8 Types of Oreocereus Cactus [With Pictures]
Known only from high altitudes in the Andes, the Oreocereus cactus is a genus of the Cactaceae family. In Greek, oreo means mountain, and in New Latin, cereus means torch or wax, resulting in its name.
A few species of this genus of cactus are sometimes referred to as old-man cacti because of their woolly white fuzz (modified spines). A few species are also called the old man of the Andes.
1,000 Types of Cacti [With Pictures]
Types of Oreocereus Cactus
Oreocereus celsianus, or the “old man of the Andes” is a columnar, cactus growing in clumps that, in the wild, may reach and exceed 3 m of height (but usually less than 2 m tall). It is difficult to see the shape of the ribbed stem, as it is thickly clothed with silky white hairs.
Oreocereus doelzianus is a very hairy tall growing columnar cactus. The bright red flowers are borne towards the end of the stems in the pseudocephalium and appear freely at an early age.
Oreocereus hempelianus is a short cylindrical cactus with dense short brown spines and bright purple/red flowers when mature. This species is quite variable in spination and has received numerous unnecessary names of no botanical value, representing no more than local phenotypes.
Oreocereus leucotrichus is a small shrubby columnar cactus, forming dense broad clumps covered in spines. It is a much variable species. It has 10-15 (or more) ribs covered with with abundant white to black silky hairs 5-10 cm long, thicker on the more recent vegetation.
Oreocereus trollii also known as the Old Man of the Andes is a shrubby columnar cactus with fine, completely enveloping hair and powerful coloured spination, but much dwarfer in stature than Oreocereus celsianus. Young plants of Oreocereus trollii are also very popular in small cacti collections.
How to Care for Oreocereus cactus
The Oreocereus cactus grows well when it has bright light all through the day. Full to partial sunlight with good ventilation is best for the growth of the Oreocereus cactus and it does better outdoors than indoors.
If you’re growing Oreocereus cacti outdoors in your garden, then choose a spot where the plant gets plenty of sunlight.
If you’re growing the plant in a pot or container indoors, then make sure to place the plant in a south-facing window that receives ample sunlight.
The Oreocereus cactus must be watered well in the summer months, during the vegetative period. Make sure to water the plant regularly, but you must allow the surface of the soil to dry up completely before watering it again.
During the autumn and winter months, the plant must be kept dry and it must be just watered to prevent the plant from shriveling. Avoid watering the succulent on days when it is humid, overcast or on cold winter days.
Over-watering the plant or keeping it wet during winter or when the weather is humid can cause it to rot.
The Oreocereus cactus grows best in rich, acidic soil with pH levels between 5.0 to 6.5. The soil must contain around 1/3rd part grit or equal parts of leaf mulch and coarse sand and be well-draining to prevent root rot.
When you consider the feeding requirements, the Oreocereus cactus must be fertilized regularly, once in one to two weeks during summer and spring. You can either use proprietary cactus food or a balanced liquid fertilizer.
Native to the arid mountainous areas, the Oreocereus cactus is predominantly an outdoor plant and does better when planted in outdoor gardens. The succulent does well in warm climates and grows best in USDA hardiness zones 7a to 11b, with temperatures around 20°F.
In colder areas, it is better to grow the plant indoors, as long as it receives plenty of sunlight and is kept dry. It is best not to expose the plant to temperatures less than 20°F, even if the area is protected and well-ventilated.
If you live in an area where the winter months are cold and wet, then it is best to keep Oreocereus cacti in a sunny greenhouse where the plants are protected and dry from the wet conditions.
In conditions of very high humidity, the plant is particularly sensitive to rot and so you must protect it from excess humidity, especially during the winter months.
Pest and Diseases
In general, Oreocereus cacti is healthy and is resistant to diseases, but it may be susceptible to pests like mealybugs and red spiders.
Oreocereus cacti does not require any pruning.
Potting and Repotting
You must re-pot the Oreocereus cactus the first time you bring it from the store. When the roots of the Oreocereus cactus become cramped in the container, then you should re-pot the plant, preferably in spring.
The plant must be repotted once in 1-2 years to provide fresh soil. When you re-pot the Oreocereus cactus, avoid watering the plant for around 1-2 weeks.
How to Propagate Oreocereus Cactus
Oreocereus cacti can be propagated by seeds or cuttings. Since it is a slow-growing plant, it is generally not recommended to grow Oreocereus cacti by seeds.
You can collect the seeds of the Oreocereus cactus from over-ripe fruits and plant them in March. To propagate the plant using its seeds, the seeds must be planted in well-draining soil and kept at a high temperature and humidity.
You can also propagate the Oreocereus cactus via cuttings. For this method, during spring, make a cut and allow it to dry. The cut surface will dry and form a callus. Place the cutting in a soil, pumice and sand mixture.
You can increase the success of propagation via cuttings by making more than one cutting at the same time.