Calathea Louisae Care – The Complete Owner’s Manual

Calathea Louisae plants are one of the less common varieties of the intriguing and popular prayer plant, which gets its nickname from its unique leaf movements, which resemble hands lifted in prayer.

Also known as the Calathea Thai Beauty, the Calathea Louisa is an extremely attractive houseplant with vibrant yellow and deep green stripes on one side and a gorgeous purple underside.

Even though this pet-friendly plant grows all over the world today, it originates in the Brazilian rainforest, where temperatures are hot and humidity is high. This is important to know since proper Calathea Louisae care involves replicating these conditions.

Basic Calathea Louisae Care

Let’s get into the essential facts you need to know if you have a Calathea Louisae at home.

Thai Beauties want to live in tropical forests, which means they thrive in environments where temperatures are above 64 ˚F, humidity levels are high, water “rains” down often, indirect sunlight is bountiful, and rich soil provides adequate drainage and nutrients.

When grown outdoors, Calatheas do best in USDA Zones 8 and above, but they can thrive indoors almost anywhere with proper care.

How Much Light Does a Calathea Louisae Plant Need?

In their native environment, Calathea Louisae prayer plants grow under areas shaded by tall trees. However, these places also receive plenty of sunlight—enough to go around for all the tropical plants.

To replicate these conditions, give your Calathea tons of indirect sunlight and some shade. This doesn’t mean all shadeor in a window that receives little to no light.

Never put your Calathea Louisae in direct sunlight near a window—it will burn them!

How to Find Indirect Sunlight for Your Thai Beauty

Find a window (preferably north-facing) that gets a lot of bright direct sunlight. Then choose a place several feet away for your prayer plant. When the sun streams in, your plant’s shadow should look fuzzy. This is indirect sunlight.

If you have a light meter, consider measuring the light levels during the day. Your Calathea Louisae will thrive around 400 FC and survive with 200 FC. Any less than that, and you’re at risk of killing your prayer plant.

Your Calathea Louisae can tolerate up to 2 hours of direct sunlight, but if you can avoid it, you should. Adding a sheer curtain to your windows can be enough to protect your plant from the scorching sun.

Calathea Louisae adapts to the lighting conditions of your home, garden, greenhouse, or wherever you have it. For this reason, I recommend against moving your Thai Beauty around the house often.

The Best Soil Mixture for a Prayer Plant

Prayer plants like soil that drains well but also holds an adequate amount of moisture. The ideal soil pH for a Calathea is 6.5, and you should be careful to avoid soil with high amounts of fluoride (which tends to build up when you water plants with fluorinated tap water).

It can be difficult to strike the perfect soil balance, so I recommend creating this soil blend that provides nutrients:

  • 1 part soil
  • 1 part perlite
  • 1 part compost
  • 2 parts coco peat

You can also create a simpler blend of 3 parts peat and 1 part sand, but you’ll need to fertilize this one.

How to Water a Thai Beauty Prayer Plant

Unlike some houseplants plants that enjoy dry soil, Calathea Louisae prefers slightly moist soil most of the time. If you own a Thai Beauty prayer plant, expect frequent watering.

Calathea Louisae care involves watering your plant every 2-3 days for most of the year.

When your prayer plant is dormant in the winter months, you’ll want to increase the frequency of watering to every other day, about 3-4 times a week. However, you should decrease the amount of water you use.

When watering, avoid using tap water. Calatheas are sensitive to minerals. Instead, I recommend using rainwater or filtered water.

If the soil becomes too dry, your Calathea Louisae will lose color, and the leaves will dry out around the edges, becoming crunchy. Remember, moist soil is best for prayer plants.

Calatheas love humidity and moisture, but they don’t like drowning. Ensure that your Calathea is potted in a planter with plenty of drainage holes that allow the soil to breathe. If your Thai Beauty’s roots sit in stagnant water, it can cause root rot and brown spots on the leaves that signify overwatering.

Humidity Levels for a Calathea Louisae

In the tropical rainforest, Thai Beauties thrive in environments with 90% humidity. At 90% humidity, condensation would build up on the walls of your home—so you probably need to make some adjustments for your prayer plant.

You can wipe your plant’s leaves with a damp cloth, mist it a few times a day, or place a humidifier nearby. Whenever you give your Calathea Louisae humidity in these ways, make sure the water is lukewarm—not too hot and not too cold.

What Temperature is Good for Prayer Plants?

Prayer plants grow best in environments between 65-85˚F, but they prefer warmer temperatures. When small, Calatheas are more tolerant of cooler temperatures, but most mature plants struggle when temperatures fall below 65˚F.

Where Calathea Louisae lives, temperatures are stable. They can tolerate temperature fluctuations only up to 4˚F. So, avoid keeping your plants in areas with poor insulation or drafty windows.

How to Fertilize Your Calathea Louisae

You do not need to fertilize your Thai Beauty prayer plan—but feeding it nutrients will help it grow. These Calatheas can reach sizes up to 30 inches tall with lush 8-inch-long leaves! But remember, too little fertilizer is never a problem. Too much could kill your prayer plant.

If you decide to fertilize your Calathea Louisae, do it primarily during periods of growth and flowering, which occur between March and September.

You may be able to fertilize it as often as every two weeks during this time and every six weeks during autumn and winter. However, if your Calathea is dormant, sick, or damaged, do not fertilize it.

Calathea Louisae enjoys fertilized soil with a 3-1-2 ratio of nitrogen, phosphorus, and potassium (I recommend using fertilizer marketed for turf or fiddle lead ferns). Avoid any fertilizers with a 1-1-1 NPK ratio.

Adjusting Calathea Louisae Fertilizer

You may need more fertilizer if temperatures are hotter or if you water your plant often. Overwatering strips the soil of its nutrients, as the fertilizer runs off with the excess draining liquid.

In contrast, if the weather is cooler or you notice your Calathea is drinking less, you may want to compensate by fertilizing less often.

If your plant’s leaves are turning light green, it means it needs more fertilizer, especially nitrogen, and possibly iron. On the opposite end of the spectrum, overfeeding makes leaves yellow with dead, brown tips.

Growth: What to Expect When Growing a Calathea Louisae

Calathea Louisae can grow leaves up to 8 inches long and 4 inches wide, and they can grow as tall as 30 inches in a home with proper care. Your prayer plant will grow with no fertilizer, but proper care and feeding can result in rapid growth. Most Calathea plants reach a mature height of 1-2 ft within their first year.

How to Propagate a Thai Beauty

If your Calathea is growing healthily with frequent watering, high humidity, and protection from direct sunlight, then you can propagate it.

To propagate a mature Calathea, you’ll need to divide the one plant you have into two. Large Calathea Louisae will spread in their pots and develop new clumps on their sides. These clumps can be removed and grow independently.

For about three days before you plan to propagate, water your Calathea well. Then, separate the roots gently. You may also need to use a clean knife or scissors to divide your Thai Beauty. Both sides must have a clump of the root system and leaves attached to the stem.

Repotting Your Calathea

You should repot your Calathea Louisae once a year, every spring until your plant is at least four years old. Then, you can repot once every two years.

Signs that your Calathea needs repotting include overgrown or extremely dense roots, yellow or wilted leaves, and slowed growth. And if your Calathea falls over or is top-heavy, it needs a larger pot.

I also recommend always keeping your Calathea (and any other plant) in porous materials like terra cotta. This promotes proper drainage and plant health.

Pruning Your Calathea

You do not need to prune your Calathea Louisae, but regular pruning will promote flowering. And if you suspect that your plant is sick or diseased, pruning infected leaves could save your plant’s life.

Plant Toxicity: Are Calathea Louisae Prayer Plants Safe?

Calathea, including the Calathea Louisae, are entirely pet-friendly. Safe for cats, dogs, and anything (or anyone) else who might touch or consume your plants, the Thai Beauty prayer plant is perfect for homes with pets and children.

Common Calathea Louisae Pests, Diseases & Issues

Whenever any of your plants have a problem like a disease or a pest infestation, you should always start by quarantining your plant.

Calathea Louisae prayer plants are especially susceptible to fungal diseases. If your Thai Beauty suffers from fungus or root rot, you’ll need to administer a fungicide and repot. And be careful not to overwater!

The most common pest problems you might encounter when caring for a prayer plant are spider mites, fungal mosquitoes, and scale. For all these pests, neem oil works as an effective, safe, and natural insecticide.

For a quick fix, you can also attempt to remove pests by hand, dispose of heavily infested leaves, or spray bugs with a soapy water mixture to trap and drown them before wiping them away.

Q. Can Calathea Louisae Tolerate Low Light Conditions?

Calathea Louisae prefers bright indirect sunlight and some shade—which means they can tolerate low light conditions better than most houseplants. Although you can grow Calathea in low light conditions, they are unlikely to thrive.

Providing the proper lighting conditions and Calathea Louisae care is the best way to ensure your plant stays healthy.

Q. Where Can I Plant a Calathea Louisae?

Calathea Louisae makes an excellent houseplant. Thai Beauty prayer plants are also well known as ornamental plants in various landscaping projects, tropical gardens, and Balinese gardens. With colorful leaves, this prayer plant’s unique aesthetic lends a special touch of decorative greenery to any space—as long as it receives the proper care.

Q. Do Calathea Louisae Have Flowers?

When grown in their native habitat, Calathea plants do flower. They tend to produce small, delicate, white flowers—but don’t expect to see one in person. It is somewhat rare to see a flowering Calathea Louisae grown indoors—or even one grown outdoors outside of the tropical rainforest.

In order for your Calathea to flower, it needs perfect conditions, including enough light, adequate food, and more.

Q. Can I use Leaf Shine Products on my Calathea Louisae?

You should never use leaf shine products on Calathea Louisae. Leaf shine products can clog important pores on the surface of your Thai Beauty’s leaves. These pores help your plant “breathe.” When clogged, they can appear unattractive and blemished—and clogged pores can be harmful to your plant’s overall health.

Instead, I recommend rinsing any dust off with cool water and gently toweling it dry. Moving your plants into the shower for regular dust cleaning is the easiest and best method to shine leaves.

photo of Charlotte Bailey founder of Oh So Garden

Author

Charlotte Bailey

Charlotte is a Qualified Royal Horticultural Society Horticulturist, plant conservationist, and founder of Oh So Garden. Armed with a background in Plant Science (BSc Hons, MSc) and 5 years of hands-on experience in the field, her in-depth guides are read by over 100,000 people every month.

For her work, she's been awarded the title of Yale Young Global Scholar, and been featured as a garden and houseplant expert across major networks and national publications such as Homes and Garden, Best Life, Gardeningetc, Today.com, BHG, Real Homes, and Country Living. You can find her on Linkedin.

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