How to Grow and Care for Begonia Rex Indoors and Outdoors
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Begonias are members of the fifth most significant family of ornamental plants and are well known for their beautiful leaves and attractive flowers. They produce bright-colored full blooms and multi-colored leaves with showy patterns. Therefore, begonias are popular bedding plants in landscapes and as houseplants indoors.
These beautiful foliage plants occupy tropical regions worldwide (that is why they are a popular choice for landscapes) except in Australia and are super sensitive to cold. Some begonias are grown for their exquisite summer flowers, such as wax begonia, tuberous begonia, ‘Dragon Wing’ begonia, and trailing begonia. At the same time, others are commonly grown indoors for their magnificent leaves, such as cane-like begonia and rex begonia.
Among these various types of begonias and newer hybrids, the rex begonia (begonia rex- cultorum) is a favorite of every plant collector. They have the most vibrant leaves with unique color combinations and patterns.
Let’s learn more about rex begonia, their care tips, and how to grow and maintain this rhizomatous indoors and outdoors.
What is Begonia Rex Here?
Begonia rex or painted leaf begonias are herbaceous perennials, mainly known for their leaf variegations. They produce brightly colored leaves in green, red, purple, pink, black, maroon, silver, and brown shades. However, they do make small pink or white-colored flowers during the growing season but are of no significance compared to variegated leaves. Their colorful foliage makes them the best houseplant for interior decorations and landscape aesthetics.
The begonia rex plant includes many different cultivars and hybrids produced by king begonia and other begonias.
All these resulting hybrids are grouped under one group, Begonia rex-cultorum. These plants are famous for their dark leaves with grey or silver patterns. Begonia rex-cultorum is referred to as rhizomatous begonias (native to India) for their thickened stem from which fancy leaves arise.
Most famous cultivars of this group include ‘Escargot’ and ‘froggy.’
Begonia Rex Cultorum Care Guide
USDA Hardiness Zones
Popular Begonia Rex Varieties
Around 1850, the cultivation of rex begonia and its various hybrids became famous as a houseplant mainly for their colorful leaves. Its cultivars present unique leaf patterns and enhance the aesthetics of interiors and patio.
There are thousands of cultivars of king begonia for houseplant collectors and landscape enthusiasts. The foliage of these cultivars comes in many shapes, such as snail-shaped, ear-shaped, and star-shaped.
These varieties include fairy, rumba, tornado, pink charming, ‘Red kiss Rex,’ ‘Duarte,’ ‘Salsa,’ ‘Spitfire,’ blueberry sorbet, ‘Fireworks,’ etc. Among these varieties, the most loved are ‘Escargot’ cultivars and froggy.
What Does Rhizomatous mean?
Rex cultorum is a rhizomatous begonias group, meaning these plants have rhizomes. A rhizome is a swollen underground plant stem that grows horizontally into the soil. However, in the case of rex begonias, the thickened stem rise vertically above the ground with upright branches, from which fabulous leaves emerge. In comparison, other cultivars of rhizomatous begonia serve as groundcover and prevent the growth of grasses and weeds.
They not only mechanically support the plant but also help the perennials to survive in harsh environmental conditions. Rhizomes store water and nutrients to feed and supply the energy to the aboveground plant during winter. The ornamental rhizomes include begonia rex, while the edibles include potato, ginger, and turmeric.
How to Grow Begonia Rex
Begonia rex is a charming plant mainly admired for its leaves. These plants are a bit demanding whether you grow and maintain them indoors or outdoors. They grow best in USDA hardiness zones10-12 and produce uniquely patterned leaves in indirect light and high humidity with good air circulation. While their temperature needs are between 65 to 75 degrees Fahrenheit.
During the growing season, the begonia rex flowers are insignificant in front of striking leaves.
To grow the begonia rex successfully, use seeds, leaf cuttings, stem cuttings, and rhizome division. Among these methods, the most rewarding way is propagation through rhizome division and leaf and stem cuttings.
Growing begonia rex indoors and outdoors involves the following steps;
Select the right location for rex begonias indoors and outdoors. The east-facing windows are ideal where king begonias receive gentle morning sun followed by shade for the rest of the day. Outdoors grow the begonia rex in partial to full shade, such as under a tree or hanging baskets.
Instead of microscopic seeds of begonia rex, use stem and leaf cuttings to grow a happy and healthy plant.
Use large shallow pots with fertile and well-draining soil to provide ample room for root growth.
Plant the rhizome division into the holes and gently cover them with soil.
Mist the soil surface with water to stimulate root development. Remember to reduce the watering in the winter months, as begonia rex undergoes the dormant stage.
When growing begonia rex indoors as houseplants in containers or large shallow pots and hanging baskets, position them in bright but indirect light. It is wise to keep them on windowsills, especially the east-facing. If grown with south- or west-facing windows, keep the begonia rex containers a few feet away to avoid direct sunlight or cover the windows with fiber to filter the light.
Begonia rex makes the best ground covers and likes the sites with deep or complete shade. These tropical plants are herbaceous perennials in USDA hardiness zones 10-12 and grown as annuals in landscapes and houseplants.
How to Care for Begonia Rex
Rex begonia plant care is a bit demanding regarding water, humidity, and light (indirect light is best for them) requirements. However, the begonia rex-cultorum are easy to care for with knowing their care guide tricks.
The following are essential care tips for begonia rex to keep growing them healthy and happy:
Begonia rex needs regular watering to grow healthily but still avoid overwatering to prevent the root rots. Allow the soil surface to dry between each watering, and always drain the excess water to keep the roots healthy and happy.
How much water do rex begonias need?
Rex begonias prefer regular and consistent watering. However, you want to avoid overwatering and creating soggy soil which can lead to root rot and fungal diseases.
Do rex begonias need distilled water?
Rex begonias can be sensitive to chemicals in tap water because tap water is filled with high mineral salt content. Build up of excess salt can cause leaf edge burn in rex begonias. You'll want to flush your soil regularly with distilled or rainwater if you've been using tap water to water your rex begonia.
Why is my rex begonia drooping?
A drooping begonia is a sign that it's thirsty! You'll want to water it more consistently. It could also signify that your begonia isn't getting enough nutrition from the soil. If you haven't refreshed the soil in a while, it may be time for a repot or throwing in some balanced fertilizer to replenish micro and macronutrients.
A partial shade will satisfy the light needs of begonia rex because these ornamental plants are not aggressive bloomers. They need bright, indirect light to grow and produce multi-colored leaves. Under artificial fluorescent lights, the rex begonias have healthy and beautiful foliage.
Avoid direct sun direct sunlight exposure to protect their leaves from burning.
Can begonia rex take full sun?
Rex Begonias thrive best in bright, indirect light. They can tolerate a couple of hours of direct sunlight, but overexposure to direct sun can scorch the leaves.
Why is my begonia so leggy?
Begonias need bright light in order to grow well. If your begonia is growing in a leggy manner, it's likely a sign that they need more light. Place them near east or west-facing windows if growing indoors.
Temperature and Humidity
Begonia rex does well in warm climates. Therefore, the temperature range should be between 65 to 75 degrees Fahrenheit for these tropical plants. Avoid the cold temperatures when begonia rex is grown outdoors and transfer them indoors.
Like other begonias, the begonia rex needs moderately high humidity (approximately humidity levels of 50% are best). The humid environments with good air circulation favor the healthy foliage growth of these tropical plants. When indoors, the best moist locations for begonia rex are the kitchen and bathroom.
In the cases of dry air, use a humidifier and water misting to maintain desired humidity levels.
Begonia rex requires fertile, well-draining, peat moss-based soils to thrive happily. On the other hand, if you grow your rex begonia outdoors, select a site with well-draining soils and good moisture levels.
A good potting soil mix for indoor containers should have all ingredients such as peat moss, perlite, and vermiculite. Also, use large shallow pots with suitable drainage holes to provide the rhizome with a good nutrient and oxygen supply.
During the growing season (spring and summer) of begonia rex, feed them with liquid fertilizers every two weeks at half strength.
Cutting and Pruning
Good begonia rex care involves regular pruning because of its fast-growing habit and can reach up to several inches tall. Therefore, cut off the excessive growths or primary stem to the ground level. Also, check for weak, damaged, or diseased leaves to ensure the fuller and healthy growth of the plant.
How to Propagate Begonia Rex
Begonia rex is easy to propagate but needs little extra care and careful maintenance practices. The best propagation ways for these stunning plants are rhizome division, stem, and leaf cuttings. During repotting your favorite begonia rex plant, divide the rhizomes of the mother plant into two or three parts.
Place each divided rhizome into various pots with fertile and porous soil medium. Regularly water them until new growth emerges and develops into a new plant.
How to Repot Begonia Rex
Begonia rex is an eye-catching plant and great for indoor decorations and patio gardens. These tropical plants need repotting once every two years for fresh potting soil mix and larger pot (more space for rhizomes to grow). Following are the steps involved in repotting rhizomatous begonias;
Gently shake the sides of the pot and remove the begonia rex from its current pot.
Remove the old potting soil mix from the rhizome.
Prepare a fresh potting mix with equal amounts of peat moss and perlite to give the Begonia rex a fertile and well-draining soil for a new start.
Always select shallow pots with suitable drainage holes about 2.5 inches larger than the previous one.
Fill the pot with a new potting mix and place the plant in a new growth medium.
Water the newly repotted begonia rex and situate it in the shade.
Note: Becareful about overwatering your begonia rex!
Remember not to overwater the recently potted begonia rex; otherwise, it will attract fungal and bacterial infections. The best to perform repotting is spring when the plant is starting new growths.
Common Begonia Rex Problems and Pests
Unlike orchids or other houseplants, the begonia rex are not immune to microbial diseases and pest problems. The damage of these pests appears heavily on foliage and impacts their aesthetic value.
Here are the most common issues of Begonia rex:
Less humid conditions trigger the infection of gray mold fungus, which covers leaves, flowers, and stems. To get rid of botrytis fungus, remove the diseased leaves and flowers before spreading them over other houseplants.
It is a fungal infection favored by extreme moisture conditions. Powdery mildew fungus produces white, fine spore masses on the top of leaves. The high temperatures kill the fungus and its spores. To kill infection, try to relocate the begonia rex to warm temperatures for a few hours.
Overwatering is the leading cause of root rot in begonia rex. The extremely wet conditions favor the growth of powdery mildew and blight fungus, which multiplies on the underside of leaves, and brown or black patches appear on the upper side.
Ensure the soil is dry between each watering session to discourage root rot.
The most common insect pest infestations of Begonia rex are mealybugs, whiteflies, aphids, and scale insects. These outdoor bugs suck out plant juices and discolor the striking foliage of Begonia rex. The regular spray of neem oil and dish soap water can prevent their damage by making them unconscious and dead.
5 Tips on How to Take Good Care of Begonia Rex
The five most essential care tips for Begonia rex are;
- Plant the begonia rex in large shallow pots when repotting them.
- Locate the begonia rex plant with indirect light; otherwise, direct sun exposure will burn their leaves.
- Potting soil mix for begonia rex should be airy, fast-draining, and peat moss-based soils.
- Maintain high humidity with good air circulation for begonia rex to grow beautiful leaves.
- Monitor the plants for insect pests and microbial diseases. Prune off the weak and diseased leaves to prevent further infection spread.
Where to Buy Begonia Rex?
Rex begonias are gorgeous plants with showy foliage. Their foliage comes in different shapes and unique color combinations. When these beauties are grown indoors, they enhance the aesthetics of interiors, while outdoors in hanging baskets and landscapes, rex begonias are the center of attention due to their brightly colored leaves.
Get these stunning plants from Neverland with a complete care guide for indoor and outdoor environments.
Common FAQs on Begonia Rex
How long do Rex begonias live?
Like all begonias, the rex begonia lives around two to three years with optimum growing conditions.
Do rex begonias like sun or shade?
Rex begonias like bright, indirect light to thrive well and complete shade outdoors.
Should you mist Begonia rex?
Rex begonias grow happily in high humidity but dislike water on their foliage because wet leaves are more prone to fungal infections (gray mold and powdery mildew).