The fishbone cactus (Epiphyllum anguliger), also known as the zig-zag cactus, is a highly sought-after houseplant recognized for its unique, deeply serrated, flat stems. Its appeal lies in this distinctive foliage and the potential for large, fragrant, nocturnal blooms, which typically open only at night. Understanding its native habitat is the first step in successful cultivation, as this species is not a desert plant but an epiphyte, or “jungle cactus.” This distinction means its care requirements are fundamentally different from arid-loving cacti.
Creating the Ideal Environment
The fishbone cactus thrives in bright light conditions but must be protected from intense, direct sun, especially during the afternoon. As an epiphyte, it naturally grows beneath the canopy of larger trees in its native Mexican rainforests, receiving filtered sunlight. Placing the plant a few feet away from an east-facing window or where it receives gentle morning sun prevents the soft stems from scorching. Scorch marks appear as bleached or browned patches, indicating cellular damage from UV exposure.
Standard indoor temperatures are well-suited for this plant, ideally maintaining a range between 65 and 75 degrees Fahrenheit. Consistent warmth is preferable; avoid placing the cactus near cold drafts from windows or air conditioning vents. Sudden temperature drops can stress the plant, potentially leading to stem damage or a reluctance to flower.
High atmospheric moisture is characteristic of the jungle environment this species evolved in, making humidity a significant factor in its health. The soft, flat stems benefit from moisture in the air, unlike desert cacti that have evolved thick, waxy skin to conserve water. Increasing local humidity can be achieved by placing the potted plant on a shallow tray filled with pebbles and water, or by grouping it with other houseplants.
Watering and Feeding Requirements
The watering schedule must balance the cactus’s preference for moisture with its susceptibility to root rot. Unlike desert cacti that tolerate long periods of drought, this species requires water once the top one or two inches of its potting medium feel dry to the touch. This partial drying prevents the fine, fibrous roots from suffocating in constantly saturated soil, which is the most common cause of plant failure.
When watering, saturate the entire soil volume until excess water drains freely from the bottom of the pot, ensuring all roots receive hydration. Insufficient watering, characterized by the potting medium drying out completely, causes the fleshy stems to shrivel and become limp. Conversely, stems that turn yellow or mushy at the base are exhibiting symptoms of persistent overwatering.
Fertilization should support the plant’s active growth phase, which runs from early spring through late summer. A balanced, water-soluble fertilizer, such as a 10-10-10 or similar ratio, should be applied every two to four weeks during this period. The solution should be diluted to half or even quarter strength to avoid burning the sensitive root system.
Nutrient intake is suspended during the cooler fall and winter months when the plant enters a period of semi-dormancy. Providing nutrients during this rest period is unnecessary and can lead to the accumulation of salts within the soil, negatively impacting root health.
Soil Potting and Seasonal Cycles
The substrate chosen must replicate the airy, well-draining conditions of its native arboreal environment. A standard potting mix is often too dense and retains too much moisture, so an amended blend is necessary for proper aeration. An ideal mix incorporates components like orchid bark, coarse perlite, and coco coir or peat moss to facilitate rapid drainage and oxygen exchange.
Repotting is required only when the plant becomes visibly root-bound, which usually occurs every two to three years. A porous material like unglazed terracotta is preferred because it allows excess moisture to evaporate through the pot walls. Repotting should be done into a container only one size larger, as an excessively large pot increases the volume of soil that remains wet.
The plant’s care regimen shifts with the changing seasons to align with its natural growth and rest phases. Spring and summer are the periods of vigorous growth, requiring consistent watering and regular feeding to support stem development. As daylight hours shorten in the fall, the plant begins to slow its metabolic processes in preparation for winter dormancy.
This winter rest period is important for encouraging the formation of flower buds, which appear in late winter or early spring. To induce blooming, growers reduce watering significantly and expose the cactus to slightly cooler temperatures, ideally between 50 and 60 degrees Fahrenheit, for several weeks. Once new growth or buds appear, the plant can be returned to its regular spring care schedule.
Common Issues and Solutions
Several houseplant pests can affect the fishbone cactus, with mealybugs and scale insects being the most frequent invaders. Mealybugs appear as small, white, cottony masses usually clustered in the crevices of the stems or where new growth emerges. Scale insects are identifiable as small, brown, immobile bumps firmly attached to the stems, where they feed on the plant’s sap.
For minor infestations, pests can be swabbed off using a cotton ball or swab dipped in isopropyl alcohol. If the problem is widespread, a horticultural oil, such as neem oil, can be applied to the affected areas, ensuring complete coverage to smother the insects. Repeated treatments are necessary to eliminate newly hatched pests.
Physical symptoms on the stems point to an environmental imbalance related to water or light. Limp, deflated, or wrinkled stems indicate underwatering or that the root system has failed due to previous overwatering. Conversely, stems that turn yellow or become soft and mushy are a sign of persistent excess moisture and the onset of stem rot.