Nematanthus Gregarius Care – Goldfish Plant Growing Guide

Last Updated on April 15, 2022 by Admin

The Nematanthus Gregarius is better known as the goldfish plant. This is due to its bright red-orange flowers that look like the popular sea creature.

Note that there are about 25 Nematanthus varieties. And they have a bright colored flowers which vary in some way from one another. Thus, all of them are commonly called goldfish plant.

That said, the Nematanthus Gregarius is sometimes called the clog plant or the guppy plant as well.

Therefore, when you see any of these names on the store labels, they refer to the same plant.

The Nematanthus Gregarius can grow to about 1.5 feet high and 3.3 feet long to the sides. Its long stems will extend outwards and are filled with dark green leaves.

The plant is native to the tropical regions of South America including Brazil and Costa Rica.

How do your care for Nematanthus Gregarius? The goldfish plant needs bright, indirect light if you want it to produce its gorgeous clusters of flowers in July and August.

The plant can be grown in a pot or hanging basket thanks to its long vines. Keep it in a warm spot with good humidity. Don’t overwater the plant and use well-draining soil.

Goldfish Plant Plant Care

Nematanthus Gregarius Light Requirements

The Goldfish Plant grows best in bright, indirect light. It will likewise be happy with medium light.

Good lighting is very important not only for the health and growth of the plant but also if you want it to bloom.

After all, most home gardeners will get the Goldfish Plant because of its beautiful bright orange flowers.

Therefore, make sure you give it enough light to bloom.

That said, there’s good new and bad news.

The good news is that the Goldfish Plant grows well indoors. And unlike many other plants that struggle to produce flowers indoors due to the lower light compared to outdoors, the Goldfish Plant blooms quite well indoors.

The bad news is that you want to keep it away from direct sunlight.

Any strong, harsh or very intense light is just too much for it to handle for more than 2 hours or so per day.

Therefore, try to avoid the afternoon sun as overexposure to this will eventually burn its leaves.

This means it is a good idea to distance the plant at least 2 or 3 feet away from the west and south facing windows. There directions are where the afternoon sun comes from.

The goal is to keep the plant away from the sun’s rays during this time.

However, if you’d like to keep the plant right by the west or south facing windows, another option is to filter the light.

You can use a shade cloth or set up sheer curtains or blinds to block out some (but not all) of the sun.

On the other hand, the Goldfish Plant will appreciate morning sun.

It will grow best if you give it a good amount of direct morning sun from an east facing window. That’s because the early morning sun (before 10:30 a.m.) is gentle.

So, to summarize, avoid low light if you want your Goldfish Plant to produce flowers. Also, keep it away from very strong light.

Outdoors, partial shade is best.


Nematanthus Gregarius Temperature

The Nematanthus Gregarius is a warm weather loving plant. It prefers temperatures from 60 to 80 degrees Fahrenheit.

This is the environment it is happiest with and will grow best in.

That’s because it is native to the tropical rainforests of South America. As such, it is used to warm to hot weather

However, it favors a more moderate to warm climate because it lives under the canopy of the large trees and plants in the wild.

Therefore, it does not bear the brunt of the sun’s rays nor the heat that’s emitted from this.

This makes the Nematanthus Gregarius easy to care for indoors in homes and offices.

At the same time, it is important to note that it cannot tolerate the cold. It has a difficult time with temperatures below 50 degrees Fahrenheit.

And while it can stay in sub 50-degree Fahrenheit for very short periods of time, you don’t want to leave it there for long as it will eventually struggle, experience damage, drop leaves and die.

This means you also want to keep it away from air conditioners and open windows where cold drafts can enter.

Needless to say, keep it indoors during the colder months of the year if you live in areas with snow and freezing conditions during winter.


Guppy Plant Humidity

The Goldfish Plant prefers moderate to high humidity. But it does well in average room humidity which makes it easy to grow.

As long as you maintain indoor humidity of 25% to 50% you should not have any problems.

Most homes have humidity running between 20% to 50% which means that not only is its temperature ideal for indoor growing but so is its humidity preference.

As such the Goldfish Plant is much easier to deal with as far as humidity goes compared to many other tropical plants that come from the South American rainforests which prefer 50% to 70% most of the time.

That said, if you can give your Goldfish Plant higher humidity, it will be happier.




How Often to Water Goldfish Plant

Watering is a very important part of caring for the Nematanthus Gregarius. That’s because it likes moist soil but is prone to overwatering.

Additionally, it can only tolerate short periods of dryness. Therefore, avoid letting the soil stay completely dry for too long.

This means that balance is essential.

And you want to stay away from the extremes.

To avoid overwatering, allow the top 2-3 inches of soil dry between watering. The easiest way to gauge this is stick your finger into the soil and check for moisture.

Insert your index finger down up to around the second knuckle or so. This is about 2 inches from the surface of the soil.

If the soil at that depth is dry, you’ll know as all you’ll see in your fingertip is soil dust.

But if it feels moist, wet or soil sticks to your fingertip, then don’t water yet. Instead, wait a few days then test the soil again.

Only water when the soil has dried at least until the top 2-3 inches.

On the other hand, avoid letting the soil go completely dry. Try to water the plant before this happens.

Also, always check the leaves to see what the plant is telling you.

Yellow leaves that are soft and limp is usually a sign of overwatering. Although, when the roots start rotting, you’ll also see brown leaves as well as dropping leaves.

With underwatering, the plant will look sad, it will droop and wilt.

The leaves will turn brown, and they will feel dry and crispy instead of soft and limp.

Finally, if you water from above, don’t water over the leaves and get them all wet. Instead, water directly on the soil.

You can direct the hose onto the rim of the pot and let it run on a low stream. Or you can use a watering can with a long, narrow neck that will make it easy to reach the soil despite of the leaves.

Wetting the leaves too much will increase the risk of fungal infections.


Goldfish Plant Potting Soil

The best soil for the  Nematanthus Gregarius is a porous, well-draining mix that’s rich in organic matter.

Here, the simplest solution is to use African Violet potting soil.

Most nurseries and plant stores will carry this as this soil is one of the basic kinds.

If you buy it commercially, you can just open the bag and follow the instructions.

On the other hand, if you prefer to make your own potting mix at home, you can use a combination of potting soil, peat and perlite.

Together, they will allow the soil to hold onto water to keep the soil moist. But the perlite will ensure that it has good enough drainage so the roots don’t end up sitting in water.

This way, you avoid leaving the roots in water which results in overwatering and possibly root rot.

Also, don’t forget to use a pot with drainage holes at the bottom.

The holes will allow excess liquid to drip out instead of accumulating at the bottom of the pot.


Nematanthus Gregarius Fertilizer

Give your Nematanthus Gregarius fertilizer regularly if you want it to bloom. However, make sure you read the instructions in the product label.

And avoid over fertilizing the plant.

Excess fertilizer will damage not only the leaves but also the roots because they contain salt which is toxic to the plant if too much builds up in the soil.

A high quality balanced liquid fertilizer works well. Make sure that it not only has macronutrients but also include micronutrients.

Apply once every 2-4 weeks during the spring and summer which is when the plant is actively growing.

It does not need to be fed during the winter. Although you can do so once every 2 months if you wish.

If you don’t have the time to regularly fee the plant, you can opt for a slow-release fertilizer. This reduces the number of times you’ll need to apply.

Note that slow-release fertilizers come in pellet form. So, make sure you know how to distribute them for maximum effectivity.


Nematanthus Gregarius Pruning

The Goldfish Plant will grow to about 3 feet long. It does well in pot or in a hanging basket. So, you have the option to put it where you feel it looks better.

Depending on where and how you want it to look, you may or may not need to prune it regularly.

That said, then its long stems start going wayward, you can trim them to keep the plant looking neat.

In most cases, you’ll want to prune the plant more when it is young. This will help it produce more shoots and leaves giving you a bushier plant.

A pro tip you can use is to cut the flowers when they are beginning to wilt. This will encourage it to bloom more.

Don’t forget to clean the plant as dust can collect on its leaves.

Because it has lot of leaves, the best way to clean its leaves is to rinse it with water. You can use a sink or the shower head in the bathtub to give the plant a little cleaning every so often.

Make sure to let it dry and drain after to avoid overwatering.


How to Propagate Goldfish Plant

The Goldfish Plant can be propagated from stem cuttings.

Since it grows a lot of long stems, you can take stem tip cuttings or take entire stems and cut them into sections and grow each of those into new plants.

You can also group a few stem cuttings together so you can have a bushier plant that will look good in a pot sooner.

The best time to propagate the Goldfish Plant is during spring.

To propagate, take a few stem cuttings. Make sure the stems you choose don’t have flowers. You also want each cutting to be between 2 to 5 inches long.

Once you have the cuttings, you can apply rooting hormone on the cut end.

The plant the cuttings into a pot with well-draining potting mix.

Keep the pot in a well-lit area with no direct light. Water the soil as it gets dry but avoid overwatering.

In a few weeks the cuttings will develop enough roots to establish itself onto the soil.


How to Repot or Transplant Goldfish Plant

The Nematanthus Gregarius does not require frequent repotting. And don’t repot it unnecessarily as this can interrupt its growth. It can even cause stress and shock.

Instead, it takes about 2 to 3 years before the plant needs repotting.

It also enjoys being rootbound. Therefore, there’s no hurry to do so and you can leave it there for a little while longer when this happens.

However, after a while, you’ll need to repot it to prevent the roots from getting too overcrowded.

When you do, choose a container that is 2 inches wider than the current one it has. Make sure that the new one has drainage holes at the bottom. This will allow excess moisture to exit the container.

Also, replace the potting mix with a fresh one.


Is It Toxic/Poisonous to Humans, Cats & Dogs

The Nematanthus Gregarius is non-toxic to people and animals. Therefore, it is safe to keep in your home with young children, cats and dogs.

Note that the deep green colors and bright flowers are quite attractive to young kids and pets.

Thus, they can end up playing with the plant or even nibble away at some of its leaves and blooms. While non-toxic, you still want to guard against this as the plant is not edible.


Goldfish Plant Problems & Troubleshooting

Guppy Plant Pests

Regular pest inspection is one of the more challenging things to do with the Nematanthus Gregarius.

This is not because it gets a lot of pests which it does not.

Although, it can still experience the common houseplant pests including mealybugs, aphids, spider mites and scale.

Instead, it is the number of leaves and their small size that makes it such a hassle.

Since the bugs like to hide behind the leaves and the nooks can crannies in the stems, you need to be quite thorough considering how many stems and leaves there are.

That said, it is something you need to do.

Otherwise, once these insects get to your Nematanthus Gregarius, they will grow in number quickly and keep feeding on its sap.



Root rot is the biggest thing to watch out for. Since excessive watering is usually the cause, you want to be careful with when and how you water the plant.

Additionally, fungal leaf infections are another problem that the Nematanthus Gregarius is prone to. Again, this is due to excess moisture.

Therefore, be mindful of watering and keep the plant in a well-lit location with good air circulation.

This will dry any droplets or water faster.

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