Begonia Rex Soil & A Short Care Guide

Finding the right begonia rex soil is the second step of keeping your plant thriving in a container (after having selected a pot with proper drainage).

begonia rex soil

Nail the recipe and you might even be able to revive an ailing rex begonia. But how can you achieve it?

This post is all about rex begonia soil from principles to practical ideas, so keep rolling!

Begonia Rex Soil Principle

Rex begonias, also known as painted-leaf begonias or fancy-leaf begonias, are prized for their beautiful variegated leaves in colors like bright green, silver, purple, and red. 

For thriving rex begonias, the key lies in utilizing a soil that is both airy and light while quick draining and slightly acidic.

In containers, the preference leans towards a well-aerated peat-based potting soil, specifically tailored to accommodate the delicate root systems of rex begonias.

begonia rex soil

Based on this principle, you are having more than just one soil mix option to cater your delicate Rex Begonia plant.

If it still shows signs of stress regardless, you might as well suspect if the pot you’ve chosen has the appropriate features for it.

Begonia Rex Soil Ingredients

For a fast-draining soil, consider these ingredients: peat, vermiculite, pearlite, orchid bark, and coco chips. 

I would also recommend layering charcoal at the bottom of the pot, as this serves to enhance drainage and prevent the risk of waterlogging.

Charcoal acts as a natural filtration system, ensuring that excess water can freely escape, thus safeguarding the roots of your begonias from potential rot or overhydration.

This simple addition promotes a well-balanced and aerated environment for your indoor begonias, aligning with their preference for soil that is both moisture-retentive and well-draining.

begonia rex soil

My Usual Begonia Rex Soil Mix

For a standard potting mix, I normally incorporate 50% African violet soil, which contributes a slight acidity as per the habit of Rex Begonia.

To enhance the mix’s texture and drainage capabilities, I include 25% perlite, providing aeration and preventing soil compaction.

Additionally, I also mix in 25% orchid bark to further improve drainage and add organic matter, creating an environment that mimics the natural conditions. 

For a simpler approach, some gardeners opt for an equal blend of perlite and soil, and their Rex Begonias thrive just as well with this uncomplicated mixture. 

begonia rex soil

Begonia Rex Soil For Indoor Growth

For optimal growth of indoor Rex Begonia, it is advisable to utilize a soilless mix.

While most prepackaged mixes designed for indoor cultivation of begonias are suitable, incorporating perlite may be necessary.

Avoid adding ingredients such as oak leaf mold to indoor growing mixes.

Remember that indoor mixes need to be one that retain moisture and nutrients while providing a supportive structure for the roots.

Consider the following mix:

  • 1 part coconut-based planter mix
  • 1 part small-sized orchid bark (1/8 to 1/4 inch)
  • 1 part perlite

To further enhance the growing conditions, the application of bokashi or an all-around fertilizer is recommended during the active growing seasons.

begonia rex soil
Orchid Bark

Other Begonia Rex Plant Care Tips

When it comes to caring for your rex begonia plant, there are a few key points to keep in mind. Let’s explore them in more detail:


Regular watering is essential for rex begonias, but be careful not to overwater.

Allow the soil surface to dry out before watering, and avoid getting the leaves too wet to prevent powdery mildew.

Check the soil before watering, and remember to use well-draining soil.

Lighting Needs

Rex begonias thrive in bright indirect light but should be shielded from direct sunlight, especially in more southern climates.

In northern climates, some direct sunlight is acceptable, but it’s best to bring the plant indoors during cooler months.

begonia rex soil


Rex begonias prefer moderate temperatures between 60°F and 70°F.

Avoid exposing them to temperatures below 60°F, as it can harm their growth.

Some rex begonias may go dormant in winter if they don’t receive enough light.


Rex begonias require high humidity levels of over 50%.

Growing them indoors during winter can be challenging due to dry air.

To increase humidity, you can group them on a water-filled pebble tray or use other methods to create a humidified environment.

begonia rex soil


Start fertilizing your rex begonias in spring when they begin to grow.

Use a quarter-strength or half-strength liquid fertilizer every two weeks.

Avoid feeding them during winter, as their roots won’t be able to absorb nutrients.

Growth Zone

Rex begonias are considered perennial plants in tropical and semitropical settings. In North America, they can be grown as indoor plants in USDA zones 10 and 11.


Choose a pot with drainage holes to ensure proper drainage and prevent root rot.

Rex begonias have shallow, rhizomatous roots and thrive in large shallow pots. Repot them when the rhizome grows against the pot’s sides.

begonia rex soil


Rex begonias generally need minimal pruning. Remove any dead or rotting leaves to keep the plant healthy.

If you want to create a fuller look, you can cut long, barren stems down to the base, and new leaves and stems will grow.


Rex begonias can be easily propagated through leaf cuttings or rhizome division.

Leaf cuttings involve selecting a healthy leaf, cutting it into sections, and planting them in well-draining potting soil.

Rhizome division is done during repotting, and each section should have a portion of the root system and at least one stem with leaves.

begonia rex soil

Rex Begonia Diseases & Pests

As with any plant, rex begonias can be susceptible to diseases and pests. Here are a few common issues to watch out for:

  • Pests: Mealybugs, aphids, caterpillars, slugs, and snails can sometimes infest rex begonias. Manage outbreaks of mealybugs by dabbing them off the plant with alcohol-soaked cotton balls or swabs. Insecticidal soap can help control aphids and caterpillars. Use slug bait to prevent invasion by slugs and snails.
  • Diseases: Rex begonias can suffer from Botrytis leaf blight and powdery mildew. Avoid overwatering and ensure good air circulation to prevent these diseases. Remove infected leaves and water the plant properly to control the problems.

With this complete guide, you now have all the information you need to grow and care for your rex begonia plants.

Enjoy the beauty of their vibrant and textured leaves, and create a stunning indoor garden with these unique plants. Happy gardening!