Polka dot begonia

Foliage and growth habit

This species is recognizable by its contrasting leaves: the dark green upper surface is covered in silvery spots, while the underside is red. The leaves are elongated, asymmetrical, and up to 20 cm long.

The plant grows upright, with fleshy stems and a fibrous root system. Indoors, a mature plant usually reaches 60-90 cm tall and 30-45 cm wide; long stems may trail.

In everyday use and in the plant trade, this species is often called by the Ukrainian name meaning “begonia with polka dots,” or polka dot begonia, for the silvery spots on its leaves. The Ukrainian equivalent of Begonia comes from the Latin genus name, which honors Michel Bégon.

Origin and natural habitat

This species is native to southeastern Brazil. In the wild, it grows in tropical forests, where light filters through the tree canopy rather than striking the leaves as direct midday sun.

This background explains its needs indoors: the plant needs a bright spot but is sensitive to overheating and drying of the leaves. Its roots are not adapted to waterlogging, so high humidity does not mean the potting mix should stay constantly wet.

Light and placement

Bright indirect light is ideal. At an east-facing window, the plant gets enough light without prolonged overheating; at a south-facing window, it needs shade from direct sun.

If light is insufficient, the stems become leggy and the spots on the leaves look less distinct. Too much sun can cause dry, damaged patches on the leaves.

• bright indirect light
• protection from direct midday sun
• a spot free of cold drafts

Consider the season when placing the plant right next to window glass: it can be cold there in winter, while in summer the leaves can quickly overheat.

Watering, humidity, and potting mix

Water when the top 2-3 cm of potting mix is dry. Two extremes are harmful to this species: prolonged dryness weakens the leaves, while constant wetness around the roots increases the risk of rot.

The potting mix should be light, slightly acidic, and well-drained. An African violet mix with peat, perlite, and vermiculite is suitable, as is another airy potting mix for foliage plants.

A tray of damp pebbles or a humidifier helps maintain humidity, but the bottom of the pot must not sit in water.

Pruning and propagation

The stems lengthen with age, so shape the plant by pruning or pinching. In spring, remove weak and overly long stems to encourage branching from the leaf axils.

The plant is most often propagated by stem cuttings. Choose a strong stem with 2-3 nodes, cut below a node, and root it in water or in moist, well-drained potting mix.

• a healthy stem without blemishes or rot
• 2-3 nodes per cutting
• bright indirect light
• moderately moist potting mix
• ventilation under the cover

Spring or early summer is the best time to take cuttings. At +22…+25 °C, roots usually develop faster, but excessive moisture under the cover can cause rot.

Flowering and seasonal growth

Indoors, the plant may produce small pinkish-white flowers on pinkish-red stems. It flowers from spring to fall, most actively during the warmer part of the year.

Growth slows in fall and winter, so reduce feeding. During active growth, apply fertilizer every 2-3 weeks at half strength.

Problems and pet safety

Yellowing, soft stems, and an unpleasant smell from the potting mix are most often linked to overwatering and poor drainage. Dry, pale patches on the leaves usually appear after exposure to direct sun or overheating near window glass.

Possible pests include whiteflies, spider mites, and aphids. Isolate the plant, rinse the leaves with water, and remove pests by hand or with a soap solution.

This species is mildly toxic to cats and dogs. Begonia sap contains substances that can irritate mucous membranes when chewed, so it is best to keep the pot out of pets’ reach.