The Fish Cactus (Epiphyllum anguliger) is a captivating houseplant known for its distinctive appearance and straightforward care. Its unique, deeply lobed stems give it common names like Fishbone Cactus, Zigzag Cactus, and Ric Rac Cactus, making it an intriguing indoor plant. This plant also produces beautiful, fragrant night-blooming flowers. Originating from the rainforests of Mexico, this epiphytic plant is low-maintenance.
Understanding Your Fish Cactus
The Epiphyllum anguliger is recognized by its flattened, succulent stems with pronounced, alternating lobes. These green, fleshy stems store water, contributing to the plant’s drought tolerance. Unlike desert cacti, the fish cactus is an epiphyte, growing on other plants like tree trunks and branches rather than in soil. In its native habitat, it uses aerial roots to attach to host plants, absorbing moisture from the air and nutrients from decaying organic matter.
Optimal Care Practices
Light Requirements
The fish cactus thrives in bright, indirect light, mimicking its natural environment under a tree canopy. Placing it near a north or east-facing window is ideal, providing ample brightness without harsh direct sun. Too much direct sunlight, especially during the hottest parts of the day, can scorch its stems, causing yellowing or brown spots. If grown outdoors, a spot with morning sun and afternoon shade is suitable.
Watering Needs
Unlike desert cacti, Epiphyllum anguliger prefers consistent moisture. Water the plant thoroughly when the top two to three inches of soil feel dry to the touch. Allow excess water to drain completely from the pot to prevent root rot. During cooler winter months, reduce watering frequency, allowing the soil to dry out more between applications. Signs of underwatering include shriveling or limp stems, while overwatering can lead to mushy stems and root rot.
Soil and Potting
A well-draining, airy potting mix is suitable for the fish cactus, reflecting its epiphytic nature. A blend might include commercial cactus or succulent soil mixed with perlite, orchid bark, and peat moss. This combination provides both drainage and some moisture retention. When repotting every one to three years, choose a container with drainage holes that is only slightly larger than the previous one. Terracotta pots can be beneficial as they help regulate moisture by absorbing excess water.
Temperature and Humidity
The fish cactus prefers warm, humid conditions, similar to its native rainforest environment. Ideal temperatures range between 60°F to 78°F (16°C to 26°C), though it can tolerate temperatures as low as 50°F (10°C) in winter. Maintaining humidity levels above 60% is beneficial, achieved by misting regularly or placing the pot on a pebble tray filled with water. Avoid sudden temperature fluctuations and cold drafts, which can stress the plant.
Fertilizing
During the active growing season, fertilize your fish cactus every four to six weeks. Use a balanced, water-soluble fertilizer or a specialized cactus fertilizer, diluted to half strength. A low-nitrogen fertilizer can encourage blooms. Avoid fertilizing during the fall and winter months when the plant enters its dormancy period.
Encouraging Blooms
To encourage flowering, provide specific conditions. The plant benefits from a cool winter rest period, with temperatures ideally between 50°F and 60°F (10°C to 16°C) and reduced watering. This temperature fluctuation, along with a slight reduction in light, helps stimulate bud formation. Bright, indirect light and consistent, but not excessive, watering during the growing season also contribute to flowering. Once flower buds begin to form, a fertilizer higher in phosphorus or a “tomato-type” fertilizer can be applied every two weeks until most buds open.
Propagation Techniques
Propagating the fish cactus is relatively simple, done through stem cuttings. Select a healthy stem section, about 6 to 12 inches long, from the parent plant. Allow the cut end to “callous” or dry for a few days to a week before planting; this prevents rot.
Once calloused, insert the cutting about one to two inches deep into a well-draining potting mix, similar to that used for mature plants. Keep the soil lightly moist, but not soggy, as the cutting develops roots, which occurs within a few weeks. Alternatively, cuttings can be rooted in water before transplanting to soil once roots are several centimeters long. Spring and summer are the best times for propagation, for optimal rooting and new growth.
Troubleshooting Common Issues
Yellowing or browning of stems can indicate too much direct sunlight or overwatering. If stems appear soft, mushy, or show signs of black rot, this indicates root rot caused by excessive moisture. Ensuring proper drainage and allowing the soil to dry between waterings can prevent these issues. Leggy or stretched growth suggests insufficient light; moving the plant to a brighter, indirect light location promotes healthier, more compact growth.
While generally pest-resistant, fish cacti can occasionally encounter mealybugs, aphids, or fungal spots. Inspect the plant regularly for pests and treat them with insecticidal soap or neem oil if found. Fungal spots, appearing as brown, slightly raised areas, can be managed by ensuring good air circulation and avoiding water sitting on the stems.