The Lobster Flower, Nematanthus gregarius, is an ornamental plant known for its distinctive blooms. These unique flowers resemble tiny, plump fish, lending the plant its common names like Goldfish Plant or Clog Plant. Its appealing appearance makes it a popular choice for indoor gardening, adding vibrant color and unusual form to any space.
Understanding Lobster Flower
Nematanthus gregarius is a perennial sub-shrub with a trailing or bushy growth habit, suitable for hanging baskets with cascading stems. Its leaves are small to medium-sized, oval-shaped, and are glossy, dark green, and waxy. Its most striking feature is its bright orange-red, tubular flowers, which have a unique pouch-like shape, strongly resembling a goldfish. These blooms, typically one inch long, often appear in clusters of up to three.
Originally native to the tropical forests of Brazil, Nematanthus gregarius is accustomed to warm, humid environments, often growing as an epiphyte on trees. While it thrives outdoors in USDA zones 10 and 11, it is commonly cultivated as an indoor houseplant in cooler climates due to frost sensitivity. Its moderate size and preference for humidity also make it a suitable plant for terrariums.
Cultivating Lobster Flower
Lobster Flowers flourish in bright, indirect light for abundant blooms. An ideal spot is near an east or north-facing window, for filtered sunlight without harsh direct sun. Direct afternoon sunlight can scorch leaves, while insufficient light leads to leggy growth and fewer flowers. A grow light can supplement light, especially in winter or darker environments.
Consistent moisture is important for Lobster Flowers, but they are susceptible to root rot if overwatered. Water when the top one to two inches of soil feel dry, ensuring the soil remains moist but not waterlogged. Using room temperature, filtered, or distilled water prevents issues from tap water chemicals. Allow excess water to drain completely to avoid soggy conditions.
A well-draining, peat-based potting mix is suitable for Nematanthus gregarius. A good mix includes perlite or vermiculite for drainage and aeration, or a mix designed for African Violets or epiphytic plants. The plant prefers to be slightly pot-bound, so repotting is needed only every one to two years, preferably in spring, into a slightly larger pot.
Lobster Flowers prefer warm conditions, with temperatures between 65°F and 80°F (18°C to 27°C). They are sensitive to cold drafts and temperatures below 50°F (10°C), leading to leaf drop and stress. High humidity levels are also beneficial for this tropical plant; misting, using a humidity tray, or a humidifier maintain humidity.
During the active growing season in spring and summer, feed your Lobster Flower every two to four weeks with a balanced liquid fertilizer diluted to half strength. A 10-10-10 fertilizer or one formulated for flowering plants promotes healthy growth and blooming. Reduce or cease feeding during the dormant period in fall and winter.
Propagation and Pruning
Propagating Lobster Flower is done through stem cuttings. Select healthy, non-flowering stem tips approximately four to six inches long. Remove lower leaves, leaving a few at the top, and optionally dip the cut end in rooting hormone. Keep them in a warm, humid environment with indirect light until roots develop (a few weeks).
Regular pruning maintains a bushy, attractive shape and encourages prolific flowering. Trimming stems after blooming promotes new growth and branching. Remove spent flowers, yellowing leaves, or leggy stems to keep the plant compact and healthy. When pruning, make clean cuts just above a leaf node, and avoid removing more than 30% of the foliage at one time.
Troubleshooting Common Issues
Leaf drop or yellowing leaves on a Lobster Flower indicate watering or environmental issues. Overwatering, leading to soggy soil and root rot, commonly causes yellowing leaves and wilting. Conversely, underwatering also causes leaves to wilt and drop. Sudden temperature changes, cold drafts, or insufficient humidity also stress the plant, resulting in leaf loss.
A lack of blooms points to insufficient light, a primary requirement for flowering. Adequate bright, indirect light for at least 9 to 13 hours daily stimulates flowering. Improper fertilization or plant immaturity can also affect bloom production.
Lobster Flowers can be affected by common houseplant pests like mealybugs, spider mites, and aphids. These pests weaken the plant by sucking sap. Early detection and treatment are important; organic solutions like insecticidal soaps or neem oil are effective.
Leggy growth, with long, stretched stems and sparse foliage, results from insufficient light. To encourage a compact, bushy appearance, provide brighter indirect light and regular pruning. Pinching back new stem tips also promotes side branching, leading to a fuller plant.