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Pachycereus Marginatus – Cactus Care Made Easy

Pachycereus Marginatus – Cactus Care Made Easy

Perhaps one of the most common plants you may have come across in this lifetime from the cacti family is Pachycereus marginatus or commonly known as Mexican Fence Post cactus according to Arizona University.

Plant care for Pachycereus marginatus involves cactus soil mixture, direct sunlight in spring and summer, and watering once the soil is completely dry. In the wintertime, these plants go through a dormancy period and best thrive from neglect. The best temperature range for this cactus lies between 25 degrees Fahrenheit (-3.9 degrees Celsius) to 50 degrees Fahrenheit (10 degrees Celsius)

Lesser-known for its name, the appearance of this plant has been widely seen across cactus plant owners, especially in Central Mexico where this plant is most prevalent.

It is with certainty that once you see this plant, a bell will ring in your head and a sense of familiarity is instilled.

Pachycereus marginatus is a columnar growing cactus that can go as staggeringly tall as 15 meters high in nature and about four meters tall when kept as a houseplant.

In its natural habitat, Pachycereus marginatus cacti plants are raised in a desert environment and are very self-sustainable.

If you are looking for a plant that is easy to care for as you go about living your life, then Pachycereus marginatus would be your plant.

They give off a healthy green glow, strong and independent with a personality as sharp as you could imagine.

Get it? Puns aside, scroll through this article that delves into points of how to best care for this cacti species. Much of the magic you see in the growth of this plant stems from the beauty of nature taking its course.



Pachycereus marginatus Plant Care Guide



Interestingly enough, Pachycerus marginatus plants in nature can grow with just the rocks surrounding them.

They have a mutually beneficial relationship between these rocks and the bacteria in their roots. The roots soak up the nutrients from the rocks and mesh them with the plant.

Of course, when you have a Pachycereus marginatus at home, you would need to have proper soil. You can get an already prepared cactus soil mixture to use.

Ensure that it is well-drained, thus when you water them, the soil will be able to sufficiently drain the water completely instead of keeping the plant sitting in moist soil.

Moist soil would be detrimental to the survival of this cacti species.



In the warm months of spring and summer, full and direct sunlight should be given to pachycereus marginatus.

These cactus plants love a whole lot of vitamin D from the sun. Being desert plants themselves, they can withstand heat and parched conditions.

Therefore, you shouldn’t have to worry too much if you place them outdoors during the peak hours of sunshine.

If you place pachycereus marginatus indoors at home, place them in a brightly lit room where they are exposed to as much natural light as possible.

In the wintertime, you would want to promote the plant’s dormancy. As in, give as little attention to them, not that they crave attention, to begin with, and just let them be alone.



Pachycereus marginatus is a plant that can live independently without being taken care of most times, if at all.

Because they thrive in desert-like conditions, you would want to try your best to mimic the same scenario when at home.

Like most plants, over-watering them is more harmful then under-watering them. In the summer growing months, you can water your pachycereus marginatus once the soil has completely dried from its last watering.

This could be once every week or once every other week, using your discretion. In the winter months, no watering is required.

You want the cactus to have a cozy hibernation in the cooler months, therefore, keeping them dry is of utmost importance.



When trying to find just the right temperature for Pachycereus marginatus, going for something similar to this species natural habitat would be ideal.

Obviously, none of us humans would thrive well in desert climates. Thus at home, room temperature should be fine as long as the environment can be dry enough for this plant to healthily grow.

If you live in moist conditions, consider investing in a dehumidifier as a recommendation.

Pachycereus marginatus can live in temperatures as low as 25 degrees Fahrenheit (-3.9 degrees Celsius) to 50 degrees Fahrenheit (10 degrees Celsius).

As a houseplant owner for this kind of cactus, try to find that middle ground where plants and their owners can coexist.



Pachycereus marginatus can withstand strong heat, however, the same cannot be said about humidity.

Any ounce of humidity and moisture can cause harm to this cactus whereby their roots and stems would rot and they could then potentially be subject to fungal diseases.

The amount of watering you give goes hand in hand with humidity. When you water this cactus plant, most of the water is already stored in the bulky tubercles that would allow them to sustain in dry and cold conditions.

Therefore, you do not need to worry about watering them too much as there is low to zero tolerance of humidity.

If you want a quantifiable reference point in terms of humidity, try to stick to moisture levels of about 30%. This would be the safest choice. These plants are tough to endure periods of parched conditions.



Fertilizing is not exactly a necessary step for pachycereus marginatus, though using some to help with its growth would certainly be beneficial.

Obtaining a store-bought fertilizer for cacti plants would suffice. In the warm growing months, you can fertilize roughly once a month at equal proportions of nitrogen, phosphorus, and potassium.

Just like the steps you would take for watering, refrain from fertilizing pachycereus marginatus in the winter time. This is the time when you want to encourage hibernation, or dormancy, of this plant.

For your general knowledge, fertilizers contain nutrients like nitrogen, phosphorus and potassium.

When purchasing fertilizers, you may notice a three digit number ‘#-#-#.’ This shows how many pounds of nitrogen, phosphorus and potassium there are in the mix, respectively.



To propagate pachycereus marginatus, you can do so using two methods. One method is to use seeds to initiate new growth. Another method is to use stem cuttings to carry out the growth of a new cactus.

Both methods will be discussed further in detail in the propagation section below.



Pachycereus marginatus grows quite slow mannered similar to some of their cacti counterparts.

They make very easy plants to keep in your home as they essentially require minimal to no assistance, hence, making them low maintenance.

Though it is said that if you grow your pachycereus marginatus outdoors, it would be slightly faster. It could potentially grow 1 meter high each year by giving it the proper care.

Generally-speaking, they can grow as tall as four meters, which is roughly 12 feet tall. The stems of the plant have 5 to 7 ribs that are each about 4 inches in diameter.

They have areoles that are spaced about 1 centimeter apart. As for the spines that grow on them, they can be up to 1 centimeter long.

The spines are typically longer in developing plants and shorter on the matured ones.



To find the right pot for a pachycereus marginatus plant, find one that is sturdy enough to host a tall growing, columnar plant.

The pot ideally would have holes at the bottom to aid in properly draining water from the soil and providing sufficient air circulation.

Material-wise, aim for a clay pot as it should be porous enough to release moisture and give off great aeration.


Pachycereus Marginatus Care

Pachycereus Marginatus Care


Propagating Pachycereus marginatus step-by-step

When propagating a Pachycereus marginatus, do so during the warm, growing season. You can propagate using seeds or by cutting a stem off from the mature part of the plant.

To propagate using seeds, you should experience an easy to moderate germination and growth process.

Have a clean pot with fresh soil mixture. Add in a bit of cactus fertilizer to help initiate growth.

Spread the seeds in the mix and water. Follow the proper steps in this plant care guide and you should be able to see a beautiful Pachycereus marginatus sprout.

If you choose to propagate by cutting, make the cut at the joint where the segment is attached to the main parent plant.

Then, place the cut part in a dry, shady spot to let it callous for about two weeks. You want this to be completely dry before you plant it into the ground or your freshly prepared pot.

You can plant this new cactus in full sun, but during the first summer, do provide some shade to help kick start a healthy growth.

For example, you can use a shade cloth to cover the top of the plant.


Common Problems with Pachycereus Marginatus

There may be times when pachycereus marginatus become susceptible to fungal disease. This occurs when the soil sits in moisture for quite some time.

The cactus would then suffer from irritable consequences. Therefore, take the necessary precautions outlined in this guide.

Also, ensure you provide a good healthy dose of light from the sun. For a cacti species, pachycereus marginatus is extremely self-sufficient and durable on its own without being touched or constantly monitored.

As a result, there aren’t too many common problems they face.


Tips to Keep Pachycereus Marginatus Problem-free

To keep your Pachycereus marginatus problem-free, following the steps outlined in this plant care guide would be a great reference in combination with using your own knowledge as a plant owner.

Give this cactus a lot of love from the sun, monitor soil condition and water levels to ensure proper drainage, and adjust temperatures and humidity levels when necessary, especially during changing seasons.


Frequently Asked Questions About Pachycereus Marginatus


What do I do if I over-watered my pachycereus marginatus?

If you over-watered your pachycereus marginatus, fret not. Let your cactus sit untouched to see if the water will completely drain from the soil mix.

After several days or so, if the soil cannot dry completely, then consider repotting the plant. To repot, you can check out the third frequently asked question below.


Do I need to prune pachycereus marginatus?

Pachycereus marginatus do have pinkish to green flowers that grow in the areoles of the plant. You may be lucky enough to find two flowers per areole that can blossom to be three to four centimeters long.

However, don’t expect that these flowers will last long. They blossom for a short period of time and begin to wilt. Therefore, you don’t need to prune a pachycereus marginatus plant.

How do you repot pachycereus marginatus?

Being such low-maintenance cacti plants that can go untouched and still be able to grow properly, repotting isn’t always required.

However, in the case where you are growing pachycereus marginatus in a pot or container, you may want to repot when you believe that the plant it outgrowing its pot, or if the soil is not draining the water.

To repot, you would follow essentially the same steps as potting the cactus for the first time. Have a clean pot or container, add in some fresh soil mixture and some fertilizer to kickstart and maintain its growth before placing your pachycereus marginatus inside.


Why are pachycereus marginatus used as fences?

Pachycereus marginatus are used as fences because they grow tall, tough and bulky and have long spines that can be a protectant for your home. They are basically Mother Nature’s safety net for the home. Therefore, you don’t need to go out of your way to build an actual fence.



Pachycereus marginatus make individualistic plants that can support themselves for the majority of their livelihood.

Even for the most busy, non-homebody houseplant owner to exist, you can still be able to provide this cacti species a means to live a prosperous lifestyle.

They are tall and slim yet, they can also defend themselves, you included, when faced with danger.

When looking for your next hassle-free plant, look no further than a pachycereus marginatus. They will offer your home a vibrant green and literally take your breath away.

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