Nematanthus (Goldfish Plant): Exotic Indoor Care Guide

The name comes from two Greek words: nema (“thread”) and anthos (“flower”). This plant got its name because of its appearance: in many varieties, orange, pink, yellow, or red blooms sit on a thin, long flower stalk. There is also a popular belief that keeping a nematanthus at home brings prosperity and family happiness. Many growers also appreciate it as a houseplant that helps make indoor spaces feel fresher.

Description

Nematanthus (also sold under the older name Hypocyrta) is a trailing perennial that can become a true showpiece in your home.Its graceful, long stems are covered with abundant blooms that cascade beautifully from a hanging planter.

There are several popular varieties of this plant:

Wettsteinii (often called the “goldfish plant”). This is one of the most popular and eye-catching types, with bright red flowers that shift into orange tones. The small blooms look glossy, almost as if they were coated with wax. Because of their unusual shape, this plant is commonly nicknamed the “goldfish plant.” Upright shoots can grow up to about 35 in (90 cm) tall. With proper indoor care, it can bloom from early spring through late fall.

Coin-leaf nematanthus. This variety stays miniature in size. It is an epiphytic, vine-like plant with only a small number of branches. The light-green leaves are rounded and fleshy; like the stems, they are covered with fine hairs. Bright red buds have a yellow “lip” that darkens toward the throat. After the blooming cycle ends, the plant can drop all of its leaves.

Nematanthus gregarius. A compact plant with twining stems. In nature, it can be found in the wild forests of Brazil. The flowers are orange-yellow. The small, glossy leaves often have burgundy or purple tones on the underside. Young plants may have upright stems at first, but later the stems begin to arch and cascade. That’s why growers usually plant it in hanging baskets.

Riverside nematanthus. This type stands out with its unusual lemon-yellow buds. If you add a support to the planter, the vine can be trained to grow in the direction you want. Large, glossy leaves (up to about 4 in / 10 cm long) grow in pairs. On the underside, the green color shifts into a reddish tone. The open flowers resemble small funnels, with a noticeable bulge on one side. Blooming period: April through October.

Nematanthus fritschii. A fairly large variety that can reach about 24 in (60 cm) in its natural environment. Its large, glossy leaves grow up to about 3.1 in (8 cm) long. As the plant matures, the stems begin to trail downward. Bright pink flowers are funnel-shaped and covered with soft fuzz. Flower size: up to about 2 in (5 cm).

“Long-legged” nematanthus. A vine-like shrub with broad, soft, light-green leaves growing in pairs; the leaves can reach up to about 4 in (10 cm) across. Large coral-colored flowers appear singly, though sometimes multiple buds form from the same leaf axil.

Indoor Care Guide

This tropical plant has only recently become popular as an indoor houseplant.Because of this, indoor growers are still learning and sharing the best practices for its care.

To keep your nematanthus healthy and thriving, you will need to put in a little effort, but it pays off when you see those spectacular blooms pop against the bright green foliage. In its native habitat within the tropical forests of Brazil, the plant usually blooms only during the summer. However, when grown indoors under the right conditions, it can bloom for much longer—from early spring straight through to late autumn.

Potting and Soil

Because the goldfish plant is naturally epiphytic (growing on trees rather than in the ground), its root system is relatively small and shallow, meaning it requires a shallow container. The roots actually prefer to be slightly root-bound to produce the best blooms. Hanging baskets are the most common choice. Often, several cuttings are planted in one pot for a fuller look. During its first few years, the plant should be repotted annually, either in spring or fall. When repotting, only go up one pot size (about 0.5 to 1 inch / 1.2–2.5 cm wider). Excellent drainage holes in the container are an absolute must.

Temperature Requirements

Maintaining the right temperature for a goldfish plant is crucial, as it is a tender tropical. In the winter, the ideal room temperature should sit around 60°F (15°C). Dropping much below this can quickly stress the plant. If the temperature falls to 45°F (7°C), the plant may begin to die back and lose all its leaves. In the spring, when the plant begins to actively grow and bloom, keep the temperature steady between 65°F and 77°F (18–25°C).

However, the “goldfish plant” doesn’t enjoy extreme heat either. At temperatures around 80°F (27°C) or higher, the tips of the leaves may dry out and curl. Never expose the plant to cold drafts or AC vents, as sudden temperature swings and wind can be fatal to this sensitive houseplant.

For optimal health and blooming, the plant prefers nighttime temperatures to be about 10 degrees Fahrenheit (5°C) cooler than during the day.

Watering

From spring to early autumn, nematanthus requires regular, thorough watering. In winter, you should significantly reduce the frequency and volume of water, while moving the plant to a slightly cooler room. Always use room-temperature, filtered (or overnight-rested) water. Water only when the top inch or two of the soil feels dry to the touch. Varieties with larger leaves generally need slightly more water. During the heat of summer, a popular watering method is to bottom-water the plant by placing the pot in a basin of water for 10–15 minutes, then letting it drain completely.

Humidity

During the summer, many growers recommend misting the plant and the air around it with warm water. Alternatively, you can place the pot on a humidity tray filled with wet pebbles (ensuring the pot itself doesn’t sit directly in the water) to provide a steady source of ambient moisture. Misting is generally unnecessary during the winter months.

Fertilizer

Nematanthus should be fertilized about twice a month throughout its active growing season (spring and summer). Standard liquid houseplant fertilizers or bloom-boosting formulas work well. When autumn arrives, stop feeding the plant entirely and wait until the following spring to resume.

Blooming

When healthy and kept in the right conditions, a goldfish plant will bloom abundantly and for a long time. The first buds usually form in March, and the last ones fade around mid-November. Experienced growers note that with the addition of grow lights, the plant can even bloom through the winter. However, this is generally not recommended, as continuous, year-round blooming exhausts the plant’s energy reserves. To ensure your plant blooms heavily during its natural season, follow these tips:

• Keep the pot small; the roots need to feel slightly root-bound to trigger blooming.
• Buds form best in bright, indirect, but heavily diffused light.
• Fertilize the plant consistently during the growing season and water it properly, but never allow water to sit at the bottom of the pot.
• You must periodically prune older branches, as flowers only develop on new growth.
• Provide the plant with a proper winter rest period so it can gather strength for the next season.

Pruning and Dormancy

To encourage intense blooming, a goldfish plant must be pruned every year. It is highly recommended to do this in the fall, right after the blooming cycle has ended. Pruning rejuvenates the plant and helps maintain its overall health. First, remove any weak, thin, or leggy branches. To stimulate branching and the formation of new shoots (where the flowers will grow), growers should also pinch back younger stems. Older shoots can be cut back by half, while younger ones can be trimmed by a third. You can save these healthy cuttings to propagate new plants. If you used grow lights during the winter and the plant continued to grow aggressively, you can do a second light pruning in the spring.

Once the nematanthus finishes blooming, trim back the excess growth and allow it to enter its dormancy period. Ideal conditions for this rest phase include: a slightly cooler room, plenty of bright indirect light, zero fertilizer, and significantly reduced watering.

Diseases and Pests

If the care requirements for nematanthus are ignored, the plant's defenses weaken, making it susceptible to various fungal diseases and pest infestations.Because the goldfish plant has thick, fleshy, and juicy leaves, insects find it particularly appetizing.

The most common diseases are listed below:

1. Botrytis (Gray Mold). Symptoms: the appearance of fuzzy, grayish mold on the leaves and stems. To treat the plant, you must cut away the affected areas and spray the remaining plant with a copper-based or organic fungicide. During the recovery period, do not mist the plant under any circumstances, and reduce watering. To prevent this infection from returning, ensure your room has good air circulation and avoid excessively high humidity with poor ventilation.
2. Root Rot. Symptoms: leaves begin to turn yellow and wilt en masse, and the plant may rapidly decline. Cause: a fungal infection has attacked the roots due to overly soggy soil. It is crucial to act as quickly as possible. Remove the plant from its pot and inspect the root system. If the roots are completely dark, mushy, and foul-smelling, the plant likely cannot be saved. However, if a good portion of the roots is still firm and white, the nematanthus can be rescued. Carefully trim away the rotted roots with sterilized shears, and repot the plant in a fresh, highly aerated mix. Treat the soil with a systemic fungicide. To prevent root rot, always use pots with drainage holes, sterile soil, and never overwater.
3. Powdery Mildew. Symptoms: a white, powdery coating on the stems and foliage. Treatment: if the infection is minor, the coating can be wiped off manually. If it covers a large portion of the leaves, treat the plant with a sulfur-based fungicide or Neem oil. To avoid powdery mildew, regularly ventilate the room where the nematanthus is kept.

Among indoor insects, the following are the most frequent attackers of nematanthus:

Mealybugs. Symptoms: small white, cotton-like masses appear on the leaves, stems, and in the leaf axils. After a few days, the plant begins to wilt. Treatment: manually remove the bugs using a cotton swab dipped in rubbing alcohol, then treat with insecticidal soap.

Spider Mites. Symptoms: fine, delicate webbing appears on the leaves along with light yellow stippling or spots. Treatment: wipe down the leaves and spray the plant thoroughly with Neem oil or a dedicated miticide.

Aphids. Symptoms: new shoots and flower buds become curled, deformed, and dry up. Upon closer inspection, tiny green or black insects can be seen clustered together. Treatment: spray the plant with an insecticidal soap or a permethrin-based indoor plant spray.

Thrips. Symptoms: the nematanthus experiences stunted growth, and the flowers become deformed. Grayish or silvery streaks and tiny black droppings are visible on the leaves. Treatment: apply an appropriate insecticide immediately at the first sign of an infestation.

Propagating Nematanthus

Propagation can be done in two ways.Let's look at each method in more detail.

Growing from Seed

This is a long and tedious process, which is why indoor gardeners rarely use it. Moreover, the results are not guaranteed—out of 5 seeds, 1 or 2 may simply never sprout. To propagate using this method, you must first collect seeds from mature seed pods onto a piece of paper. Prepare a shallow tray with drainage holes and fill it with a mix of peat moss and perlite (or sand). Thoroughly moisten the soil, sprinkle the seeds evenly over the surface, and cover the tray with a clear plastic dome or glass. You should bottom-water the seedlings (by placing the tray in a larger pan of water) and ventilate them daily by lifting the cover. Once the sprouts appear, the cover can be removed entirely.

When the first true leaves appear, the seedlings can be pricked out. Plant 2 to 3 seedlings together in a single small pot, and you can expect your first blooms in about a year.

Stem Cuttings

This is a very easy method with an almost 100% success rate. Freshly cut young shoots can be rooted in sphagnum moss, perlite, or directly in a light potting mix. You can also root them in plain water. Propagation by cuttings can be done year-round. Here are the steps:

Photos Submitted by Our Readers

Add your photo

Show more

+ Click to select a photo

FAQ