Guide To Care For Begonia Rex

Begonia Rex Care

Rex Begonia is a tropical plant that comes in a variety of leaf shapes and colors and can add more beauty to your home. Although certainly eye-catching, some people claim that it can be a fussy plant to maintain. 

Rex Begonia isn’t difficult to grow and maintain, but you need to ensure moist, sunny conditions for it—think tropical environments. This will ensure your plant stays healthy. 

Continue reading this article to learn more about how to care for Begonia Rex. We’ll also look at some interesting facts about its history and some growing tips for it. 


Begonia Rex Origins

Begonia Rex is a rhizomatous perennial plant that originates from northeastern India, Vietnam, and China. It’s specifically found in areas such as slopes, forested valleys, and rocky locations. This plant got its name from Michael Bégon, who was a patron of botany and the governor of French Canada during the 1700s. 

Around the 1850s, Begonia Rex was introduced to the horticulture industry and started to be crossed with other begonias. This has since resulted in the plant’s hybridization, which has made it display bold and unusual parts that vary in different plants. 

Some Begonia Rex plants have asymmetric leaf shapes, while others are ovate. They also vary in their leaf patterns, with some having spots, streaks, or swirls on their leaves. 

Expanding Zones/Conditions 

Begonia Rex performs well in U.S. gardening zones 10–12, as it becomes hardy in these environments. 

Zone 10 experiences mild winters and hot summers, while Zone 11 and 12 also have warm temperatures. 

These conditions are ideal for Begonia Rex, which requires moderate temperatures of approximately 60–70 degrees Fahrenheit. It also requires a moderately high humidity of around 50 percent. 

How and Where to Grow 

Best place to grow Begonia Rex

Begonia Rex will slow down its growth during very cold temperatures. Some plants go into dormancy during winter. This occurs as a result of less light. Take this into consideration when choosing the best spot in your garden for Begonia Rex. 

In the summer, make sure your Begonia Rex is in an area of shade in the garden to prevent the sun from burning its soft, large leaves. These come in a variety of colors, such as red, that you’ll want to keep healthy because they’re so striking! Read our guide, 10 Houseplants With Red Leaves

You can also store your Begonia Rex in potted plants in the home. 


The leaves of a Begonia Rex can reach up to 12 inches in length and 8 inches in width. This plant also blooms small pink flowers on stalks that can be up to 12 inches long. 

Begonia Rex is a plant that grows densely, so you need to be careful when planting a group of them together. They shouldn’t be crowded as this can cause stunted growth due to the lack of light and air. 

Soil Type 

Favorite Begonia Rex Soil

Begonia Rex requires soil that’s slightly acidic, so it should have a pH of between 5.7 and 6.2. Its ideal soil type is porous, so it needs to be light and fast-draining. Porous soil types have coarse particles with large holes in them. Although Begonia Rex likes humidity, it doesn’t want soggy soil!  

If you’re planting Begonia Rex in a pot, add a peat-based potting mix to the soil. This is light, and the peat ensures adequate drainage. 

Light, Water, and Fertilization

Begonia Rex likes being in an area of the garden or home that gets bright but indirect light throughout the year. Although this light can sometimes be tricky to get right, it refers to light that is bright enough to form a shadow. It’s commonly found near north- and east-facing windows of the home.

When planting your Begonia Rex outside, it will do well in areas of partial shade. Although its leaves might be colorful and patterned, these plants don’t require full sun conditions in order for the process of photosynthesis to take place. 

A good tip when keeping your indoor Begonia Rex happy and healthy is to rotate its pot regularly so that you ensure all parts of the plant receive enough light. 

Note that in Zones 10 and 11, your Begonia Rex plants can be successfully grown outdoors because they thrive in the heat. If you live in cooler regions, it’s a good idea to bring them inside when temperatures drop during autumn and winter. 

Although Rex Begonia plants like humid conditions, you should only water them when their soil feels dry. To increase their humidity, you can mist their leaves. This should be done with caution, as you don’t want the leaves to stay wet.

After watering your plant, its soil should feel evenly but lightly moistened. You shouldn’t let the soil become too dry or wet as this will damage the plant.

When it comes to fertilizer, you should fertilize your Rex Begonia regularly when it’s actively growing in the spring. It requires an all-purpose, water-soluble fertilizer for houseplants. Apply it at quarter strength and reapply it every two weeks. 

Growing Tips 

Reppoting Begonia

Begonia Rex has tiny seeds that need warmth to germinate. Keep the seeds in temperatures of between 70 and 75 degrees Fahrenheit until they germinate. This can take about two or three weeks. 

After you’ve placed your Begonia Rex seedlings into holes in the soil, cover them with soil and water them generously. This will help the seedlings to settle and take root.


When planting Begonia Rex in pots, make sure that the containers are shallow but wide, because this plant has rhizomes that grow horizontally and require plenty of space. 

When you can see that the plant’s rhizomes are pushing against the pot, this is a sign that it’s time to repot the Begonia Rex into a new pot with fresh soil. 

After repotting your plant, water it lightly and keep its soil light and moist without soaking the soil too much. Read our guide, Best Potting Soil For Your Urban Garden

Ongoing Care 

Potting Advice

Regularly pruning your Begonia Rex keeps its foliage bushy. When pruning, remove any dead leaves so that the plant can grow healthily. 

While you should give your Begonia Rex fertilizer during its growing season, you should reduce this during the fall and completely stop feeding it in the winter as it goes into a dormant period. 


Begonia Rex is susceptible to various diseases, we’ll discuss them below.

Botrytis Blight (Gray Mold) 

Botrytis Blight is a fungal disease that appears as brown spots on the stem and leaves of the plant after a cool and wet period. You might also see gray mold on the plant. 

To prevent it from affecting your Begonia Rex, make sure you: 

  • Avoid overcrowding your plants
  • Avoid giving your plant too much nitrogen 
  • Avoid watering the leaves

Powdery Mildew 

This mildew is caused by a fungus that produces a white powder-like coating on leaves. In serious cases, the plant can become stunted, and its leaves can become yellow as well as withered. 

To prevent mildew from affecting your Begonia Rex, avoid overcrowding your plant or keeping it in shady conditions. If the nights are cool, bring your potted plants indoors. 

Pythium Root and Stem Rot 

This is a severe fungal disease that causes the stems to become filled with water and collapse so that they cannot support the plant anymore. Other symptoms that will show up on your plants include black and rotting roots, as well as dark foliage. 

Pythium fungus thrives in wet soil, so be careful of any infected soil or cuttings from plants that have been diseased. Keep your plants healthy, as this can also ward off this type of disease. 


Diseases on Begonia

Diseases aside, Begonia Rex can also be attacked by various pests, as described below. 

Mealy Bugs 

Mealy bugs are small insects that suck the sap of plants. They commonly attack tropical houseplants. They’re drawn to plants that have high levels of nitrogen and are watered too much, so make sure you’re not giving your Begonia Rex too much nitrogen-based fertilizer or too much water. 

If your Begonia Rex has mealy bugs, you’ll notice that it’s wilting, losing leaves, or experiencing stunted growth. 

If there aren’t many bugs on your plant, you can remove them with a cotton swab that’s been dipped in rubbing alcohol. For more serious infestations, you’ll need neem oil. Make sure you spray this oil all over the plant.

Spider Mites 

Check for holes in leaves

Spider mites are drawn to plants that are in direct sunlight, as they thrive in warm conditions. Prevent them from attacking your Begonia Rex by keeping it in indirect, not full, light. 

Spider mites are arachnids that suck plant juice from the leaves of plants, leaving them looking yellow, dry, or blotchy. 

To remove spider mites, wash them off the plant with water—just be careful to ensure that the plant leaves dry to prevent mildew—or spray them with neem oil. 


Thrips are small, thin, winged insects. They suck out nutrients from your Begonia Rex’s delicate tissues, which can cause the plant to become distorted or discolored. You’ll have to remove thrips by spraying water on them. If this doesn’t work, a stronger solution, such as neem oil or insecticidal soap, is recommended. 

Thrips are attracted to areas of the garden where there are lots of weeds, so make sure you weed regularly. You should also keep the area free of ground debris, which thrips can use as hiding areas. 

Slugs and Snails

Slugs and snails are two other pests that are attracted to moist environments, so again, make sure you don’t water your Begonia Rex too much. What makes it tricky to eliminate them is that they are most active at night.

A good way to check for them is to check your plants with a flashlight after dark. If you don’t see the snails themselves, you’ll see large holes in the plant’s leaves and possibly even slime trails on them. 

Using slug and snail bait will remove them from your plants. You might also want to bring outdoor potted plants indoors overnight. 


If you’re growing Begonia Rex in your home or garden, you’ll naturally want to know how to care for it. Although it’s sometimes said that this houseplant with tropical origins is difficult to look after, that’s not really true. As long as you follow the essential tips we’ve outlined in this article, you’ll watch your Begonia Rex thrive. 


About The Author

Gina Harper grew up dreaming about farms and growing her own food. She began an urban garden to feed herself and turned it into an incredible hobby. Gina is here to teach you everything from raised beds to container gardening, how to keep plants alive and well in a smoggy city, and the works. It’s time that we carve our own piece of green earth and reap what we sow—she’s here to help you with that.