Most plants are named after their appearance and the Ferocactus is a good example. This fierce-looking type of cactus can intimidate with its dense, rigid spines covering the entire rounded plant. But there’s more to this cactus than its name.
- What is a Ferocactus?
- Origin and Distribution
- Growing and Caring for Barrel Cactus
- Popular Species of Ferocactus
- F. emoryi subsp. rectispinus, Long-spined Barrel Cactus
- F. glaucescens, Glaucous Barrel Cactus
- F. latispinus, Devil’s Tongue Cactus
- F. macrodiscus, Candy Cactus
- F. wislizenii, Compass Cactus
The Ferocactus is an impressive house and landscape plant and can be a practical and valuable resource in its xeric environment. Growing and caring is also rather straight-forward so keeping it as a house plant is definitely worth a shot.
What is a Ferocactus?
The Ferocactus is a genus of plants belonging to the cactus family. Like the Echinocactus, cacti under this group are commonly referred to as Barrel cactus because of the characteristically large stout stem that can be rounded to cylindrical in form. These cacti are usually unbranching with ridges called ribs running down the stem but there are several species with smaller stems and form clumps.
In the wild, their height can range from 2 to 10 feet (3 meters) and the diameter from 18 to 33 inches (45 to 83 cm).
Young plants grown indoors are solitary and small enough to grow in containers. Ferocactus species have 20 to 28 ribs and their root system is shallow, reaching up to 8 inches (20 cm) deep.
The Barrel cactus is covered with hard large spines that protect it from thirsty creatures and small finer spines that help the plant deflect the desert sunlight. Their color ranges from white to gray and yellow to pink and their shape may be straight or hooked. They are even traditionally used as a fishing hook by the Native Americans (1).
Like most cacti, the Ferocactus bears amazing flowers. They appear at the apex of the plant in a striking ringed cluster. They are funnel-like in shape—the size of 1 to 2 inches in diameter when in full bloom.
The petals come in shades of red, orange, pink, and yellow, creating a soft visual accent against the green plant during the early summer in May. The resulting fruits look like small pineapples clustered on top of the plant. They are fleshy but dry and inside are thousands of tiny brown to black seeds (2).
Another nickname for the Ferocactus is “The Traveler’s Friend’ because in the desert, it serves as a moisture reservoir for a parched traveler in dire need of water. However, research says that the stored moisture from the plant is too alkaline to drink.
Origin and Distribution
The Barrel cactus originated from the Sonoran Desert in North America. The group of plants is native and widely distributed in the southern United States and Mexico, occurring at elevations from 0 to 1,200 meters above sea level (2).
These plants thrive in flat sandy areas and porous rocky soils with limited water and bright sun.
Many species of Ferocactus are now commercially sold like f. fordii, f. latispinus, and f. wislizenii. They make unique house plants in pots and dish gardens and are attractive solitary cacti for themed landscape and gardens.
Growing and Caring for Barrel Cactus
Light and Water
Almost all cacti prefer exposure to bright sunlight for most of the day. When growing a barrel cactus at home, position them under full sunlight, and gradually introduce a little shade during the high heats of summer.
Note that even though they are desert plants, most cacti that come from nurseries are already acclimatized and may respond poorly under extreme heat.
On the other hand, insufficient sunlight exposure for long periods will cause the cactus to etiolate and appear like it’s being stretched out at the center. Transition this plant into the right light condition gradually to avoid scorching and further damage to the plant.
Watering a cactus is almost unnecessary, considering the little to no moisture that they receive in their natural habitat. However, landscape and indoor barrel cactus can benefit from light watering, ideally rainwater. From spring to early fall, water thoroughly when the top ¼ inch (2 cm) of the soil is dry. Come late fall to winter, stop watering the plant and keep the soil dry (3).
Temperature and Humidity
Because they live in hot arid deserts, cacti are used to high temperatures and humidity, but they are fairly tolerant of changes. They can continue growing between 64 and 86 °F (10-30 °C). Some species like F. wislizeni are frost-sensitive and are prone to freeze-damage (4).
They appear as orange marks that fade to gray scars.
Pests and Diseases
Mealybugs and scale insects are the most common pests appearing on cacti. When kept unattended, they leave light to deep scars on the plant, and in severe cases, cause the plant to die.
They can be difficult to manually remove because of the spines and these pests latch in the grooves of the cactus. They can be removed using tweezers and brush or spray with isopropyl alcohol or apple cider vinegar diluted in water.
A barrel cactus, especially one grown at home, is susceptible to rotting. This is primarily due to wet soil and poor drainage (3).
To avoid this, follow the recommended watering regimen. Use a well-draining, porous potting medium and make sure that the pot or container has sufficient drainage holes.
Propagation and Maintenance
Ferocactus species are usually solitary, growing with a single stem that’s why they can only be propagated through seeds (2).
Flowering usually takes place when the plant is 2 to 3 years old, so seeds are not available until then and when planted, germination can take a week to 5 months, depending on external and internal factors.
Reproducing barrel cacti takes perseverance but the resulting plant and blooms are definitely rewarding.
There are few clustering species like F. robustus and F. glaucescens that produce clusters and these types can be suitably propagated using the rooted offsets. When dealing with cactus, make sure to wear the proper protective equipment to avoid injury to yourself and the plant.
Once in 2 or 3 years, it is recommended to repot a barrel cactus. This is to make sure that the soil remains airy and the roots able to breathe. Indoor cacti being irrigated with tap water are prone to mineral build up in the soil over time so repotting avoids the harm in this deposit.
Fertilizer application on a Ferocactus should be performed during the growing season. A balanced 10-10-10 fertilizer diluted to ¼ strength will boost the plant’s overall growth and keep it thriving (4).
Popular Species of Ferocactus
F. emoryi subsp. rectispinus, Long-spined Barrel Cactus
An apt name for this Ferocactus, it boasts long red spines all over a barrel-shaped stem reaching up to 10 inches (25 cm) in length. In summer, it produces elegant large pale yellow flowers.
F. glaucescens, Glaucous Barrel Cactus
One of the few clustered barrel cacti, this plant is rounded when young and turns more cylindrical upon maturity. The body is bluish-gray with defined ribs covered in yellow spines. It also bears funnel-like yellow flowers.
F. latispinus, Devil’s Tongue Cactus
This striking cactus got its common name from the way the spines appear. In each set of star-like red spines is a larger, more curved one. The bluish-green stem is more rounded than most Ferocactus and in summer, purplish-pink flowers appear atop the plant.
F. macrodiscus, Candy Cactus
The candy cactus is low-growing with a dome-shaped gray-green stem. Covered in cream-colored spines, the plant comes alive once the showy white and pink striped flowers appear in spring.
F. wislizenii, Compass Cactus
The compass cactus is stout and slow-growing and becomes columnar as it matures. Its defined ribs revolve about as the stem elongates and the plant is covered in reddish curved spines, hooked at the tip. The flowers vary in color from red to yellow to orange.
(1) Gauna, F. Barrel Cactus (Ferocactus sp., Britt & Rose). United States Department of Agriculture. 2020. (online) https://www.fs.fed.us/wildflowers/plant-of-the-week/ferocactus_sp.shtml.
(2) Ferocactus wislizeni. Arizona State University. 2020. (online) http://www.public.asu.edu/~camartin/plants/Plant%20html%20files/Ferocactuswisilzenii.html.
(3) Bailey, F. & Allaway, Z. Practical Cactus and Succulent Book. Penguin. 2019. P. 224.
(4) Matthews, R. Ferocactus wislizeni. 1994. Fire Effects Information System, USDA. (online) https://www.fs.fed.us/database/feis/plants/cactus/ferwis/all.html.
*image by Dynamoland/depositphotos