everything you need to know – ISPUZZLE

Yellow Begonia ‘Terry’

In our previous grow guide, we explained how begonias can brighten up your garden with their colorful, long-lasting flowers and pretty leaf patterns. But begonias can be equally happy houseplants and can be grown indoors year-round.

The trick to growing begonias as houseplants is in the variety you choose. Here are my recommendations (from easy to hard) to set you up for success.

What begonias can I grow as a houseplant?

If it was a video game about begonias, you could choose four difficulty levels:

single mode: Rhizome begonias and semperflorens (wax) begonias are relatively easy to grow indoors, even for first-time parents.

medium fashion: Rex begonias can be grown indoors as long as they have enough humidity (more info below)

Cane begonias and rex begonias grown in pots.

Hard Mode: Cane begonias, like the Insta-popular ‘Angel Wing’ begonia, are a challenge if you’re new to growing houseplants.

Do not try: Tuberous begonias do not do well in indoor containers as they need lots of light and very good drainage. Bulbs are also prone to rotting due to overwatering in an indoor environment. However, you can start tuberous begonias indoors just to anticipate the gardening season, especially if you live in a climate with short summers. But eventually, you need to transplant them into the garden.

Colorful rex begonias take center stage in this collection of indoor plants.

How do I know what type of begonia I have?

I have written about the different types of begonias in this guide. If you buy a begonia from a nursery, this information should also be on the grower’s label.

My advice is to try playing the game on easy mode first. There are so many beautiful wax begonias and rex begonias to choose from to boost your confidence. You can always level up, of course, but you might want to avoid the frustration. Whether or not you succeed also depends on factors beyond your control, such as the type of light and humidity you receive indoors.

Rhizomatous Begonia ‘Freda’

Here’s how to keep your begonia houseplant happy.

What Kind of Soil Do Begonia Houseplants Like?

One of the benefits of growing begonias as houseplants is that you can control the soil they are planted in. Begonias prefer loose, well-drained soil. I know, proper drainage is easy to say, but often hard to achieve. The trick is to add things like vermiculite, perlite, or peat to the soil (about 10-20% of the mix, depending on plant and container size) to help you achieve porous soil.

One of the most important things to consider is water retention in the soil. Make sure the soil doesn’t get soggy and don’t let the begonia roots get soggy. Therefore, never place your begonia in a container without drainage holes all around and avoid pots with only one drainage hole in the middle.

Begonia maculata ‘Wightii’

When planting in containers, it is important to keep the soil well aerated. In the garden, worms and micro-organisms provide aeration, but in indoor pots, the soil tends to compact. When this happens, the air sacs in the soil dissipate, leaving the plant ‘air hungry’. The roots of the begonia plant need easy access to oxygen, so aerate the soil monthly to loosen clumps and prevent compaction.

Aerating your begonia soil isn’t as complicated as it sounds, and you don’t need any special equipment. Carefully stick a toothpick into the surface of the soil every 1 to 2 inches and loosen the soil. Avoid the use of sharp objects such as knives or skewers which could damage the root structure.

Boston fern, begonia semperflorens and African violet

How often should I water my indoor begonia?

Watering a potted begonia is truly a balancing act, as this plant loves humidity but hates getting wet. In fact, the easiest way to kill a begonia is to overwater it. Begonias hold a lot of water in their waxy stems and leaves, but they also put a lot of energy into flowering and spreading quickly. The bulbs and canes of some begonia plants act as little water reservoirs, but these are the same parts that can easily rot if faced with too much water.

How do you know your begonia needs water? Easy, if it is dry not only on the surface of the soil, but also about two inches deep. You can use a toothpick or your finger to test the moisture content. When the soil is dry two inches below the surface, it’s time to water.

Water your begonia when the soil feels dry about two inches deep.

Soak your begonia until water runs out of the bottom of the pot. Then drain all the excess water. Do not forget to also discard the water collected in the container or saucer under the pot.

Another good tip for watering begonias is to avoid wetting the foliage. Tap water not only leaves unsightly marks on the leaves, but can also contribute to the development of powdery mildew.

Begonia semperflorens is easy to grow indoors

What kind of light do begonias need?

Light is a crucial energy source for your begonia, but there are too many good things. When grown in the garden, begonias are considered shade plants, so it’s no surprise that they have the same requirements indoors as well.

Begonias prefer bright indirect light (where bright refers to light intensity and indirect refers to duration). In most indoor spaces, at least in the northern hemisphere, the best place for bright, indirect light is in front of west- and east-facing windows, and a few feet from south-facing windows.

Rex begonias do well in bright indirect light.

Here’s an easy way to check the light in your area: Place your hand about two inches from the wall near the light source where you would place your begonia. If your hand casts a soft shadow, it means the place receives bright indirect light. On the contrary, if the tone is dark and well defined, the light you receive is too direct and perhaps too intense for this plant.

A begonia that receives too much light will show signs of dry, discolored leaves. In the worst case, the leaves can even become brittle and dry out. If this happens, move the plant away from the light source. This should fix the problem with the new sheets, but unfortunately there is no way to fix the sheets that have already been bleached. You can either remove those unsightly leaves or wait for the plant to shed them.

Do begonias need a lot of humidity?

We don’t have much control over humidity when growing begonias in the garden. However, it’s a different story when we grow begonias as a houseplant.

Begonias like a humid environment (about forty percent humidity) and some begonias can only be grown in greenhouses. Always check the nursery label before buying a begonia to keep as a houseplant.

The rhizomatous begonia ‘Glaziovii’ needs a lot of humidity.

The paradox, however, is that begonias don’t like wet leaves. Begonias are very susceptible to powdery mildew, so avoid the temptation to spray them.

The best way to increase the humidity of this plant is to place it in naturally more humid places, such as the kitchen or the bathroom. Another good way is to place it in a pebble tray that you have filled with water. The pebbles (or marbles) form a barrier between the roots and the water, while moistening the air around the plant as the water evaporates.

During the winter, you should place your begonias away from radiators and heat sinks. In the summer, do not place it in direct drafts or next to fans or air conditioners.

What type of pot do I need for my begonia?

The answer to this question depends on the size of your plant and your plant care tendencies. If you know you’re a water addict and can’t resist pouring water into the pot at the first sign of thirst, then it’s best to choose an earthenware pot.

If you plant your begonia in a terracotta pot, you will need to water it more frequently.

Porous terracotta allows excess water to evaporate and (usually) protects your plant from trouble. The thickness of the terracotta pots also protects the roots from rapid temperature fluctuations and allows better aeration of the soil.

Keep in mind, however, that begonias are thirsty houseplants, so the benefits of terracotta can be counterproductive if you lean more towards water.

Ceramic pots are the best option in this case. The glaze on ceramic pots helps keep moisture in the soil longer, so although it looks like a terracotta pot inside, it does not allow water to evaporate quickly. Some ceramic pots don’t have drainage holes, so be sure to only use them as decorative pots for well-drained plastic pots.

Begonia Rex ‘Maui Sunset’ in a ceramic pot

Speaking of plastic pots, they are always a good option for moisture-loving plants. They’re lightweight and hard to break, and they come in a variety of colors, so it’s easy to find something that matches your decor. All store-bought plants come in plastic pots, so chances are you already have a stock of pots ready to transplant your begonia.

Plastic pots are a good option for indoor begonias.

No matter what type of pot you choose for your indoor begonia, drainage holes are non-negotiable.

When should I transplant my indoor begonia?

If you think your begonia has outgrown its current home, it may be time to upgrade it. Some signs of a begonia in need of transplanting include roots sticking out of drainage holes, needing to be watered more often than usual, and dealing with extremely compacted soil.

It may be time to transplant that rex begonia.

When expanding your begonia’s pot, be sure to choose a container about two inches in diameter larger than the one you are replacing. You want the plant to have enough room to grow without having to deal with excess wet soil. Slow, gradual increases in size are essential for proper pot sizing.

Waiting to transplant until spring or summer, when the plant is most vigorous, will allow the begonia to recover and adjust to its new home without too much disturbance.

As you can see, growing begonias indoors isn’t difficult, especially if you’re willing to change up your environment a bit.

Begonias are beautiful houseplants that reward you with long-lasting blooms in warm colors, even in the dead of winter. For me, it is worth growing begonias as houseplants!