The Fishbone Cactus (Epiphyllum anguliger), also known as the Ric Rac or Zig Zag Cactus, has become a widely favored houseplant due to its distinctive, saw-toothed stems. This species is an epiphyte, meaning it naturally grows on the surface of other plants in its native Mexican rainforest environment, which gives it needs distinct from desert cacti. Although often considered low-maintenance, owners can encounter a few common issues that require specific troubleshooting to maintain the plant’s health.
Water-Related Distress
Watering is the most frequent challenge for the Fishbone Cactus. Overwatering is the leading cause of decline, often resulting in a condition known as root rot, where the roots suffocate and decay due to persistently saturated soil. Symptomatically, this appears as mushy, blackened, or yellowing stems, often starting near the soil line, and a general loss of structural integrity as the plant collapses.
If root rot is suspected, immediate action involves unpotting the plant and inspecting the roots, cutting away all compromised, dark, and soft tissue with sterile shears. The plant must then be repotted into a completely dry, highly porous substrate to prevent further fungal or bacterial proliferation. This species requires a well-aerated mix, ideally composed of components like orchid bark, perlite, and a small amount of potting soil, to mimic the fast-draining debris pockets it would inhabit in a tree canopy.
On the opposite end of the spectrum, underwatering causes the stems to lose turgor pressure, appearing thin, deflated, or wrinkled along their zig-zag edges. This shriveling is the plant drawing on its internal water reserves and is often easily corrected with a thorough soaking until water drains from the bottom of the pot. Owners should allow the top one to two inches of the potting mix to dry completely before rewatering.
Pests That Target Fishbone Cacti
While the Fishbone Cactus is relatively robust, it can attract a few specific sap-sucking pests. Mealybugs are a common culprit, recognizable as small, cottony white masses usually nestled in the crevices and nodes of the zig-zag stems. These pests feed on plant sap, leading to stunted growth and a sticky residue called honeydew.
A localized mealybug infestation can be treated by dipping a cotton swab in 70% isopropyl alcohol and gently wiping away the visible insects. For a more widespread issue, the plant can be treated with a thorough spray of horticultural soap or neem oil, ensuring coverage of all stem surfaces. Scale insects appear as small, hard, brown or gray, dome-shaped bumps that adhere tightly to the stems and do not move.
Scale insects are difficult to treat due to their protective shell, requiring manual removal by scraping them off gently with a fingernail or a soft brush. Following manual removal, consistent application of neem oil or horticultural soap is necessary to target the mobile crawler stage of the insects. A proactive inspection routine helps prevent these pests from establishing a foothold and transferring to other houseplants.
Environmental Stress and Failure to Bloom
Despite being a cactus, this plant is not suited for intense, direct sunlight, which causes a form of damage known as light burn. Symptoms of light burn include stems that turn yellow, red, or develop bleached, scorched patches.
The plant thrives in bright, indirect, or filtered light, making placement near an east or north-facing window ideal. The plant prefers stable conditions between 61°F and 77°F. Exposure to cold drafts or temperatures below 50°F can cause stress and stem collapse.
An intentional period of environmental stress is required to trigger bud formation. This process involves a cool, dry rest period, typically in late fall or early winter, where temperatures are kept cooler, ideally between 50°F and 60°F. During this time, watering is significantly reduced, only providing moisture when the soil is completely dry, which mimics the natural seasonal cycle required for the plant to transition into its blooming phase.