Stenocereus marginatus (Mexican Fence Post Cactus) is native to Central Mexico. This cactus (also known as Lemaireocereus marginatus) features a large cylindrical stem that is dark green in color and has multiple ribs across the surface. The ribs also have white or brown edges, sometimes with spines.
Due to the height of these cacti, they (or sometimes just their cuttings) are often used to build boundaries or fences. These cacti are not generally as sharp as other species.
29 Types of Stenocereus With Pictures
How to Care for the Stenocereus marginatus
The Stenocereus marginatus requires several conditions to be met so that it can grow well. Let’s take a look at what these are.
The Stenocereus marginatus needs plenty of sunlight to grow well. You can find this kind of constant direct light if you grow your cactus outdoors in a way that it receives sunlight for over six hours. At the same time, a certain amount of shade would also suit it.
If you are planning to grow the cactus indoors, you can do so in a pot. However, make sure you place the pot in an area that receives a good amount of sunlight, such as a balcony or a window.
You can also make use of artificial light meant for this purpose if you cannot access sunlight.
The Stenocereus marginatus as a cactus that can survive in arid regions does not need large amounts of water to grow. A good frequency to maintain would be to water this cactus once every 7-10 days in spring and summer.
While doing this, it is important to ensure that the soil has dried off completely before you water it. You can check this by putting a finger or stick in the soil to check if it is still moist.
Make sure you avoid watering the cactus too much as this could lead to root rot, making the cactus shrivel and die.
During the winter months, this cactus becomes dormant and requires watering very rarely or not at all.
You can opt for a potting mix that specifically caters to cacti as long as it drains well and quickly. You can then add sand or perlite to this mix to facilitate better drainage. This will provide a good environment for the roots to grow healthily.
Do make sure that the soil you choose has thin or fine particles that allow the water to clear out as waterlogging or retention will cause the roots to rot.
You can easily find these growing materials in local nurseries.
The Stenocereus marginatus grows well in the heat, which is why you can easily grow it outdoors if you live in warm climates (USDA zones 9-11) or during the summers. Even if you are growing it indoors, your cactus will grow well as long as it has a temperature of 65℉-85℉.
In the winter, this cactus can withstand the cold, but if temperatures go below 25℉, you might need to shift the cactus indoors. This is because extremely cold temperatures can cause the cactus to freeze, after which it might not recover.
Generally, you should avoid letting your cactus face extreme fluctuations in temperature to allow it to grow to its capacity.
During the growing months of this cactus, you should fertilize it once every one or two months to allow it to make good use of the nutrients. It is not necessary to fertilize the cactus during the winter months due to its dormancy period.
There are several fertilizers that you can use for this cactus. Some of them are made specifically for cacti that would make a good choice to opt for. You should add a bit of water to dilute the fertilizer so that it does not prove to be too strong for your cactus.
If you want to grow your Stenocereus marginatus in a pot (whether indoors or outdoors), you must ensure that it is porous enough with drainage holes so that it can allow the water to drain out easily to prevent waterlogging.
You will also need to keep repotting this cactus either annually or once every two years since it tends to grow at a rapid speed and needs bigger containers to grow healthily.
While potting or repotting, make sure that you use clay or plastic containers. Fill the new pot with the soil mix and then carefully clean up the roots before placing the cactus in it.
Pests and Diseases
Your cactus will be at risk of several pests and diseases if you do not maintain optimal growing conditions.
For example, pests such as mites, bugs and whiteflies might affect your cactus, leading to colored spots, nests or mold. You can get rid of these using suitable insecticides or by momentarily increasing the humidity.
Diseases like root or stem rot and the growth of fungus could occur as well. You can prevent these diseases by avoiding over-watering and waterlogging along with providing enough light and air to your cactus.
How to Propagate Stenocereus marginatus
You can propagate the Stenocereus marginatus by cutting off a stem from a grown cactus. Go through the following steps to figure out the process:
- Cut the stem using a sharp knife at an angle to make it easier for the main plant to grow back the stem.
- Keep this step aside for a while so that it can dry up and grow a callus.
- In a pot that contains the soil mix, place the stem cutting and cover up parts around it with the soil in a way that it rests evenly.
- Water this mix lightly and place the pot in your desired location, ensuring that it gets enough light and heat.
- Allow it time and space to grow to its capacity. Make sure you water it once a week and repot it whenever necessary.
You can also use seeds to grow this cactus by covering the seeds with the soil mix in the pot and then following the same steps as above. If you need to store the seeds before propagation, make sure you do so in a cool and dry place.