Contributed By: Martha Plousos
I first saw a Nematanthus gregarius, also known as the goldfish plant, in person, about 7 years ago at a Home Depot. This may sound surprising considering I’ve been growing houseplants for over two decades, but it’s true. I had seen pictures of the plant in some books I own, but it never really registered as interesting or very appealing. The pictures don’t do the plant much justice; it’s much more fascinating and attractive when you see it in person. And when I did finally see one up close, I couldn’t resist its charm. It was a tiny little specimen in a 2” hanging basket, the cutest thing I’d ever seen. So I took it home. And much to my surprise, it quadrupled in size the first year and showered me with flowers for nine straight months.
Originating from the tropical forests of Brazil, this lovely plant is just one of over 30 species of Nematathus, all of which produce flowers in varying shades of reds, yellows and oranges. Nematanthus gregarius belongs to the Gesneriad family, which consists of over 2,500 species of plants. Included in this large and diverse family are common favourites such as Episcia (Flame Violet), Sinningia speciosa (Florist Gloxinia), Streptocarpus (Cape Primrose), Achimenes (Cupid’s Bower), Aeschynanthus (Lipstick Plant) and the best-known member of all: Saintpaulia (African Violet).
When goldfish plants are young, the stems grow upright. As they age, they tend to trail; this makes them a wonderful choice for hanging baskets. The tough, branching stems bear bright green, glossy leaves that are succulent and waxy. The foliage, which is small and oval in shape, grows to about ¾ to 1 ½ inches long. The plant produces orange, pitcher-like flowers on and off year round, but mostly during the warmer seasons. If given proper care, older plants can flower permanently for years. Really young plants may need to mature to about a year old before they begin to bloom.
Although I personally find this plant extremely easy to grow, I have run across houseplant growers – from novices to experts – who will tell you differently. I believe that the main complaint is the lack of blooms, which can be caused by improper care. Goldfish plants do not have many demands, and they do put up fairly well with slapdash care, but if you want to see any flowers, you will need to fulfill some of their needs.
Perhaps the most important requirement in keeping this plant in top shape, which in turn will encourage it to bloom, is adequate light. The Nematanthus gregarius needs a very brightly lit location. Place it where it can receive some direct or filtered sun; this will depend on which direction you choose to grow it in. Early morning eastern or late afternoon western direct sunshine can be handled very well; filter it with a sheer curtain if your plant shows signs that it is receiving too much light. Generally speaking, these locations are rarely a problem. A southern location that offers curtain-filtered sunshine is also a good choice; always make sure that your plant is protected from the hot, midday summer sun. During the cooler months, you can allow your plant to enjoy a few hours of direct sunshine in east or west locations, and a couple of hours in the southern ones (southeast, southwest). In any case, monitor your plant for signs of contentment or discontentment and adjust the light accordingly. If your plant is not flowering, it may need to be moved to a sunnier spot.
Goldfish plants have small root systems and are quite susceptible to rot. To avoid this problem, use a fast-draining, porous medium that will not stay soggy. Water regularly during the growing season and keep the medium evenly moist. Allow the plant to dry out slightly before watering again, but never allow it to dry out completely. If you do forget to water this plant and the soil dries completely, you will discover that Nematanthus gregarius is quite tolerant of drought and can go for a surprisingly long period without water (the succulent leaves help). But don’t take the plant’s tolerant nature for granted; there will come a time when your goldfish plant will not bounce back after one too many experiences with severe under-watering, so don’t make it a habit. During the cooler months, water more sparingly. You can switch to hydroculture; Goldfish plants are wonderful candidates. Take cuttings, root them in water and pot them up in clay pellets. Or rinse the roots free of soil and pot the plant in the clay medium. Both ways work.
As a tolerant plant, Nematanthus gregarius will put up with dry air. But it won’t be happy with it. In very low humidity, the plant will most likely not flower, and if it does produce a few blooms, they’ll probably drop prematurely, usually without even opening. In addition, dry air will invite pest infestations, particularly attacks from the insufferable spider mite, so increase the humidity if it’s too low. There are many ways to do this: pebble trays, double potting, grouping, humidifiers.
Average indoor temperatures are fine. The plant can tolerate levels down to 5°C (41°F) and survive, although I wouldn’t really recommend long-term exposure to such low temperatures. During the active growing season, feed regularly (about every two to three weeks) with any standard houseplant fertilizer at half recommended strength. Do not feed during the fall and winter.
When the colder months arrive, you may find that your plant has lost some of its luster and all of its flowers. Don’t despair. Your plant is trying to relay that it is in need of a resting period. You can continue to grow your plant as mentioned above, or you can assist in your plant’s preferred winter state: dormancy. If you wish to support your plant’s desire to take a snooze, place it in an area where temperatures are slightly cooler and light levels are slightly decreased (bright but not sunny). This extra nurturing is commendable but not absolutely necessary. I have never moved my plant to a cooler, shadier location, and it hasn’t seemed to care. It does stop flowering and growing new leaves during its rest period, but eventually it starts to put out new growth and produce an abundance of lovely blooms.
After your plant has finished flowering, you can cut it back to encourage branching and compact growth; regular pruning is essential if you want a full and bushy plant. Occasional pinching will also encourage the stems to branch; make sure you do not pinch where flowers are developing. Root the cuttings to create new plants. Repot overcrowded plants in a larger container, or divide them and pot them up in separate containers; this will increase your quantity of goldfish plants easily.
Nematanthus Gregarius, in my opinion is one of the easiest flowering plants you can grow indoors. Even when it’s not in bloom, this plant’s glossy foliage makes it an attractive specimen worthy of a bright spot in your home. With proper watering, adequate light, sufficient humidity and regular feeding during the growing season, you will be rewarded with beautiful foliage and flowers for many years to come.