicy edible fruits are produced by some edible cactus species, including the prickly pear, barrel, and dragon cactus. A cactus in good health will consistently produce fruits and seeds for the majority of its life.


A cactus plant in good condition has many upright spines covering its entire surface. These are designed to aid in defending the plant from outside herbivore attacks. By protecting the cactus from cold or dry weather, the spines maintain its health. A plant in difficulties and at risk of perishing from outside threats will have weak or broken spines.

Skin surface

The surface of a healthy cactus plant is wet, shiny, and ribbed. With the ribbed surface, the plant may expand without worrying about bursting as it takes in more water for its reservoir. In times of drought, a healthy cactus also has a waxy surface that aids in lowering evaporation. The plant’s waxy covering also serves to keep pests from consuming the soft and wet inside of the plant.


A cactus with unhealthy roots could end in calamity. The plant is frequently attacked by root rot, which can be fatal if immediate care is not given. Therefore, it’s crucial to comprehend the traits of strong roots.

Cactus roots cannot be accurately assessed without the plant being uprooted. You could do this when repotting. Typically, healthy roots are white or gray in color. They are wet, and some of them may have colorful hairs surrounding them. Brownish or dark colored roots may indicate that the plant as a whole is not in good health, not just the roots.


Cactus health depends on the soil being in a perfect state for the plant to efficiently absorb nutrients. A healthy cactus will thrive in light, permeable soil. This type of soil ensures the ideal drainage to prevent soggy circumstances that could cause root rot and eventual death. You can choose to produce your own soil mix at home for planting, or you can buy the commercial soil mix found in most arborist supply stores. Here are some of our top picks.

Potting container

A healthy cactus is a given if it is planted in a good-sized pot with drainage holes. It should be a sign of a healthy cactus if the container can still retain the plant comfortably and there are no signs of the roots growing through the drainage holes.

For best results, think about repotting your cactus annually or whenever overcrowding of the roots is noticed. A bigger container provides the plant more room to expand and become more vivid.

How can I tell whether my cactus has roots?

Four weeks after potting the cactus cutting, check for roots. Put on gardening gloves or take hold of the cutting’s base with tongs. Lift it lightly to check for movement resistance, which indicates the presence of roots.

How deep of a pot should a cactus have?

The pot or container you choose for your cactus is crucial and might have an impact on the health of your plant. We will discuss many best and worst cacti pots and containers in this article. We’ll also discuss the advantages and disadvantages of various pots and the significance of size and shape.

Cacti and their growth are significantly influenced by the type of container, its form, and size. While some containers are ideal or excellent, others are completely inappropriate.

Importance of cacti pot/container shape

Before we discuss container materials, let’s discuss another crucial aspect. Take care of the container’s form while buying one for your cactus. When purchasing a planter for your cactus, some qualities to consider include the following:

  • The size of the container should be similar to that of the cactus. This is so that, if planted in a large container, cacti’s roots, which are frequently not very long, will remain in the middle of the container.
  • Cacti grow well in cylinder, short, and square pots. Avoid selecting containers that are overly deep, tall, or small.
  • All of the dirt in the container should be “used” by your cactus. Therefore, there shouldn’t be an excessive amount of dirt that the cactus roots can’t penetrate. Only leave enough room around the plant for growth and drainage in the bottom.

Size of pots for your cacti

As we’ve already established, your cactus, and more specifically its roots, should practically be the same size as the pot. The best plan is to take your cactus outside and examine its roots before selecting a pot or container. Remove a cactus from its current container, examine the roots, and measure them.

Your cactus needs a wide container if its roots are short but growing to the sides, and a deeper container if its roots are long and spreading outward. Additionally, you’ll need to give room for drainage, so a pot should be just a little bit deeper than the roots.

To make your cactus comfortable in the pot, while picking a pot, add around 1-2 inches in width (to your plant’s full width). Depending on the type of cactus you choose, the depth of the container should be between 4 and 7 inches. Cylindrical cacti, for example, have lengthy roots, whereas other varieties have shorter roots (such as ball cacti).

Ceramic terracotta or glazed ceramic pots/containers for cacti

Among the advantages of ceramic planters are:

  • Pots made of ceramic are sturdy and weighty.
  • Ceramic pots come in a variety of styles and colors, many of which are glazed, making them a great option for ornamental settings.
  • Ceramic pots’ porous nature prevents water logging or accumulation (provided you have potted your plants in the right soil mix).
  • They are lovely and stunning in any environment.
  • They are appropriate for the colder months when it is not as heated outside.

Several drawbacks

  • Terracotta planters in particular are porous and minimize water buildup, however this can be detrimental to young seedlings and plants. This indicates that the soil will dry up more quickly, especially if you leave your cactus outside and during hot weather. You can forget about it, but frequent watering can also cause the pH of the soil to rise. In the section on selecting soil for cactus, we talked about how the pH of the soil should be acidic. However, larger plants thrive in ceramic containers.
  • To avoid having to drill the drainage holes yourself, make sure the ceramic pots include them. Drainage holes are necessary, but they might not be present in all ceramic pots.
  • Cactus roots may not penetrate the soil completely and instead focus on the sides. This occurs as a result of the ceramic container’s water evaporating quite quickly and leaving behind mineral residue on the sides. The roots of cacti lean to the sides in an effort to reach these minerals, but they can only burn themselves because the sides of the planters heat up.
  • Ceramic pots are more likely to develop mold.
  • Ceramic utensils may crack (especially with children or pets).

Make sure to choose the appropriate size and shape when selecting a ceramic planter. This set of three ceramic planters for small plants serves as an illustration of a ceramic pot or planter for your cacti.

Plastic pots/planters/containers for cacti

Plastic planters are another kind of container that is excellent for growing cacti in.

benefits of using plastic containers to cultivate cacti:

  • Plastic containers are portable and lightweight, making them simple to transport.
  • Less watering will be needed to maintain soil in a plastic container because it will dry out more gradually. In comparison to ceramic pots, this means fewer watering sessions.
  • Cacti do well in plastic pots since they don’t overheat easily and can retain heat even after the sun has set. Because most cacti don’t enjoy quick temperature drops, this is a useful feature.
  • The low cost of plastic pots offers an additional benefit.
  • To avoid waterlogging, most plastic containers feature numerous drainage holes. Additional holes can be drilled if necessary.
  • The roots of cactus do well in plastic containers because they spread out uniformly across the soil. This is because roots won’t lean to the sides of a plastic container since water won’t evaporate through the sides. Additionally, the acidity of the soil will last longer.
  • The likelihood of mold formation is decreased.
  • Both little and large adult cacti do well in plastic containers.
  • If you bang on them from a table or windowsill, they won’t break.

Hanging containers for cacti

For your cacti, you can also choose hanging basket pots. Smaller or larger trailing cactus can grow in hanging pots. Additionally, you can use them to indoor or outdoor adorn your home. Make sure your hanging pot has drainage holes and perhaps a saucer to catch any water that may drip from it as many hanging pots lack these features. These particular plastic pots allow you to drill your own holes in the bottom.

Bad containers for growing cacti

Let’s start by stating that growing cactus in glass pots is not recommended. A cactus terrarium is often made in a glass container. This is not the same as letting a cactus develop for several years. Cacti do not appreciate humidity or waterlogging, thus terrariums are not the best environment for them.

Glass cactus containers have several advantages.

  • For a special occasion, you may assemble a lovely terrarium with cacti and take the plants out right away (maximum of 2-3 weeks). If you’re making cacti terrariums, only use open glass containers. Plant cacti together only if their requirements are comparable. For making a cactus terrarium, you can add decorations like colored sand, shells, and figurines. Utilizing small, recently-planted cacti is the best option.

Cons of using glass cactus containers:

  • Glass containers are very unlikely to have drainage holes, which can lead to water logging and a buildup of moisture. This will result in root rot, which will ultimately kill your plant. You must exercise caution and give your plant some water each day, but doing so runs the risk of preventing water from penetrating the soil completely and reaching the roots.
  • Even an open terrarium is susceptible to fogging up and having an elevated humidity level within. Cacti require sufficient airflow and detest humidity.
  • Your cactus won’t be able to absorb water from the rocks in the bottom layer of soil if the dirt is layered. Roots cannot obtain water from rocks, and neither can rocks absorb it.
  • A glass container’s sides will quickly heat up and may burn your cactus and its roots. Your cactus may actually be cooked to death if you put it in a terrarium out in the sun.