How to Grow Stromanthe Triostar Plants (Stromanthe sanguinea)
With colorful leaves that resemble a watercolor painting, the Stromanthe triostar (Stromanthe sanguinea) is a striking addition to any home. Not only are these plants beautiful, but they also put on a show! As members of the prayer plant family (Marantaceae), their leaves move in response to the sun, showcasing pink and green leaves. Before you add a triostar to your home, you should be aware these plants can be a bit finicky. However, they can thrive if you provide the proper care. In this guide, I’m going to take you through everything you need to know about how to grow and care for Stromanthe Triostar at home, including planting considerations, the best soil mix, watering cycles, light requirements, temperature preferences, when to fertilize, pest control, and more!
Stromanthe Triostar Plant Care Essentials:
| Botanical Name: | Stromanthe sanguinea |
| Also Known As: | Stromanthe triostar, magenta triostar, stromanthe tricolor |
| Growing Difficulty: | Moderate, not recommended for beginners |
| Light Requirements: | Bright, indirect light for at least six hours each day |
| Temp & Humidity: | Requires high humidity and temperatures between 65-85ºF |
| Watering Needs: | Aim to keep the soil moist but not saturated, water with distilled water or rainwater when the top inch of soil is dry |
| Soil Preferences: | Well-draining with a pH between 6.0-7.5 |
| Fertilizing: | Fertilize with a balanced houseplant fertilizer once per month in the spring and summer |
| Growth Expectations: | Up to three feet tall indoors |
| Toxicity: | Non-toxic to humans and pets |
Growth Expectations
While stromanthe triostar can grow up to five feet tall outdoors, in my experience, these plants will remain a bit smaller indoors. You can expect your plant to grow up to three feet tall in the ideal indoor environment.
What to Do Before Planting
Since these plants grow upright, you’ll need to find a space that can handle their growth. I find that a side table or plant stand is a great option.
You will also need to select a container with drainage holes. Any material is fine, but be aware that terra cotta pots will cause soil to dry out more quickly.
Best Soil Types
In my experience, the ideal potting mix for these plants will hold moisture yet allow excess water to escape.
I prefer to make my own soil mix at home by combining water-holding materials like peat moss or coco coir with materials that increase drainage and aeration. Here’s my home soil potting recipe which provides excellent drainage, moisture retention, aeration, as well as a stable base for plant growth:
- four parts coco coir
- two park pine bark fines
- one part pumice
- one park perlite
You can also purchase a pre-mixed potting soil. I recommend those that are specifically designed for calatheas (relatives of stromanthe plants).
How to Plant
Planting your stromanthe triostar is easy.
Firstly, I ensure that I select a container with drainage holes. The planter should be just a few inches larger than your plant’s root ball.
I line the bottom of the container with an inch of potting soil then place in my plant’s root ball. I then fill in the remaining space with more potting soil, then water well.
Light Preferences
My plants grow best in locations with plenty of bright, indirect light. I aim to provide them with at least six hours of light per day. They will not grow well in dark areas and become damaged by direct sunlight.
I find that a room with south-facing windows typically receives the best light exposure. Make sure to place your plant a few feet away from the window so it’s not receiving direct light.
If you don’t have a room with south-facing windows, look for a bright spot near a west-facing window.
Temperature and Humidity
Since these plants come from tropical rainforests in Brazil, they like warm and humid air.
I aim to keep the air temperature between 65-85ºF and avoid exposing my plant to both hot and cold drafts. You should also avoid sudden changes in temperature since triostars are sensitive plants.
When it comes to humidity, you can’t have too much of it. Triostars thrive in humidity at or near to 100%. If the humidity is constantly below 60%, your plant will suffer.
Comparatively, the ideal humidity for your home and your health is between 30-60%. That means providing enough humidity is one of the most challenging parts of properly caring for these beautiful plants.
Fortunately, you can alter your home’s humidity. In my experience, a humidifier is the easiest way to keep air moisture high in the area of your home where you keep your plant.
Alternatively, you can mist your plant a few times a day. Another option is to place a tray filled with pebbles and water underneath your plant’s pot. Just make sure the container isn’t sitting in the water.
Watering
Stromanthe triostar plants like their soil consistently moist but not saturated. I aim to water when the top inch of soil is dry, about once every one to two weeks.
Of course, the frequency you water depends on numerous environmental conditions. You will need to water more often in the summer than you will in the winter. Additionally, you’ll want to water more often if your plant is in a bright location and your home’s humidity is low.
When you water, it’s best to avoid tap water. Like all members of the Stromanthe genus, these plants are a bit sensitive to minerals in the water.
Rainwater and distilled water will provide your plants with the moisture they need without causing any harm. I typically leave tap water to stand out over not which allows time for the fluoride content to settle.
Fertilizing
In my experience, regular fertilization will provide stromanthe triostar plants with the nutrients it needs. I select a balanced houseplant fertilizer, and dilute according to product instructions.
Typically, I’ll fertilize once per month during the spring and summer.
Pruning
I find that Stromanthe sanguinea doesn’t require heavy pruning. However, pruning will help it maintain a healthy shape and form.
If you see discolored or diseased leaves, you should remove them. You can do this any time of the year.
I prefer to use a sharp and sanitized knife or pair of scissors to cut the leaf at the end of the petiole.
Propagating
The easiest way to propagate these plants is by division. When you notice your plant has multiple clumps of stems and leaves, it’s ready to divide.
Remove your plant from its container and gently separate the clumps. You may need to use a knife to separate the roots.
After you’ve separated the leaf clumps, place each one in a pot filled with well-draining potting soil then water well.
Repotting
Depending on your plant’s growth rate, I find that I need to repot these plants every two to three years. For me, the easiest way to check is to see roots growing out of the bottom of the container; then I know it’s definitely time to repot the plant. The spring or early summer is the best time for repotting.
To repot, I follow these steps.
- Choose a container that is only one to two inches larger than the original.
- Fill the new container with an inch of well-draining potting soil.
- Remove your plant from the original container and inspect roots for rot.
- Use a sharp pair of shears to trim off any rotten or discolored roots.
- Place the plant in the new container.
- Use more potting soil to fill in the empty space.
- Water well.
Common Problems & How to Treat Them
Dry Leaf Edges
If you notice brown and crispy leaf edges, low humidity is likely to blame. As I mentioned before, these plants LOVE humidity.
To boost the humidity in your home, invest in a humidifier. Not only will this help your triostar, but it will also benefit other humidity-loving houseplants.
While increasing the humidity won’t repair leaves that are already damaged, it will prevent future damage.
Curling Leaves
While it’s natural for this plant’s leaves to move with the day, they shouldn’t curl. Curling leaves can indicate numerous environmental problems.
One possible cause is dry soil. Remember to water your plant when only the top inch of soil is dry. If you notice the soil is dry, a good soak can fix the curling leaves.
Another possible cause is low humidity. Use a humidifier to increase moisture or regularly mist your plant with a spray bottle.
Yellowing Leaves
When your plant’s leaves begin to turn yellow, it’s a sign something is awry.
Overwatering is the most common cause of yellow leaves. Try watering your plant a bit less and see if the problem improves. However, be aware it may take a few weeks or months to see any noticeable improvement.
Another possible cause is poorly draining potting soil. Make sure you are using well-aerated soil and allow excess water to escape.
If the soil still seems moist a few weeks after watering, you should repot your plant using a well-draining soil mix.
One more possible cause is insufficient light. While these plants don’t like direct light, they will suffer in dark places.
Sap-Sucking Pests
Stromanthe triostar is susceptible to damage from sap-sucking pests, including aphids, spider mites, thrips, and mealybugs. These pests can cause stippling and spread disease.
If you spot any of these tiny pests, remove them immediately. You can typically wipe pests off with a soapy rag. However, consider spraying the pests with insecticidal soap or horticultural oil if you’re dealing with a large infestation.
Essential Tools
Since stromanthe triostar likes a humid environment, you’ll need to have a way to boost the humidity in your home.
A humidifier is an easy way to increase the humidity and keep it at a stable level. This inexpensive humidifier (via Amazon) runs quietly and comes with an automatic shutoff. You can control the humidity level, so your triostar stays happy.
About Stromanthe Triostar
The stromanthe triostar (Stromanthe sanguinea) is a member of the prayer plant family, Marantaceae. Therefore, it’s related to plants in the Calathea genus.
Stromanthe sanguinea is native to tropical forests of Brazil and other nearby countries.
People first used these plants as landscaping plants in warm areas. At one point, these plants were named Florida Plant of the Year. Eventually, people began growing triostars as houseplants.
No matter where you grow these plants, you’ll enjoy their beauty. As the name triostar suggests, these plants display three colors: white, pink, and green.
The plant produces thick, elongated, ovular leaves atop short pink petioles. The tops of the leaves are white and dark green with some light pink, with dark pink or burgundy undersides. Each leaf exhibits different color variations, leading to quite a stunning display!
Like prayer plants, the triostar moves its leaves in response to light. The leaves fold up at night and then orient to the sun in the morning.
Due to its beautiful form, Stromanthe sanguinea is primarily used as an ornamental plant. With the proper care, these plants can live over 15 years indoors.
As another bonus, these plants are non-toxic to humans as well as cats and dogs.
Wrapping Up
Now that you know how to care for these tropical beauties, go ahead and add one to your home. Remember to provide your plant with high humidity, moist soil, and lots of bright, indirect light.
Further reading: Discover a collection of amazing plants with pink and green leaves.
Briana holds a B.S. in Plant Sciences from Penn State University. She manages a small market garden where she grows vegetables and herbs. She also enjoys growing flowers and houseplants at home.