The term “sea cactus” is an informal descriptor for certain cacti with unique growth habits and appearances. Unlike typical desert cacti, these plants thrive in different environments. This guide provides information on identifying and caring for these distinctive plants.
Understanding the “Sea Cactus” Term
The term “sea cactus” is an informal descriptor, not a recognized scientific name. It typically refers to epiphytic or lithophytic cacti from tropical and subtropical regions, unlike arid desert cacti. These plants naturally grow on other plants, like trees, or on rocks, rather than rooting in soil.
The primary plant genera identified as “sea cacti” include Rhipsalis (Mistletoe Cactus) and Epiphyllum (Orchid Cactus). These plants usually feature segmented, flattened, or cylindrical stems and lack the prominent spines seen on desert cacti. Their natural habitat is typically humid forests, which contributes to the “sea” association due to high moisture levels.
Care Guide for “Sea Cacti”
Light Needs
“Sea cacti” thrive in bright, indirect light, mimicking their native forest canopies. Place them near an east-facing window or a few feet from a south or west-facing window for suitable illumination. Avoid direct, harsh sunlight, as it can scorch their delicate stems and cause permanent damage.
Watering Practices
These plants require more consistent moisture than desert cacti due to their humid origins. Water them when the top inch or two of their potting mix feels dry. Well-draining soil is important to prevent waterlogging and root rot.
Soil Requirements
The ideal potting mix for “sea cacti” is airy, well-draining, and rich in organic matter, reflecting their epiphytic nature. A suitable blend includes standard potting soil combined with perlite, orchid bark, or coco coir. This combination promotes excellent drainage, moisture retention, and aeration for healthy root development.
Temperature and Humidity
“Sea cacti” prefer warm temperatures, generally 60-80°F (15-27°C), and high humidity. Mimic their native tropical conditions by placing the plant on a pebble tray filled with water, ensuring the pot does not sit directly in the water. Regular misting or a room humidifier can also help maintain adequate humidity levels.
Fertilizing
During their active growing season (spring and summer), “sea cacti” benefit from regular fertilization. Apply a balanced liquid fertilizer, diluted to half strength, every two to four weeks. Reduce or cease fertilization in fall until the next growing period as light levels decrease.
Common Problems and Solutions
Overwatering often leads to root rot, indicated by mushy stems or yellowing foliage. Adjust watering frequency to allow the soil to dry adequately between waterings; in severe cases, repotting into fresh, dry soil may be necessary. Conversely, underwatering can cause stems to appear shriveled or limp, signaling a need for more consistent moisture.
Insufficient light results in pale stems and lack of new growth, requiring a brighter, indirectly lit location. Too much direct sun can scorch stems or cause reddish discoloration, indicating a need for a shadier spot. Common houseplant pests like mealybugs or scale can be managed with organic pest control methods such as neem oil or insecticidal soap.
Propagating “Sea Cacti”
Propagating “sea cacti” is straightforward using stem cuttings. Select a healthy stem segment with at least two to three nodes. After cutting, allow the segment to dry and form a callus over the cut end for one to two days.
Once calloused, plant the cutting in a well-draining potting mix, similar to the adult plant’s soil. Keep the soil slightly moist, not waterlogged, and place the pot in indirect light. The ideal time for propagation is during the plant’s active growing season (spring or summer).