Rex Begonia Plant Care

Did you know that rex begonia is considered perennial in tropical and semitropical regions but grown as annuals in North America? Although rex begonias have exquisite flowers, they are more commonly planted for their vibrantly colored and intriguingly textured leaves.

Dark leaves with pronounced silvery grey stripes distinguished these plants. They are begonias with rhizomatous roots. A rhizome is a thickened stem that produces leaves. Want to have another breathtaking indoor houseplant? Read more below to learn more about rex begonia care tips.

It’s a good idea to know the rex begonias step by step. So here’s an overview of it:

Botanical name: Begonia rex-cultorum

Other names: Fancy-leaf, Painted-leaf or King begonias

Plant type: Herbaceous perennial

Exposure to sunlight: Bright, indirect light year-round

Soil type: Porous potting soil

Color: Brightly colored in various shades of green, red, silver, and even purple

Water: Filtered water

Favorable temperature: 60 to 70 degrees Fahrenheit (15.5 to 21.1 degrees Celsius)

Preferable fertilizer: Liquid fertilizer

Propagation: Rhizome division

Toxicity warning: Toxic

Height: 12 to 18 inches

Origin: Northern India

Now that you’ve known the overview of the Begonia rex plant, we’ll dive deep into learning how easy growing rex is.

Rex Begonia Plant Care Basics

rex begonia plant

Soil Requirement

A high-draining soil is vital for a Begonia rex. With that being said, plant them in a porous, well-draining potting mix with peat moss and leaf mold. Instead of retaining all that unnecessary water, porous soil enables it to drain. Porous soil can also help your plant maintain the moist soil it requires to flourish. Additionally protects the plant from root rot while keeping it sufficiently hydrated. Rex begonias also grow in African Violet potting mixtures.

Water Requirement

Regular watering is vital for a Begonia plant. However, be careful not to overwater them. The painted leaf begonia should be watered evenly throughout the summer and growing season. Before watering, allow the soil surface to become dry when you touch. It is preferable to keep the soil somewhat drier.

But never fully dry out the soil since this can soon kill your rex begonia. It’s best not to get the leaves too wet, as this can lead to powdery mildew. Your painted leaf may go dormant and drop its leaves in the winter months. Continue to give it only a little water until new leaves emerge in the spring.

Take note, check the soil first before watering. Overwatering is a kiss of death for the rex begonia.

Lighting Requirement

begonia lighting requirement

Bright indirect light is excellent for the painted leaf begonia. It will need to be shielded from the direct summer heat and sunlight in more southern climates, but you can plant it outside all year. While some sun shouldn’t be an issue in more northern climates, but take the plant indoors during the cooler months.

Some direct sunlight is good for brief periods, especially from an eastern window with milder morning sun. Yet, you may easily deflect direct sunlight with sheer curtains or by placing the plant a few feet away from a facing window with bright light. It’s because its foliage might be burned by too much direct sunlight. 

It may be placed indoors or outdoor, as long as you provide them the proper amount of light rex begonia needed.

Temperature Requirement

Changes in temperature and humidity and temperatures below 60 degrees Fahrenheit are harmful to Begonia rex. With that, moderate temperatures such as 60 to 70 degrees Fahrenheit (15.5 to 21.1 degrees Celsius) are great for rex begonias. When temperatures drop below freezing, their growth slows. Some begonias lay dormant in the winter due to a deficiency of light.

Humidity Requirement

Humidity appears to be an essential factor in achieving optimal leaf size in plants. The Begonia rex plants require high humidity (greater than 50%). That is why growing rex begonias indoors during the winter can be challenging. Try to avoid dry air at all costs. If you’re growing in containers, group them together on a water-filled pebble tray.

This results in a humidified environment with less dry air. Also, avoid spraying the plant’s leaves. This can lead to spots due to uneven humidity air circulation.

Fertilizer Requirement

When your Begonia rex cultorum starts to grow in the spring, start fertilizing them. Every two weeks, apply a quarter-strength or half-strength liquid fertilizer to your plants. During the winter, don’t feed your houseplants because they aren’t actively thriving.

This implies that their roots won’t be able to absorb the nutrients and may suffer harm as a result.


leaf cutting propagation

Leaf-cutting or rhizome division is an easy way to propagate rhizomatous begonias. And the rex begonia is one of those. You can do this by transplanting the plant or other times (though it will take longer in the winter). 

Here’s how you’ll go about it:

  • Using a spade, remove the rex begonia tuber from the pot. The tuber should not be nicked or sliced.
  • Scrape off any excess soil and look for buds on the rhizome. These bumps are pink or red in color.
  • With a sharp knife, cut apart the tuber, leaving three developing eyes on each piece.
  • To avoid infection, apply fungicide to each cut surface of the roots.
  • Fill an 8-inch-diameter pot halfway with a soil mix that drains well.
  • In each container, plant a tuber segment. Next, plant the root with the flat or concave portion facing up.
  • Keep a moist soil but not soggy in a well-lit environment.

Growth Zone

plant growth zone map

In tropical and semitropical settings, rex begonias are considered perennial. Rex begonias are understory plants that grow in their natural habitat shaded to partially shady parts of jungles.

Frost is also a problem for rex begonias. USDA zones 10 and 11 are suitable for this kind of begonias. In North America’s zone 10 and 11, they grow rex begonia as indoor plants.


As long as drainage holes are at the bottom, any pot or hanging basket will work. Yet, root rot and eventual plant death are stimulated when plants are potted in non-draining containers. Rhizomatous plants, such as rex begonias, grow from a shallow, knobby rhizome. As a result, they thrive in large, rather shallow pots with plenty of room for the rhizome to develop. When the rhizome starts to butt up against the pot’s sides, it’s time to repot it with new soil.


Rex begonias need minimal trimming unless they have long, barren stems that need to be pruned back. Alternatively, if you want to make a fuller plant cut the stem down to the base with clean pruning snips, and the remaining section should produce new leaves and stems.

To keep the plant looking good, make sure you trim away any dead or rotting leaves. Pinching the tips of young plants also encourages them to become fuller.

Rex Begonia Varieties and Similar Plants

Many attractive hybrid rex begonia variants exist. Unfortunately, some are frequently unlabeled or mislabeled. Here are the most stunning varieties of rex begonia you may grow in your garden, with asymmetrical foliage, vibrant colors, and patterns:

  • Begonia rex ‘Boston Cherries & Chocolate

Is a rex-type plant with dark purple leaves that have medium spherical pink and silver dots. It’s a pretty simple rex to grow.

  • Begonia rex ‘Snow Queen’

This comes with striking silver-colored leaves. It’s also disease-resistant, which is the advantage of this plant.

  • Begonia rex ‘Escargot’

This is an evergreen, rhizomatous perennial best known for its spiral-shaped foliage coiling around the leaf’s base. The spiraling green, silver, and chocolate colors highlight the snail curl design. That’s producing an eye-catching design.

Rex Begonia Diseases & Pests

Diseases and pests in your gardening are inevitable. That is why looking out for those is essential in your rex begonia care guide.


Rex begonias are subject to mealy insect infestations when the temperature inside is warm. Immerse a cotton ball or swab in alcohol and dab the mealybugs off the plant to manage an outbreak. You can also use alcohol to spritz the entire begonia. Just ensure not to get any on the soil.

Aphids and caterpillars can also be a concern. Most of the time, spraying the bugs with insecticidal soap will solve the problem. In addition, you can control the invasion of slugs and snails by using slug bait near your plants.


Botrytis Leaf Blight

It affects the lowest leaves that come into touch with the soil, and it manifests itself as water-soaked, dark lesions that become larger over time. Prevent the situation by watering according to your schedule. Plus, avoid putting water on the leaves and water early in the day, so the foliage has time to dry before nightfall.

Powdery mildew

Happens when the soil is maintained excessively damp, and the foliage becomes soaked. A white powdery substance covering the leaves is a sign. Remove sick leaves, water properly, and avoid getting the foliage damp to control the problem.

Whether you want to buy, sell or simply reach out to other plant enthusiasts, Plantly is the right place to be!

Frequently Asked Questions

Because these plants are native to high-humidity environments, they don’t perform an excellent job of pumping water to the leaf edges. Therefore, water should not be sprayed on rex begonias. Although misting creates humidity, begonias are prone to powdery mildew, so keeping the leaves dry is preferable.

The most prevalent causes of begonia wilting are overwatering and underwatering. Begonias shrink quickly when their soil dries out, yet keeping the soil too damp can cause dramatic drooping from root rot. Drooping can be caused by various factors, including temperature stress, transplant shock, pests, and disease.

Unfortunately, rex begonias are toxic to both cats and dogs. Soluble calcium oxalates poison cats. And are found in all begonia species. Calcium oxalates are located in the highest concentration in the roots of this plant.

The best is yet to come! You can now purchase Rex begonias here at Plantly! Grow your gardening flowers by messaging us now!

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