The Calathea Grey Star is also known by many other names including:
- Calathea Setosa Grey Star
- Calathea Gray Star
- Grey Star Plant
- Ctenanthe Grey Star
- Ctenanthe Setosa Grey Star
Of course, as always some people will spell it “grey” while others will spell it “gray”.
But more importantly are the two final names on the list. These are the Ctenanthe Grey Star and the Ctenanthe Setosa Grey Star.
The reasons these are valuable is that the Calathea Grey Star is not a true Calathea, instead it is a Ctenanthe, which is a very close relative of the Calathea.
Therefore, you’ll notice that care for the plant is somewhat similar to the Calathea but also different in other ways. The most evident is that the Ctenanthe Grey Star can be propagated via stem cuttings. This is something you cannot do with calathea plants.
In any case, I’ll discuss more of that below in the Propagation section.
That said, the Calathea Grey Star is native to Central and South America. And it is best know for its stunningly unique foliage.
Its leaves are big and thick. They also have a unique aesthetic thanks to their silver-gray stiped patterns that cover the dark green color underneath.
Also, the dark burgundy-purple undersides are a perfect contrast to the top side of its foliage.
This makes them striking houseplants.
Calathea Grey Star Plant Care
Choose a location with bright, indirect light for your Calathea Grey Star. This is its ideal spot indoors as it will thrive in a well-lit location. It also prefers natural light. Although if you can’t get enough sunshine, you can use grow lights as well with no problems.
However, avoid areas that are too bright or sunny as this can cause its leaf color to fade. This is true with artificial lighting as well. As such, make sure that the plant is about 8 to 12 inches from the bulbs.
In general, keep the plant away from direct sunlight. The only exception to this is early in the morning and late in the afternoons as the sun is gentle during these times.
The Calathea Grey Star cannot tolerate mid-day direct sunlight as this is too intense for it.
The Calathea Grey Star prefers room temperature that is consistently kept between 65 and 80 degrees Fahrenheit. The plant is accustomed to moderate to warm weather because it hails from the tropical rainforests of Central and South America.
As such, it is used to warmer climates.
That said, although it has less issues tolerating hotter weather above the range, it is a good idea to keep it away from 90 degree temperature and higher. The farther away you get above the range the slower its growth will get.
And if the Calathea Grey Star is left in very hot environments for long periods of time, it will experience heat stress.
On the other hand, the more concerning thing to watch out for is the cold. The plant does not tolerate the cold well. And it does not do well under 60 degrees Fahrenheit.
This is why it enjoys USDA Hardiness Zones 9 to 12 best if kept outdoors. The weather stays moderately warm all year round with sunshine and no snow.
High humidity is best for the Calathea Grey Star. In fact, it enjoys 70% humidity or higher most. This makes it a bit harder to care for indoors compared to other houseplants, unless you live in a tropical region or have a greenhouse.
That said, it can tolerate slightly lower humidity at around 50% to 60%. Nevertheless, in most cases, it will probably need regular misting or a humidifier to keep it healthy and happy.
You can likewise use a pebble tray if you don’t want to keep misting or invest in a humidifier.
Its preference for high humidity also means that you need to be careful with certain appliances like air conditioners and heaters. These dry the air significantly each time you use them.
Therefore, it is a good idea to keep the plant in a separate room.
How Often to Water Calathea Grey Star
The Calathea Grey Star is quite fussy when it comes to watering. Therefore, this is something you want to pay extra attention to especially early on.
Once you get the hang of watering the plant and can maintain good humidity, the rest will be easy.
What makes watering the Calathea Grey Star tricky is that it enjoys moist soil but cannot tolerate overwatering.
This means the best way to water the plant is allow the soil to dry a bit between waterings.
Then after the top soil is dry at least 1-2 inches, water thoroughly.
If you want to water from above, this means soaking the root ball so the roots get drenched. This allows them to get the water they want.
But make sure to start draining the excess moisture after the root ball gets saturated. This way, the soil is moist and the roots stay hydrated while the soil isn’t waterlogged.
Too much water puts the plant at risk of root rot. It also increases the risk for fungal infections.
That said, the plant also does not like going dry. When this happens, you’ll see its leaves curl. This is a sign that it is very dry and need water.
Therefore, the easiest way to gauge how often to water the plant is to stick your finger into the soil up to about 2 inches from the surface. If the soil at that depth is completely dry, you can water.
Avoid doing so before then.
By doing this, you’re able to avoid overwatering and underwatering.
Based on this method, you’ll lightly find yourself watering the plant about once to twice a week during summer, depending on how hot the weather gets.
In the cold of winter, this will also allow you to automatically cut back on watering frequency.
Calathea Grey Star Potting Soil
Since the Calathea Grey Star is sensitive to too much moisture, it is important to use well-draining potting mix. This gives you the right balance of moisture retention and drainage.
And in doing so, it allows the roots to stay hydrated but not leaving them sitting in water for prolonged periods of time.
If you prefer using a commercial blend, you can opt with African Violet mix. I’ve heard some growers use Cactus mix as well although I’ve never tried it. So, I can’t say how well it works.
For me, I prefer making my own DIY Potting mix for Calathea Grey Star. This comes out cheaper. And you can adjust the components and amounts depending on how the plant responds.
Here are a couple of simple potting mix recipes that work well for the Calathea Grey Star.
- 50% peat (you can use coco coir instead as well)
- 40% perlite
- 10% compost
Another option is to use:
- 30% coconut coir
- 25% perlite
- 25% orchid bark
- 10% worm castings
- 5% charcoal
This requires a bit more ingredients and measuring. But it also is more optimized for the plant.
The Calathea Grey Star produces large, beautiful foliage. As such, it will need enough nutrients to keep this up. Therefore, it is a good idea to regularly feed the plant.
That said, it is not a heavy feeder. Therefore, use a weak fertilizer or dilute the dose to half or quarter strength.
You can use a liquid houseplant fertilizer to make it easier to do this. Just add more distilled water.
Only feed the plant during its growing season (spring and summer). Its growth tends to slow and stop once the cold arrives, so you can stop feeding it by early or mid fall.
The Calathea Grey Star can grow to about 3 feet tall or so with proper care. It leaves will grow upwards and bend out towards the sides.
This makes it beautiful to look at. It also make pruning a low maintenance task at least early on.
As the plant gets bigger, you’ll see larger leaves the bend outward more. This will cause the plant to take up more space.
So, depending on whether you like the look and have enough extra room to the sides of the plant, you may or may not want to prune it.
Pruning is more for aesthetics in this case. You can also use it to shape the plant and prevent it from getting too tall or bushy.
The only necessary pruning needed is removing damaged, yellow or discolored foliage.
It is also a good ideal to clean the leaves with a damp cloth every so often.
How to Propagate Calathea Grey Star
The most common ways to propagate the Calathea Grey Star is by stem cuttings and division.
Note that Calatheas in general cannot be propagated from stem cuttings, so what gives?
The reason you can propagate the Calathea Grey Star using stem cutting is that it is not a true Calathea. Instead, it is a Ctenanthe which is closely related to the Calathea.
So, technically the plant is a Ctenanthe Grey Star.
This is why it propagates well from stem cuttings. Of course, you can likewise divide the plant to propagate it.
That said, the simplicity of stem cuttings, and the ability to keep the parent plant intact while you grow multiple new plants is more enticing as well.
To propagate the Calathea Grey Star from stem cuttings:
- Take a healthy stem. Make sure to cut below the node. A stem cutting without a node will never root. So, make sure each cutting you get has at least 1-2 notes.
- This is likewise important when buying cuttings online or from someone else Some scammers will give you stems with no nodes. These are completely useless for propagation purposes.
- Anyways, doing back to propagation.
- Once you have the cutting, prepare a small pot and fill it with well draining soil.
- Dip the cut end of the stem cutting in rooting hormone.
- Then plant the cutting into the potting mix. Make sure the nodes are buried under the soil And remove any leaves that end up in the soil.
- It takes about a month to 6 weeks for the cutting to root.
You can likewise propagate the cutting in water.
- Here, place the cutting in a glass container filled with water instead of a pot with soil mix.
- Submerge the nodes under the water line
- And keep the plant in a well-lit location with no direct sunlight. Ideally keep it in moderate to warm conditions with good humidity as well.
- The advantage of rooting in water is that you can see the roots as they start to grow.
- Once the roots are long enough (at least 2-4 inches), you can move the cutting from water into a pot with soil mix.
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How to Repot or Transplant Calathea Grey Star
The Calathea Grey Star will need to be repot every 1-2 years.
Since it does not like being moved, try to leave it alone after you’ve found a good spot for it.
Once roots start coming out from the drainage holes at the bottom of the pot or the soil begins to get loose, it is time to repot.
Wait until the spring to do so. This is the best time to propagate the plant as it will recover faster and grow quickly after.
Is It Toxic/Poisonous to Humans, Cats & Dogs
The plant is non-toxic to pets and humans. This makes it pet- and kid-friendly for families with either or both. That said, the Calathea Grey Star is not edible. Therefore, you still want to keep an eye out for the kids, cats and dogs when they try eating the plant.
While not poisonous, chewing or consuming its leaves or stems can still cause side effects.
Problems & Troubleshooting
The Calathea Grey Star can be prone to spider mites and other insects that like to suck on sap. This includes aphids, mealybugs and scale.
Since stealing the sap of the plant results in loss of moisture and nutrients, it can turn the leaves yellow or brown and even stunt the growth of your plant.
Therefore, make sure to immediately treat the plant once you see any signs of these insects.
Overwatering is the plant’s #1 enemy. Too much moisture not only increases the risk of root rot but also makes it susceptible to bacterial and fungal infections.
Thus, diseases can damage the roots, stems and leaves.
The best way to avoid this is to keep an eye out for excess moisture. This is true when watering the soil, wetting the leaves or even misting the plant.