How to Grow and Care for Begonias Indoors

The begonia genus represents a vast and diverse group of plants, cherished by indoor gardeners for their ornamental qualities. Native to tropical and subtropical regions, these plants have been cultivated to produce thousands of hybrids and cultivars. Their appeal often comes from either their striking, patterned foliage or their delicate flowers, making them a popular choice for adding visual interest to home interiors.

Common Types of Indoor Begonias

Understanding the specific type of begonia you have is the first step toward providing appropriate care, as the genus is categorized into distinct groups based on their root systems and growth habits. Fibrous and rhizomatous types are better suited for indoor cultivation than tuberous varieties, which are more commonly grown outdoors. Knowing which group a plant belongs to provides a foundational context for its long-term health.

Cane begonias are distinguished by their upright, bamboo-like stems with noticeable joints or nodes. This group, which includes popular “Angel Wing” varieties, is grown for both its attractive, often spotted, wing-shaped leaves and its clusters of hanging flowers. These plants can grow quite tall over time but respond well to pruning to maintain a compact shape. Their woody stems give them a shrub-like appearance as they mature.

Rhizomatous begonias are prized primarily for their dramatic and varied foliage. These plants grow from a thick, fleshy stem called a rhizome that creeps along the surface of the soil, with leaves and roots emerging directly from it. This category includes a vast number of cultivars with diverse leaf shapes, textures, and colors, such as the “Iron Cross” begonia (Begonia masoniana).

A specific subgroup of rhizomatous begonias, Rex begonias (Begonia rex-cultorum), are often placed in their own category due to their exceptionally showy leaves. The foliage of Rex varieties features spectacular combinations of color, including shades of green, pink, red, silver, and purple, often in metallic or iridescent patterns. While their flowers are less significant than their leaves, their main appeal is their ornamental foliage. These types are known to appreciate higher levels of humidity.

Wax begonias (Begonia semperflorens-cultorum) are commonly seen in outdoor garden beds but can also be grown as indoor houseplants. These are fibrous-rooted plants known for their fleshy, waxy leaves and continuous production of small white, pink, or red flowers. When brought indoors, they can provide color throughout the year if given sufficient bright, indirect light. Their compact growth habit makes them a good fit for smaller pots.

Essential Care Requirements

Light

Most indoor begonia varieties thrive in bright, indirect light. An ideal location is near an east-facing window that receives gentle morning sun, or several feet back from a more intense south- or west-facing window. Direct, harsh sunlight can scorch the leaves, causing them to bleach or develop burnt spots. If a plant’s shadow appears dark and sharply defined, the light is likely too intense.

Water

The best approach is to water thoroughly only when the top inch of the soil feels dry to the touch. Overwatering is a common issue and can lead to root rot, a condition from which these plants rarely recover. It is better to underwater slightly than to keep the soil constantly saturated. Always ensure pots have adequate drainage holes and that any excess water is emptied from the saucer.

Soil

The growing medium for indoor begonias should be light, airy, and well-draining to prevent waterlogging. A standard, all-purpose potting mix can be improved by adding components like perlite or orchid bark to increase aeration and drainage. Heavy, dense soils retain too much moisture and can lead to the decay of the root system.

Temperature and Humidity

Most begonias prefer the stable temperatures found in a typical home, between 65 and 75°F. They are sensitive to drafts and sudden temperature fluctuations, so they should be kept away from open windows and air vents. Many popular indoor types flourish in high humidity, ideally around 50% or higher. To increase ambient moisture, you can group plants together, place the pot on a tray of pebbles and water, or use a room humidifier.

Fertilizer

During the active growing season of spring and summer, begonias benefit from regular feeding. A balanced liquid fertilizer, diluted to half-strength, is suitable for most varieties. This solution should be applied every two to four weeks. As plant growth slows in the fall and winter, fertilization should be reduced or stopped completely to prevent the buildup of salts in the soil.

Pruning and Repotting

Using clean, sharp scissors or pruners, you can trim back stems that have become long and sparse. Making cuts just above a leaf node will stimulate new branches to emerge from that point, resulting in a bushier plant. Removing any dead or yellowing leaves, as well as spent flowers, helps redirect the plant’s energy toward new growth and reduces the risk of disease.

Repotting should be considered when a begonia shows signs of being root-bound, such as roots growing out of the drainage holes or a noticeable slowdown in growth. Begonias perform well when their roots are slightly snug in their container. When you do repot in the spring, select a new pot that is only one to two inches larger in diameter than the current one. This prevents the plant from sitting in an excessive volume of soil that can stay wet for too long.

When moving the plant, gently loosen the root ball to encourage the roots to grow into the new soil. Place the plant in the new pot at the same depth it was previously growing and fill the surrounding space with fresh potting mix. After repotting, water the plant thoroughly to help the soil settle and reduce transplant shock.

Common Problems and Solutions

Powdery mildew appears as white, dusty spots on the leaves and stems. This fungal disease is often a result of poor air circulation and leaves that remain wet for extended periods. To address this, improve airflow around the plant, avoid getting water on the foliage, and apply a fungicide if the problem persists.

When a begonia develops long, sparse stems with few leaves, it is a condition known as leggy growth. This indicates that the plant is not receiving enough light and is stretching toward the nearest light source. The solution is to move the plant to a brighter location and prune the leggy stems to promote a fuller habit.

Crispy, brown edges on the leaves are a symptom of low humidity. The dry air causes the leaf tissue to lose moisture faster than the roots can absorb it. To remedy this, increase the ambient humidity by using a pebble tray, grouping plants together, or operating a humidifier nearby.

Yellowing leaves that eventually drop from the plant are most often a sign of overwatering. When the soil is kept too wet, the roots are unable to function properly, leading to stress that manifests as yellow foliage. Check the soil moisture before watering again, and allow the top inch or more to dry out completely.