How to Care for Begonia

October 1, 2026

Time to read 4 min

Begonia is one of the largest plant genera on earth, and the variety is extraordinary. The rex begonias grown as houseplants have leaves that look painted: swirls of silver, burgundy, plum and near-black, often with a metallic sheen and a spiral at the base of each leaf. Others are grown for their polka-dotted foliage, their fine silver hairs, or their clusters of pink and white flowers. Whatever the type, a Begonia is grown for drama.

There are around two thousand species, spread across the tropics and subtropics of Central and South America, Africa and Asia. The rex types most people buy as houseplants descend from species from northeastern India and the Himalayan foothills. Most grow in damp, shaded, sheltered places on forest floors and rocky slopes, often from a creeping rhizome at the surface rather than deep roots. That shallow, surface rooting habit is the key thing to remember, because it makes them particularly unforgiving of heavy wet compost.

How Much Light Does Begonia Need?

Begonia wants bright, indirect light. A position near an east-facing window, or a metre or so back from a south or west facing one, suits it well.

Light is what brings out the colour. In a bright spot the silvers stay bright and the burgundies deepen, while in a dim corner the same plant fades, the stems stretch and the patterning loses definition. Keep it out of direct sun though, which scorches those thin, often textured leaves very easily and leaves dry bleached patches. If you have a rex begonia with especially dark leaves, err on the brighter side, as they need more light than they look like they do.

How Often Should You Water Begonia?

Water when the top 2 to 3cm of compost feels dry. In spring and summer, that usually means once a week, dropping to every ten to fourteen days in autumn and winter.

Two details matter more with Begonia than with most plants. First, water the compost and not the plant. Wet leaves and a damp crown invite powdery mildew and rot, and Begonia is prone to both, so pour carefully at the edge of the pot and avoid splashing the foliage. Second, err on the dry side. Those shallow rhizomes sit right at the surface and rot quickly in soggy compost.

Water thoroughly until it runs from the drainage holes, then drain the pot fully. A light, open, free-draining mix in a fairly shallow pot suits them far better than a deep pot of dense compost.

What Humidity Does Begonia Need?

Begonia prefers humidity of 50% to 60%, with one important caveat: it wants humid air, not wet leaves.

Its native damp forest habitats provide constantly moist air, and higher humidity gives you larger, better coloured leaves and fewer crispy edges. But because Begonia is susceptible to powdery mildew and leaf spotting, misting is the wrong way to provide it. Use a humidifier, a tray of damp pebbles or a cluster of other plants instead, and make sure there is reasonable air movement around the plant rather than damp stagnant air. A bright bathroom works well provided it is not permanently steamy and still.

What Temperature Does Begonia Need?

Begonia grows best between 18°C and 24°C and likes stable conditions.

The lowest temperature it can withstand is around 13°C, and the rex types are happier kept above 15°C. Below that the leaves develop dark soft patches and drop, and sustained cold combined with damp compost will rot the rhizome. Keep it away from draughts and cold glass in winter. Some rex begonias also go semi-dormant in the colder months, losing a number of leaves and looking rather thin until spring, which is normal rather than a failure.

How Do You Propagate Begonia?

Begonia is one of the most rewarding plants to propagate, because many types will grow an entire new plant from a single leaf.

For a straightforward leaf cutting, remove a healthy leaf with 3 to 4 cm of stalk and push the stalk into damp, free-draining compost so the leaf sits just above the surface. Keep it warm, bright and humid under a clear bag or propagator lid. A small plantlet appears at the base of the stalk within four to eight weeks.

For rex and other rhizomatous types there is a neater trick. Lay a whole leaf face up on damp compost and make several small cuts across the thick veins with a clean blade, then pin the leaf flat against the surface with hairpins. New plantlets form at each cut vein. You can also cut the leaf into triangular wedges, each containing a main vein, and push the pointed end of each wedge into compost.

Stem cuttings work well on the cane and trailing types: take a section with two or three leaves, cut below a node, and root it in water or damp compost.

Why Are My Begonia Leaves Turning Yellow?

Overwatering is the most common cause, and with Begonia it moves quickly. Soft yellow leaves, leaves dropping at a touch, or a rhizome that has gone brown and mushy at the surface all mean the compost has stayed too wet. Stop watering, let the top of the pot dry out properly, and check the drainage. If the rhizome is already rotting, take leaf cuttings from the healthy foliage immediately, because that is often the only part you can rescue.

Look out for powdery mildew too, since it often appears alongside yellowing. It shows as a dusty white coating on the leaves and it thrives in damp, still air. Remove affected leaves, improve air movement around the plant, and stop wetting the foliage.

Check the simpler causes as well. Yellowing with dry, shrunken compost means underwatering, so soak it well. Pale, bleached yellow leaves with dry patches mean too much direct sun. A batch of yellowing after a cold spell means chill damage. Slow general yellowing in the growing season means it is hungry, so feed at half strength every two to four weeks in spring and summer. And older leaves at the base yellowing while new ones unfurl is normal, as is a general thinning out over winter on rex types.

To keep a Begonia looking its best, water at the soil rather than the leaves, keep the air moving, use a shallow pot with free-draining compost, and remove dead leaves promptly so they do not sit and rot against the rhizome.