Armatocereus mataranus: Care and Propagation Guide

Armatocereus mataranus is a tree-like cactus. It belongs to the genus Armatocereus which has many species besides the one we will look into.

It is an extremely rare plant native to South America—more specifically to Ancash and Cajamarca in Peru, and Ecuador.

Armatocereus derives its name from Latin armatus meaning “armed” and cereus meaning “soft”. It belongs to the subfamily Cactoideae.

It is a columnar cactus with cylindrical upright branched stems. There are 5-12 distinct ribs on each stem. They also have a narrower “neck” between the sections of the plant’s length. These sections correspond to the annual growth of a plant.

This cactus grows pretty tall ranging from 6 feet to 20 feet. It also blooms with flowers that are white and near-white in color. They bloom in the late spring to early summer, as well as in the middle of summer. It is quite breathtaking to see this tall plant blossoming.

armatocereus mataranus

The flowers—narrow and tubular–bloom at night. They are characterized by their spiny ovaries and floral tube, and white petals.

Its fruits are large, and spherical or oval. These are spiny as well when it is small. Once it reaches maturity, it loses the spikes. The fruits are red or green in color and contain large black seeds. These seeds are either oval or kidney-shaped.

Armatocereus mataranus has extremely sharp spines and edges, hence you should be very cautious while handling it.

How to Care for Armatocereus mataranus

Caring for Armatocereus mataranus is easier than it would appear. They demand very little attention and do well if given just enough attention. It falls within the 10a and 11 USDA Hardiness Zone.


Armatocereus mataranus needs full sunlight to grow. Plant it in an area with direct sun for at least six to eight hours per day. If direct sunlight is not available, partial sunlight should also work.

It would not do very well under a grow light as it is a plant of the tropical climate and needs full sunlight to thrive.


Despite being a tropical plant, it is still a cactus. Like most cacti, it is drought tolerant. It is ideal for xeriscaping (a process of landscaping with minimal or without irrigation).

You should water it regularly—once a week should suffice. Water it adequately when the soil is completely dry. Avoid overwatering as it might harm the roots. In winter, water your Armatocereus mataranus much lesser than you would in the summers.

Like all cacti, it can store water in its stems and sustain itself over drought-like conditions. But try not to push it to the extent where it needs to depend solely on its stored moisture to survive.

armatocereus mataranus


Plant it in free-draining soil like all cacti. Use sandy soil and extra drainage material such as horticultural grit or perlite in it. This helps not only with drainage but also with space for the roots to grow.

The pH levels of the soil should be around neutral (6.6 to 7.5). Armatocereus mataranus can tolerate mildly acidic (6.1 to 6.5) to mildly alkaline (7.6 to 7.8) pH levels of soil.

We review the best soil for cactus in pots here.


You should use only mild fertilizers and that too only during growing seasons. Do not fertilize the soil while you are planting your Armatocereus mataranus for the first time.

This plant does not demand fertilizing as much as non-cacti plants.


Armatocereus mataranus thrives at temperatures around 35 degrees Fahrenheit. It does pretty well within 30 degrees Fahrenheit to 40 degrees Fahrenheit.

If planted in conditions either drastically hotter or colder than this, the plant will most probably not survive.

This plant does fairly well in the climates of Fredonia and Phoenix in Arizona.

armatocereus mataranus

Pests and Diseases

The plant is sturdy enough to withstand extreme weather, but it is not equipped to deal with overwatering. Overwatering Armatocereus mataranus might lead to its untimely demise. Over-fertilizing is also a big no-no when it comes to this cacti.

If you notice bugs on it, you need to wash it off with a steady jet of water.

Propagating Armatocereus mataranus

You can propagate Armatocereus mataranus using two methods—planting a seed and using cuttings for propagation.

For propagation by planting a seed, you need to find an unblemished fruit. This fruit should be overripe considerably before the seeds are collected from it. Wash the seeds and allow them to dry. The seeds—once dried—can be stored for a long time.

Alternatively, buy seeds from nurseries as the chances of seeing Armatocereus mataranus are very rare.

To grow a plant from a seed, plant it into the soil after the last frost is passed. Water it in intervals and allow the seed to germinate. There you have your baby cacti!

As for propagating through cuttings, there are two kinds of cuttings that can be used:

  • Woody stem cuttings
  • Softwood cuttings

Wash and dry the cutting once collected. Wait for the surface to callous over before you can plant it on a layer of soil.