Goldfish plant care

Goldfish plant care comes down to bright, filtered light, a loose mix kept lightly moist (water when the top 1/2 inch dries, never soggy), soft room-temperature water, 65-75°F and around 50% humidity. Flowers form on new growth, so pinching young tips and cutting back leggy stems after blooming keeps the plant full of its orange "goldfish." The ASPCA lists it as non-toxic to cats and dogs.

What a goldfish plant is

The goldfish plant most often sold in the US is Nematanthus gregarius (formerly Hypocyrta, also sold as N. radicans), a trailing evergreen from tropical South America in the gesneriad family, the same family as African violets. The RHS describes it as a trailing sub-shrub with fleshy, glossy dark green leaves and clusters of up to three pouched, tubular orange flowers about an inch long in summer, growing 4-20 inches tall and spreading up to 3 feet. It holds the RHS Award of Garden Merit as a houseplant.

The Gesneriad Society lists goldfish plant (Nematanthus) among the most commonly grown gesneriads, alongside African violet, lipstick plant and florist gloxinia. If you've grown an African violet, the same basic rules apply: bright filtered light, soft water and a light, airy mix.

Look-alike: lipstick plant (Aeschynanthus) has larger leaves and red tubular flowers emerging from dark calyxes like lipstick from a tube; it's also a gesneriad with similar care.

Light

The RHS recommends bright, filtered light. The Gesneriad Society says gesneriads need good, bright light for healthy plants and abundant flowers; some tolerate a moderately sunny window if it doesn't get too hot, otherwise shade with a curtain or move them back.

The light-shelf numbers come from the Gesneriad Society's culture guide, which notes most gesneriads grow and bloom very well under artificial light; see grow lights.

Watering

Goldfish plants are epiphytes in nature, growing on trees, so the roots want moisture and air at the same time. Keep the mix lightly moist, let the top 1/2 inch dry, then water thoroughly and empty the saucer. The RHS specifically recommends soft water; filtered water or rainwater works, and avoid water run through a salt-based softener.

Use room-temperature water and keep it off the leaves; like other gesneriads, cold water on foliage can leave spots. Overwatering in a dense mix leads to yellow leaves and root rot; letting it dry out completely leads to wilting and leaf drop. More in our watering guide.

Humidity and temperature

The Gesneriad Society suggests about 50% humidity, noting many gesneriads bloom better with more. In a heated US home in winter, humidity often drops below 30%, so set the pot on a tray of damp pebbles, group plants, or run a small humidifier nearby. See humidity.

Keep it at 65-75°F. Goldfish plants dislike cold: a chilly windowpane, a drafty door or cold water in winter are the classic triggers for sudden leaf drop. Keep it above 60°F and away from AC vents and heat registers.

Soil and repotting

The Gesneriad Society recommends a loose, porous mix that holds moisture yet drains well: any prepared African violet mix with some perlite added. A mix of two parts African violet or indoor potting mix to one part perlite works well.

Repot only when the rootball is tight and overgrown, moving up one pot size, in spring. Goldfish plants have fine roots and do well in relatively small, shallow pots or hanging baskets with drainage. See repotting.

Fertilizer

The Gesneriad Society recommends constant feeding for gesneriads: a balanced 20-20-20 or bloom-type 15-30-15 fertilizer at one-tenth to one-quarter label strength at every watering, with plain water once a month to flush salts. If you prefer monthly feeding, use half strength from spring through early fall and stop in winter. White crust on the pot rim or brown leaf edges means salts are building up. More in fertilizer.

Pinching, pruning and getting more flowers

The RHS advises removing shoot tips on young plants to encourage branching. Because flowers form on new growth, pruning is also the main bloom tool.

1. On young plants, pinch the tip of each stem once it has 4-5 leaf pairs.
2. After a flush of flowers, cut long stems back by a third to a half, just above a leaf pair.
3. Remove bare, woody stems entirely to make room for new shoots.
4. Feed lightly and keep it in bright filtered light so the new growth blooms.
5. Avoid heavy pruning in winter when growth is slow.

Common reasons it won't flower: too little light, no fresh growth, a long cold spell or heavy salt buildup. See not blooming and leggy plants.

Propagation

The RHS recommends softwood (stem-tip) cuttings in spring. The Gesneriad Society's propagation guide adds that stem cuttings root very easily: use a piece with at least three leaf nodes, strip the lower leaves, insert it in moist mix and enclose it to keep humidity high; rooting hormone isn't usually needed.

1. Cut 3-4 inch tips with at least three leaf nodes.
2. Strip the bottom leaf pairs.
3. Insert 3-5 cuttings in a small pot of moist, light mix with perlite.
4. Cover with a clear bag or dome, in bright indirect light at 70-75°F.
5. Some root in days, others in a few weeks; when they resist a gentle tug, gradually remove the cover.

Pruning leftovers make good cuttings; pot several together for a bushy plant. See propagation.

Why goldfish plant drops leaves

Leaf drop is the most common complaint, and it nearly always traces back to temperature or water rather than disease.

Once the cause is fixed, new leaves usually appear along pruned stems within a few weeks in spring and summer, more slowly in winter. See dropping leaves.

Normal or a problem?

Pests

The RHS lists aphids, particularly on young growth, and notes goldfish plants are generally disease-free. Indoors, also watch for mealybugs in leaf joints and spider mites in dry winter air. Rinse aphids off or use insecticidal soap according to the label; dab mealybugs with rubbing alcohol. See aphids.

After you bring one home

1. Unwrap it right away; goldfish plants drop leaves if chilled in transit in winter.
2. Place it in bright, filtered light away from cold windows and drafts.
3. Check the mix: if it's light and dry, water with room-temperature soft water.
4. Inspect stem tips for aphids before setting it near other plants.
5. Hold off on repotting until spring and only if the roots are crowded.

Toxicity

The ASPCA lists goldfish plant (Hypocyrta, also called candy corn plant) as non-toxic to dogs and cats, which makes it a good flowering choice for homes with pets; see pet-safe plants and flowering houseplants. If a pet eats a lot of any plant and seems unwell, call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435; for children, Poison Control at 1-800-222-1222.