Rex Begonia
Grown for leaves, not flowers: big, asymmetric, textured leaves in silver, purple, red, pink, green and near-black, often in spirals and swirls. Wants humidity, filtered light and careful watering, and rewards it with foliage nothing else matches.
Rex begonias are grown for their leaves the way orchids are grown for their flowers. Each leaf is large, lopsided, often puckered or hairy, and painted in combinations of silver, purple, pink, red, green and black that look designed rather than grown. Some spiral at the base into a snail shell. Hundreds of named varieties exist and they all share one set of needs.
Those needs are moderate humidity, filtered light, warmth, and water at the roots rather than on the leaves. They are not hard once you stop treating them like ordinary begonias. They can go semi-dormant and drop leaves in winter; they come back in spring from the rhizome.
Light
Medium to bright, indirect light. An east window is ideal; a north window works; a west or south window needs a sheer curtain. Direct sun scorches and fades the colours. In too little light the colours dull and the stems stretch.
Water
Water when the top inch is dry, every five days or so in summer and every nine in winter, at the soil or from below. Keep the leaves dry; water sitting on them invites mildew and rot. Never let it sit in water; the rhizome rots quickly. In winter, when it slows down, water less.
Soil and potting
A light, airy mix: potting soil with a third perlite and some coco coir. Shallow pot with drainage, since the rhizome creeps across the surface. Repot yearly in spring, one size up, keeping the rhizome at the surface.
Feeding
Quarter-strength balanced feed every three weeks in spring and summer. Skip winter.
Propagation
Leaf cuttings, which is a good party trick. Lay a leaf on damp mix, cut across the main veins, pin it down, and plantlets grow from the cuts in six to eight weeks. Rhizome sections with a leaf also root.
In a hot, dry home
Needs help. It wants fifty percent humidity, so a pebble tray, a plant group, or a humidifier through summer. It also wants to be cool rather than hot, so the interior rooms suit it better than a sunny one. Keep it far from vents. Water at the soil with filtered water and expect a rest in the hottest weeks.
Rex Begonia varieties
Same care, different look. These are the named forms you will see for sale.
- Escargot
Silver and green leaves spiralling into a snail shell at the base. The most famous rex.
- Silver Jewel
Puckered silver leaves with dark green veins.
- Frosty
Silver-white leaves with a thin green edge.
- Iron Cross
Begonia masoniana: puckered green leaves with a dark brown cross. A close relative with the same care.
- Soli-Mutata
Begonia soli-mutata: textured green leaves that shift toward bronze in bright light. Same care.
- Listada
Begonia listada: velvety dark green leaves with a lime central stripe.
- Striped
Silver and dark green banded leaves.
Problems and fixes
White powder on the leaves
Likely cause: Powdery mildew, from wet leaves or stagnant air
Fix: Remove affected leaves, improve airflow, keep water off the foliage.
Brown, crispy edges
Likely cause: Dry air
Fix: Raise humidity.
Leaves dropping in winter
Likely cause: Normal semi-dormancy
Fix: Water less and wait; it regrows in spring.
Rhizome soft and dark
Likely cause: Overwatering
Fix: Cut away the rot, repot the healthy sections, water less.
Rex Begonia questions
Is rex begonia safe for pets?
No. Begonias contain calcium oxalates, concentrated in the rhizome, that cause vomiting and drooling if chewed.
Why did it lose its leaves in winter?
Rex begonias often go semi-dormant in winter. Water less and keep it warm; it regrows from the rhizome in spring.
Can I mist it?
No. Wet leaves get mildew. Raise humidity with a pebble tray or humidifier instead.
Plants with a similar rhythm
Angel Wing Begonia
- Light
- Medium to bright indirect
- Water
- Weekly
- Pets
- Toxic
