How to grow Saguaro (Carnegiea gigantea)

The cactus, there is no other. Well yes, there are thousands but this will be the cactus par excellence. Its size, its uniqueness, its size, how slowly it grows, how perfectly adapted it is to a very specific area of ​​the planet and its appearance in movie westerns have made this cactus a plant legend. Today we tell you what the saguaro is and even if you dare to grow it.


Just as there are genera that encompass hundreds of species, there are specimens so unique, so special that they do not look at all like other plants and deserve to have only one species and one genus. This is the case, for example, of Ginkgo biloba , that living fossil that we have already talked about and today it is another really special specimen: The saguaro or saguaro , a species of the monotypic genus ( Carnegiea ).

The name of the Carnegiea gigantea cactus is relatively modern (less than 20 years old), replacing Cereus giganteus . The common name Saguaro is the common name that has transcended all languages ​​in the same way, coming from Spanish although the root of the word is believed to be from one of the most prosperous pre-Columbian civilizations, the Mayans .

As we can see in the distribution map, the saguaro is endemic to the Sonoran desert in Mexico, spreading towards the United States in the deserts of Arizona and New Mexico.

Saguaro distribution. Extracted from


Although there is a decrease in the population in the desert, this species of cactus continues to be abundant in the reduced space in which it occurs and the decrease observed is not enough to trigger an alert of threat of extinction but of a threatened species. That does not mean that it is not protected, because it is and a lot. The largest specimens can exceed 200 years and it is estimated that this is their life expectancy. Even more.

In Mexico, Carnegiea gigantea is primarily threatened by changes in land use for cattle ranching . In the United States, the saguaro is primarily threatened by urbanization . The saguaro is also threatened by collection in the wild, including for illegal trade . There is a high demand for saguaros because the interior forest portion of this cactus species is commercially very profitable, leading to overexploitation. The species is also threatened by competition from Pennisetum ciliare or better known as Zacate buffel. forage speciesintroduced and classified as very invasive that it colonizes quickly and if there is a fire, it expands at speeds impossible to control, growing after the disaster since it is a pyrophyte species . Native species like the saguaro cannot survive. It is protected in Mexico by the National List of Threatened Species .

They are very slow growing . From seed to 1 meter in height it takes about 30 years. The species grows in well-drained land, on scrub slopes and plains, and amid thorny desert environments.

Detail of the arms of a saguaro. Photo by: Rob Larsen


If you are one of those who like a xerophytic garden with cacti and succulents everywhere, the saguaro could be a specimen to cultivate, but you should know that it is not the most recommended since you will not see it grow too much until at least 2 or more 3 generations.

Also, growing this plant in the garden is unreasonable for several reasons:

  • Its slow growth. 1 meter every 30 years and about 70 years to see a secondary arm grow .
  • It has a life expectancy of more than 150 years . Hopefully your great-great-grandchildren will see it.
  • Their imposing size, in the end they can exceed 15 meters in height and have enormous weights for a garden.

This makes it not a very seen species in garden centers. Yes there are and in fact you can buy them and have them in a pot at home for several years, but the weather sometimes does not accompany them. It must be completely desert . In Spain it could happen in some places of course. I have not particularly seen it. If anyone has seen it, please put it in the comments.

However, in popular culture it is the quintessential cactus, since its structure is very “human” and animation artists have realized that a long time ago.


Planting a saguaro in the garden is a challenge because even in the most privileged regions of our country it will be difficult to achieve optimal growing conditions. We have two big problems with this cactus.

  • It does not support humidity , no matter how minimal.
  • It is not a particularly hardy cactus. Let’s say it is on the delicate side and you only feel comfortable in the area where it is endemic.

However, if you still feel like it, plant it in a well-protected area of ​​the garden , in a very well-drained and sloping ground to promote maximum drainage of rainwater. An incident, direct and abundant sun will be necessary throughout the day for your well-being. Don’t water your cactus at all from September to June.

In summer you can do some biweekly irrigation or even with a longer period of time.

Saguaro bloom. Photo by: Renee Grayson


Saguaro cultivation is however preferable in a well-installed pot in a gallery or greenhouse. The ideal is a large pot (to avoid a later transplant), made of clay, with a hole to let the water drain. We leave a gravel bed at the bottom of the pot to ensure good drainage of the water used for irrigation.

We make a drained substrate by mixing 2/3 of normal substrate, 1/3 of limestone and 1/3 of river sand of medium grain size.

We will provide you direct exposure, south facing . Irrigation will only be necessary during the hottest months. Water abundantly once every 10-15 days and add a little ‘special cactus fertilizer’ once a month.

From September to June, stop watering , as we have mentioned in the cultivation for the garden and fertilize; the lack of water is always preferable to an excess in this type of plants.

As soon as the temperatures exceed the minimum 13 ° C, the plant can be gradually removed in full sunlight where it will spend the rest of spring, summer and part of autumn outdoors, in areas of southern Spain.

Irrigation null or almost null. Rot is assured and you will spoil years of growth if you are not careful in this regard.

The flowers of the saguaros appear in the nights of April and May . Each fruit after flowering can contain up to 2,000 seeds . Its metabolic activity is so slow and it takes so much trouble to bear fruit that it has to ensure its viability as a species by producing such amounts. The spines of a Saguaro less than 2 meters tall grow rapidly, up to a millimeter per day. Then they stagnate and grow more slowly.

Detail of the fruit and the thousands of black seeds. Photo by: Ken Bosma


  • Woodpeckers dig their nests in its trunk, as do finches and swifts.
  • Fruits and flowers attract a multitude of pollinating insects, including several species of bees;
  • Owls inhabit abandoned woodpecker nests, and each year woodpeckers build a new one;
  • At night, the fruit and / or nectarivorous bats come to enjoy the pollen, nectar and fruit of the Saguaro;
  • Certain species of pigeons enjoy the fruits and nectar of this true living desert treasure;
  • The numerous insects and birds attract many predators, such as lynx, wild cats, and diurnal birds of prey.
  • At the feet of the Saguaro, insects such as spiders, scorpions dig their burrows to benefit from the freshness and humidity it provides.
  • The same log can hold up to 3,000 liters of water.
  • Even humans used its structure as beams, as did the early European settlers and native Amerindians.
  • However, all this movement of species can take its toll on the saguaro. In balance is virtue.

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