Begonias

How to choose begonias

Most of this range descends from Begonia rex, a rhizomatous species bred for foliage. Begonia Escargot is the most widely grown: each leaf curls into a spiral at the base like a snail shell, banded in silver and olive green. Begonia rex Kotobuki is a classic patterned rex for a tabletop pot. The Beleaf series were bred as sturdier house plants with thicker leaves; Beleaf Inca Night Begonia gives dark, dramatic foliage and Beleaf Arctic Breeze Begonia is a pale, silvery contrast to it. Maori Haze Begonia adds another colourway.

Group two or three contrasting leaf patterns together; they share the same needs and look stronger as a set than alone. All grow to roughly 30cm to 40cm high and wide.

Where begonias grow

Indoors, give rex begonias bright, indirect light: near an east or south facing window, or back from a north one. Direct sun bleaches and scorches the leaves, and deep gloom makes them leggy and dull. They like the same temperatures people do, and they dislike cold draughts and dry air from heaters and air conditioners.

Outdoors they suit sheltered, shaded spots in frost-free areas: a covered verandah, a fernery, or under trees in Sydney, Brisbane and the tropics. Frost kills the foliage, so in cold districts keep them as house plants. Begonias are toxic to cats and dogs if chewed, with the underground parts the most harmful, so place them out of reach of pets. Browse more indoor plants for the same rooms, or the plants for full shade for outdoor companions.

Planting and spacing

Rex begonias have shallow rhizomes that creep across the surface, so a wide, shallow pot suits them better than a deep one. Use a free-draining indoor potting mix, with extra perlite or fine bark if it seems heavy, and never bury the rhizome. Only move up one pot size at a time, as begonias sulk in a large volume of wet mix. In shaded beds, space plants 30cm apart in soil lightened with compost.

Care basics

Overwatering is what kills most begonias. Water when the top 2cm to 3cm of mix is dry, tip out any water left in the saucer, and water less in winter when growth slows. Water the mix, not the leaves, because wet foliage and still air bring on powdery mildew and leaf spot. Raise humidity by grouping plants or standing pots on a tray of wet pebbles instead of misting. Feed with a half strength liquid fertiliser monthly from spring to autumn. Remove old leaves at the base. Some rex begonias rest in winter and drop a few leaves; keep them just moist and they reshoot in spring. New plants strike readily from leaf cuttings.

Common questions

Are begonias indoor or outdoor plants?

Both. Rex and foliage begonias are grown indoors in most of Australia, and outdoors in sheltered shade where there is no frost.

Are begonias toxic to pets?

Yes. Begonias are toxic to cats and dogs if chewed, particularly the rhizomes and roots. Keep them where pets cannot reach.

Why are my begonia leaves going crisp at the edges?

Usually dry air, direct sun or irregular watering. Move the plant out of sun and away from heaters, and raise the humidity around it.

Do rex begonias flower?

Yes, with small pink or white flowers, but the foliage is the feature. Many growers pinch the flowers off to keep energy in the leaves.