Twisted cactus plants, with their unusual and captivating appearance, are popular ornamental choices. Their distinct growth pattern sets them apart from typical cacti, making them intriguing additions to any collection with unique sculptural forms.
The Science Behind the Twist
The distinctive “twisted” or flattened growth in these cacti is a biological phenomenon known as fasciation or cristation. This abnormal growth pattern stems from a broader, elongated apical meristem, the plant’s growing tip. Instead of a cylindrical stem, the meristem expands horizontally, leading to ribbon-like, fan-like, or contorted shapes.
Fasciation can arise from genetic mutations, hormonal imbalances, environmental stressors, or physical damage to the growing tip, such as from insects, frost, or mechanical injury. The result is a deviation from normal plant architecture.
Popular Twisted Cactus Varieties
Several twisted cactus varieties are sought after for their unique forms.
Cereus peruvianus ‘Monstrosus’, the Monstrose Apple Cactus, features bumpy, knobby stems with an irregularly undulating pattern. Its grey-blue stems twist and fold, creating a sculptural effect.
Mammillaria elongata ‘Cristata’, known as the Brain Cactus, has convoluted, brain-like ridges and small, fine golden or white spines that give it a grayish appearance.
Myrtillocactus geometrizans ‘Cristata’, or Cristate Blue Candle, is prized for its fan-like, wavy growth and striking blue-green color. Each plant develops its own intricate pattern of folds.
While some cacti, like Cereus forbesii ‘Spiralis’, exhibit natural spiral growth, this differs from the flattened or fan-like growth of fasciated forms.
Caring for Twisted Cacti
Light
Twisted cacti thrive in bright, indirect light. Some varieties tolerate direct morning sun, but intense midday sun may require shading to prevent scorching.
Watering
Allow the soil to dry completely between waterings to prevent root rot. Overwatering is a common issue, so it is better to underwater. During winter, reduce watering frequency, only watering if the plant shrivels and temperatures are above 50°F (10°C) to avoid rot.
Soil and Drainage
A well-draining soil mix is essential. Use a specialized cactus or succulent mix, amended with perlite, pumice, or coarse sand, to promote proper drainage and aeration. Pots with drainage holes are also important to prevent water accumulation at the roots.
Temperature and Humidity
Twisted cacti prefer average room temperatures, between 60°F and 75°F (16°C and 24°C), and are sensitive to frost. They tolerate dry conditions and do not require high humidity.
Fertilization and Repotting
During the growing season (spring and summer), fertilize monthly with a diluted cactus fertilizer. Repot every one to two years or when the plant outgrows its container, allowing roots to settle in dry soil for a week before the first watering.
Common Problems and Solutions
Rot
Rot is a common problem, primarily caused by overwatering or poor drainage. Symptoms include mushy, discolored stems, a foul odor, or wilting. To address rot, immediately remove the plant, trim away all affected parts with a sterilized knife, and allow healthy roots to air dry before repotting in fresh, well-draining soil.
Pests
Pests like mealybugs, scale insects, and spider mites can infest twisted cacti. Mealybugs appear as small, cottony masses, scale insects as small, armored bumps, and spider mites cause yellowing or scarring with fine webbing. For mealybugs and spider mites, a strong stream of water or cotton swabs with rubbing alcohol can dislodge them. Insecticidal soaps or neem oil are also effective treatments.
Reversion and Stunted Growth
A fasciated cactus may revert to normal growth, producing cylindrical stems instead of the characteristic twisted form. If normal growth appears, prune these sections to encourage the desired crested growth. Stunted growth indicates insufficient light or nutrient deficiencies, remedied by adjusting light exposure and ensuring regular fertilization during the growing season.