Guide to Saguaro Cactus: How to Grow & Care for “Carnegiea Gigantea”

Read our complete guide to the Saguaro Cactus for everything you will ever need to know! Tips for growing & caring for “Carnegiea Gigantea” Cactii
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Carnegiea Gigantea, usually known as Saguaro, is a species of tree-like cacti in the Cactaceae family and a magnificent sight to see. These cacti are native to the Sonoran Desert in Arizona, but they can also grow in the Mexican state of Sonora and other regions in California such as the Imperial County and the Whipple Mountains.

Saguaro cactus was first described in 1848 by William H. Emory during his studies of the United States-Mexican border. Starting from this description, the German-American botanist and cactus expert George Engelmann formally named the species in 1859. It is the only specimen in the monotypic Carnegiea genus.

The Saguaro is the largest and most exotic cactus in the United States. These friendly giants have many different uses. Their woody ribs can be used to build furniture, fences, and roofs and Native Americans have used them as water and food containers for centuries.

About Saguaro Cactus

  • The Saguaro National Park was designed in 1994 to shelter this species and its natural habitat. Nowadays, Saguaro cacti are completely protected from extinction.
  • The generic “Carnegiea” name was given in honor of the philanthropist and businessman Andrew Carnegie, while the specific epithet “Gigantea” obviously refers to this species’ formidable size.
  • Some Saguaro cacti can grow in rare and unusual shapes called “cristate” or “crested” saguaro. This formation appears as an abnormal growth at the top of the cactus or the arm.
  • Saguaro cacti are extremely important elements of the desert ecology, both as nests and food for birds. They provide large amounts of pollen, fruit, and nectar.
  • The flowers of this species are considered the state wildflowers of Arizona.
  • They enjoy basking in direct sunlight, but not for extended periods of time. Place your Saguaro cactus in a bright spot that provides it with both direct and indirect light.
  • Although they are drought-tolerant, it is better to water them moderately, as this will ensure optimal growth and blooming. Water them less often in autumn and winter.
  • Plant your Saguaro cactus in well-draining potting soil and feed it with a balanced cactus or liquid fertilizer during their growing season.
  • Saguaro cacti pair well with other cacti species, agaves, aloes, and yuccas. You can plant them together, as they do not demand extra individual care.
  • Keep these cacti away from curious pets and children, as they can be very stingy.
Saguaro Cactii in the Wild
Saguaro Cactii in the Wild

Saguaro Cactus Features: An Overview

  • Saguaro cacti grow at lower altitudes due to their intolerance of cold temperatures or extended periods of frost.
  • These cacti have a pretty slow growing pace, but they can live between 150 and 200 years. They are the largest cacti that grow on the territory of the United States.
  • In the wild, Saguaro cacti can reach up to 52.5 feet (16 m) in height and up to 30 inches (75 cm) in diameter. The tallest cacti of this species measured 78 feet (23.8 m).
  • Generally, Carnegiea Gigantea cacti grow lateral stems after about 75 years. Some specimens do not grow arms at all during their lifetime.
  • The spines on a Saguaro cactus can be very sharp, growing up to 0.03 inches (1 mm) every day. They usually grow in areoles that start from the apex of the cactus. The spines stop growing after their first growing season and can reach up to 2.8 inches (7 cm) long.
  • They exhibit creamy-white and waxy bloomings from April to June that can grow between 3.4 and 4.9 inches (8.6-12.4 cm) long.
  • Their flowers remain discovered for less than a day, opening completely after the sun goes down and closing in midafternoon. After sunrise, they start to produce nectar.
  • Saguaro cacti produce ruby red fruits that are 2.4-3.5 inches (6-9 cm) long. The fruits contain a sweet, fleshy tissue and about 2,000 seeds.
saguaro cactus
saguaro cactus

Growing Saguaro Cactus

Saguaro cacti can be grown both indoors and outdoors, as they usually take between 20 and 50 years to reach only 3.3 feet (1 m) in height. Like all cacti, they are very simple to grow and care for, as they do not require too much attention.

They thrive in full sunlight, but extended periods of bright and hot sun may burn them. When growing them outdoors, plant them in an area where they can always bathe in bright and partial light during the summer. They can also do well in a heated greenhouse. If you want to grow them inside your home, choose a spot in front of west-facing or south-facing windows.

Saguaro cacti love warm temperatures and cannot tolerate frost conditions. They do not enjoy temperatures that drop below 60 °F (15 °C), so make sure you bring them indoors in early autumn. During the cold temperatures or winter, these cacti will be just fine in average room temperatures.

This species is a desert cactus, so it prefers to grow in a neutral, loamy, and well-draining soil. Plant your Saguaro cactus in a potting mix that is specially made for cacti and succulents or add some extra grit to an all-purpose potting soil. For optimal growth, you can also add a top layer of pebbles or gravel, as this will reduce the moisture levels of the soil and stabilize the cactus as it grows taller.

Flowers of the Saguaro cactus
Flowers of the Saguaro cactus

Although Saguaro cacti do not need fertilizers frequently, you can feed your plant once a year in spring. Fertilizing with cactus food will do the job, as it can help these cacti to complete their growth cycle. If you want to encourage growth, you can use a light liquid fertilizer during the growing season once every two or three weeks.

The most common pests that can affect your Saguaro cactus are mealybugs and scale insects. If you notice some signs of infestations, you need to quarantine your cactus and wipe it carefully with a cotton cloth dipped in rubbing alcohol. Also, you can prevent these infestations using organic pesticides or insecticides regularly.

These cacti have a different root system from other cacti. If you want to repot or transplant Saguaro cacti, their prominent tap root must be cut. It is a relatively simple process if you are careful or if you have someone to help you lift the cactus when it is older.

You should dig around the cactus at about one foot (30 cm) away from it until you discover several roots. Make sure you cut the roots at the bottom of the dug hole, leaving most of them intact. Take out the cactus gently and trim any unhealthy parts using sharp pruning shears. Before repotting, you need to leave the roots to dry for a few days. The ideal time for transplanting these cacti is at night as long as the temperatures are above 60 °F (16 °C).

Watering the Saguaro Cactus

Like all cacti, Saguaros store large quantities of water in their stems, so they are tolerant of long periods of drought. However, this species can grow and bloom much better when they receive enough water. Thus, if you want your cactus to produce some pretty flowers, you can easily achieve this by paying attention to the basic needs of your cactus.

During their growing season, from late March to September, these cacti need regular watering. When they are dormant, you can water them once or twice per month. The frequency of watering directly depends on the temperatures in which your cacti are growing.

No matter what season or climate conditions they experience, you always need to check the soil before the next watering. It is suggested to allow the mix to dry out slightly before you water them again.

Closeup of the Saguaro Cactus
Closeup of the Saguaro Cactus

Propagating Saguaro Cactus

Although this can be a process that shows results after a long period, the safest and easiest way to propagate Saguaro cacti is from seeds. But do not worry! You can prepare the propagation environment for your baby cactus in just a few minutes.

Choose a small or medium-sized container that has drainage holes and fill it with potting soil. You can look for any well-draining mix or simply purchase one that is suitable for growing cacti and succulents. Using a sharp pencil, make several tiny holes at about 1 inch away from each other and bury your Saguaro seeds in them. Cover the container with plastic wrap and poke some small holes in it.

Make sure you place the pot in a warm area that provides it with enough light but protects it from long periods of direct and full sunlight. Water the cactus seeds once every ten days and remove the plastic wrap after four to six weeks. Once this period has passed, you can water the cactus once every month.

You will start to notice tiny Saguaro cacti in about one or two years when each of them can be moved in their own pots. Have patience, gardener! When you see how cute these baby cacti are, you will know that they were worth the wait.

In Conclusion

Saguaro cacti can surely catch every passer’s eye. They look like swords or spears stuck in the ground and they will charm their surroundings with their exotic and exquisite bloomings. Plus! They are pretty simple to grow both indoors and outdoors.

These cacti will grow healthy and happy without too much effort on your part. All you have to do is plant them in a warm location with bright, indirect light and water them once in a while. Saguaro cacti make great life companions. They have a long lifespan, sometimes exceeding 150 years, and can remind you of the good old times spent together.

Miruna Secuianu

Miruna is an experienced content writer with a passion for gardening. She is the proud owner of an outdoor rose garden and an indoor collection of tiny succulents. She bought her first succulent 10 years ago - an adorable Echeveria Setosa. Now she owns more than 100 succulents and cacti of different colors, shapes, and sizes. Miruna is a versatile writer and, as you might have guessed, her favorite topic is gardening. Contact

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