Rex begonias are the drama queens of the plant world, but with the right care, they’ll reward you with stunning foliage. Learn how to keep your rex begonias thriving with this comprehensive guide.
Rex begonias are one of the prettiest houseplants to grow but can be a little finicky if you don’t give them what they want to thrive With their vibrant, patterned leaves that resemble stained glass windows, they’re a showstopper in any setting. But just like any diva, they can be a bit demanding.
But just because they have needs, doesn’t make them too difficult to grow! A little bit of knowledge goes a long way when growing this beautiful indoor plant. This guide will equip you with the knowledge to keep your rex begonias thriving and their foliage looking fabulous.
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About Rex Begonias
Rex begonias (Begonia rex-cultorum) are not your typical flowering plants. While they do produce small, insignificant blooms, they’re prized for their stunning foliage. The leaves come in an incredible array of colors, patterns, and textures, with shades of silver, purple, red, pink, and green swirling together in mesmerizing combinations.
These tropical plants are native to the forests of Northeast India, and they bring a touch of exotic beauty to any indoor space. I am a huge fan of that gorgeous foliage! There are lots of different varieties to grow so choose one that speaks to you and sparks joy
Light Requirements: Bright, Indirect is Key
Rex begonias crave bright, indirect light to maintain their vibrant colors. Think of them as sunbathers who prefer a beach umbrella. Direct sunlight can scorch their delicate leaves (ouch!), so an east- or west-facing window is ideal. If your windows face south, place your begonia a few feet back or use a sheer curtain to filter the light. I keep mine in my sunroom in a west-facing window and it seems to love that location.
Expert Tip: Rotate your plant regularly to ensure even light exposure and prevent it from leaning towards the sun.

Soil Conditions: Well-Draining is a Must
To prevent soggy roots and unhappy begonias, well-draining potting soil is essential. A mix of peat moss, perlite, and vermiculite will provide the perfect balance of moisture retention and aeration. Aim for a slightly acidic pH (6.0-6.5) for optimal nutrient uptake. Lately, I’ve been making my own chunky potting mix with orchid bark, perlite, and potting soil, but I’ve also bought it pre-made chunky soil here.
Expert Tip: Avoid using heavy garden soil, as it can compact and suffocate the roots.

Temperature and Humidity: Comfort is Queen
Rex begonias enjoy average room temperatures (65-75°F). They also thrive in moderate to high humidity, mimicking their natural tropical environment. However, avoid misting the leaves directly, as this can lead to powdery mildew. Instead, increase humidity by:
- Using a humidity tray: Place your begonia pot on a tray filled with pebbles and water.
- Grouping plants together: Plants naturally release moisture, creating a more humid microclimate.
- Running a humidifier: Especially beneficial during dry winter months. I love this cool-mist humidifier that isn’t intrusive and looks good with my home decor.
- Expert Tip: If the edges of your begonia leaves start to crisp, it’s a sign that the humidity is too low.
Watering: The Goldilocks Approach
Watering rex begonias requires a delicate balance. They like their soil moist but not soggy. Allow the top inch of soil to dry out before watering thoroughly. Always use lukewarm water to avoid shocking the roots.
Expert Tip: Overwatering is a common cause of root rot, which can be fatal. When in doubt, underwater rather than overwater.

Fertilizing: A Little Goes a Long Way
During the growing season (spring and summer), fertilize your rex begonia lightly with a balanced liquid fertilizer diluted to half strength. Reduce or stop fertilizing in fall and winter when growth slows down. I usually use this slow-release fertilizer so feeding my begonias are set and forget.
Expert Tip: Too much fertilizer can burn the roots and damage the plant.

Common Problems and How to Solve Them
While rex begonias are generally hardy, they can be a bit sensitive to their environment and may experience some issues. Here’s a troubleshooting guide to help you keep your rex begonia thriving:
Leaf Curl
Causes
Underwatering, overwatering, temperature fluctuations, pests, nutrient imbalances, or disease.
Solutions:
- Water consistently: Water thoroughly when the top inch of soil is dry.
- Maintain stable temperatures: Avoid drafts and sudden temperature changes.
- Control pests: Inspect regularly and treat infestations promptly (more on pests below!).
- Fertilize appropriately: Use a balanced fertilizer at the recommended dosage.
- Ensure good air circulation: This helps prevent diseases.
- Optimize humidity: Maintain moderate to high humidity levels.
Leaf Drop
Causes
Underwatering, overwatering, low humidity, temperature stress, or insufficient light.
Solutions
- Adjust watering: Water when the top inch of soil is dry, but don’t let it dry out completely.
- Increase humidity: Use a humidity tray or humidifier.
- Provide adequate light: Ensure bright, indirect light.
- Maintain stable temperatures: Avoid drafts and extreme temperatures.
Brown Leaf Edges
Causes
Low humidity, underwatering, fertilizer burn, or fluoride in water.
Solutions
- Increase humidity: Use a humidity tray or humidifier.
- Water more frequently: Ensure the soil stays evenly moist.
- Adjust fertilization: Reduce fertilizer concentration or frequency.
- Use filtered water: If fluoride is suspected, use distilled or filtered water.

Leggy Growth
Causes
Insufficient light.
Solutions
- Increase light exposure: Move the plant to a brighter location.
- Prune leggy stems: This encourages bushier growth.
Powdery Mildew
Causes
High humidity combined with poor air circulation.
Solutions
- Improve air circulation: Provide good ventilation.
- Avoid overhead watering: Water at the base of the plant.
- Treat with fungicide: If necessary, use a fungicide labeled for powdery mildew.
Pests of Rex Begonias
Common Pests
Mealybugs, spider mites, aphids, and thrips.
Solutions
- Isolate infested plants: Prevent spread to other plants.
- Manual removal: For minor infestations, remove pests with a cotton swab or by hand.
- Insecticidal soap: Use insecticidal soap for more severe infestations.
- Neem oil: Neem oil can be effective against a variety of pests.
I have been using this systemic houseplant insect control that lasts 8 weeks and works really well. It is a granule and it is set and forget. Love it!
Plant Propagation: Sharing the Love
Rex begonias are easy to propagate, allowing you to expand your collection or share with friends:
- Leaf cuttings: Take a healthy leaf and cut it into sections, ensuring each section has a vein. Place the cuttings in moist soil or water, and new plantlets will form.
- Stem cuttings: Cut a section of stem with a few leaves and root it in water or soil.
- Rhizome division: When repotting, carefully divide the rhizomes (underground stems) to create new plants.

Overwintering Rex Begonias After Growing Them Outside
If you started growing your rex begonias outside during the warm summer months and want to keep them, you can!
Treating Rex Begonias Like Houseplants
This is what I do as I bought it as a houseplant and bring it outdoors to summer. But I’ve seen nurseries sell them in spring for outdoor use like other annuals. This is what I do to help them transition from outdoors to in.
- Before the first frost, bring your potted rex begonias indoors.
- Choose a bright location with indirect light like an east- or west-facing window. Avoid placing them in direct sunlight, which can scorch the leaves.
- Reduce watering as the temperatures cool and growth slows down. Allow the top inch of soil to dry out between waterings.
- Stop fertilizing rex begonias during their winter rest
- Begonias are huge fans of humidity. Increase it by placing the pot on a tray of pebbles filled with water or using a humidifier.
- Maintain a comfortable room temperature – think (65-75°F). Avoid placing them near drafts or heat sources.
Overwintering Rex Begonias in the Basement or Garage
If you lack the indoor growing space, you can overwinter them in your basement or garage. Here’s what you need to know.
- Pre-Frost Move: Bring your potted rex begonias to the basement or garage before the first frost.
- Temperature and Light: The ideal basement or garage temperature for overwintering is between 45-55°F. Begonias don’t need much light during their dormancy, so a dimly lit space works well.
- Minimal Watering: Water sparingly during the winter months, just enough to prevent the soil from completely drying out. I almost leave mine completely alone!
- Spring Awakening: In early spring, move your begonias to a brighter location in the basement or indoors. Gradually increase watering and fertilizing to bring them out of dormancy.
To read more about overwintering begonias, read this article that I wrote about how to do it successfully.

Final Thoughts About Growing Rex Begonias
While Rex begonias require a bit more attention than some other houseplants, they are definitely manageable. With the right conditions and care, you can enjoy their stunning foliage for years to come.
If you’re a beginner, you might want to start with an easier type of begonia, such as a wax begonia, and then graduate to rex begonias once you have more experience.
I absolutely adore growing rex begonias! The details of each leaf get me every time and bring me joy to care for. While they can be a little fussy at times, the reward of seeing those stunning leaves unfurl is well worth the effort. I encourage everyone to give these “drama queens” a try – you won’t be disappointed!
For more information about caring for rex begonias, please read this article from the University of Connecticut Cooperative Extension.
To drill down on houseplant care basics and growing an indoor garden that thrives, please read my articles:
- Easy Houseplants for Busy People: The Low-Maintenance Approach to Growing an Indoor Garden
- From Shop to Home: How to Acclimate Your Tropical Plants
- Stop Guessing and Master Watering Indoor Plants Like a Pro
- How to Revive Houseplants You Thought Were Goners
- Is Your Houseplant Getting Enough Light? Here’s How to Tell.
Thank you for visiting the blog today!
Enjoy your day! xo

