Begonias are one genus, but they do not share one care routine. NC State Extension counts more than 2,100 species, and growers sort them into informal groups by how they grow: from canes, creeping rhizomes, tubers or fibrous roots. The group tells you how much light the plant wants, how dry it can get, and what happens in winter.
Identify the group first. Then copy care advice written for that group, not for “begonias” in general.
The six begonia groups at a glance
| Group | How to recognise it | Examples | Grown for | Main care difference |
|---|---|---|---|---|
| Cane | Upright, bamboo-like stems with swollen nodes; often loses lower leaves | Begonia maculata (polka dot), angel wing, ‘Lucerna’ | Spotted “angel wing” leaves and hanging flower clusters | Good light but no direct sun; stem cuttings; pinch to keep bushy |
| Rex | Large, metallic, multi-coloured leaves from a short rhizome | B. rex hybrids such as ‘Escargot’, ‘Curly Fireflush’ | Foliage | Highest humidity need; keep leaves and crown dry |
| Other rhizomatous | Thick stem creeping along the soil surface; leaves rise from it | B. masoniana (iron cross), B. bowerae (eyelash), B. cleopatrae | Patterned, textured leaves | Most tolerate about 50% humidity; let the surface dry in winter |
| Tuberous | Grows from a tuber; dies back each year | B. × tuberhybrida, B. boliviensis | Large single or double flowers | Summer plant with a winter dormancy; not a year-round houseplant |
| Wax (semperflorens) | Small, mounded, fleshy stems, glossy green or bronze leaves | ’Ambassador’, ‘Cocktail’, ‘Senator Deep Rose’ | Constant small flowers | Mostly bedding; bronze leaves take more sun |
| Rieger / Elatior (semi-tuberous) | Compact pot plant in full flower, often sold in winter | B. × hiemalis cultivars | Flowers | Short-term flowering plant; cool while in bloom |
Sources: NC State Extension group profiles, the RHS houseplant guide and Clemson HGIC 1552.
Cane begonias, including Begonia maculata
NC State describes cane begonias as upright, usually unbranched stems with thickened nodes that resemble bamboo. Kept in check they stay 30–60 cm (1–2 ft) tall, but some reach 3 m (10 ft). Most come from Brazil.
How to spot one: jointed stems, asymmetrical “angel wing” leaves, and flowers in hanging clusters at the stem tips. Begonia maculata, the polka dot begonia, grows 60–90 cm (2–3 ft) with dark green leaves spotted grey to silver and orange-red undersides. The RHS lists ‘Lucerna’ as a strong cane with silver-spotted olive leaves and pink flowers.
Care that differs:
- Light: the RHS says cane types need good light for sturdy stems and flowers, but no direct sun. Clemson notes that angel wing leaves lose their spots and scorch in too much sun.
- Temperature: best at 15–22 °C (58–72 °F), per the RHS.
- Water: do not let the compost dry out completely, avoid overwatering, and water less in winter.
- Shape: NC State recommends pinching the tips to promote new growth and keep the plant contained.
- Propagation: stem cuttings are the easiest method. Hybrids do not come true from seed.
For the polka dot begonia specifically, see Begonia maculata watering, humidity and propagation.
Rex begonias
Rex begonias are hybrids of Begonia rex, a species from Bhutan to northern Myanmar that entered cultivation in the 1850s. NC State calls them painted-leaf or fancy-leaf begonias. They grow 30–45 cm (12–18 in) tall, with leaves in green, red, pink, silver, grey, lavender and maroon. The small flowers matter little.
They are the hardest group to keep indoors. NC State’s genus profile says rex begonias need humidity above 75% and decline if it is too low; Missouri Botanical Garden gives more than 50%, with some cultivars wanting more. Both agree on the method: raise humidity around the plant, but do not mist.
- Light: bright, indirect light. No hot, direct sun.
- Water: Missouri Botanical Garden says to let the surface become almost dry between waterings. The RHS says never wet the leaves or the crown.
- Temperature: around 21 °C (70 °F) by day and 16 °C (60 °F) at night (Missouri Botanical Garden). The RHS gives a winter minimum of 13 °C (55 °F).
- Winter: many cultivars go dormant and may drop leaves unless grown under lights. Water sparingly until new leaves appear in spring.
Rex begonias root from leaf cuttings. Follow our rex leaf-vein propagation guide. If edges are browning, see rex begonia crispy leaves.
Other rhizomatous begonias
These grow from a rhizome, a horizontal stem that creeps across the soil surface. NC State notes the rhizome stores water and nutrients, which helps these plants survive more readily than other types. Leaves are often heavily textured; star-shaped ones are sold as “star begonias”.
Species NC State lists include B. bowerae (eyelash begonia), B. cleopatrae, B. manicata and B. masoniana. Missouri Botanical Garden describes B. masoniana, the iron cross begonia, as up to 45 cm (18 in) tall, with puckered leaves to 20 cm (8 in) marked by a chocolate-brown cross.
Care sits between cane and rex. NC State says most tolerate 50% humidity and prefer partial or dappled shade. The RHS advice for rhizomatous types:
- Keep them shaded in summer and water freely, with good drainage.
- In winter, let the compost surface dry before watering again.
- Keep at least 10 °C (50 °F) in winter, or 13 °C (55 °F) for B. bowerae, B. masoniana and B. rex.
When the rhizome grows over the pot edge, cut it back. The RHS says to divide rhizomatous begonias in spring so each piece has a growing point.
Tuberous begonias
Tuberous begonias grow from a tuber and are grown for flowers about 7.5 cm (3 in) across, single or double. NC State describes a bushy, weeping or cascading habit, 30–60 cm (1–2 ft) tall, flowering for about four months from early summer to frost. They dislike heat, high humidity and drought.
They are summer plants. University of Minnesota Extension notes they enter a dormant period however they are grown, so they are not suitable as year-round houseplants. Reduce watering when leaves yellow in autumn, then store the tubers dry and frost-free.
Trailing tuberous types are the classic basket begonias. See our begonias for hanging baskets guide.
Wax begonias
Wax, or semperflorens, begonias are hybrids derived from Begonia cucullata. NC State describes them as compact and fibrous-rooted, 15–30 cm (6–12 in) tall, with fleshy stems and green to bronze leaves. They flower from spring to frost.
They are mainly bedding plants. Clemson and NC State both note that bronze-leaved forms cope better with sun than green ones. Container plants can be cut back in autumn and overwintered indoors in a cool spot with less water.
Rieger and Elatior begonias
The RHS places these in a semi-tuberous group: cultivars of Begonia × hiemalis, a cross between B. socotrana and tuberous begonias. They are mostly winter-flowering florist’s plants, now sold year-round.
The RHS says they are not intended for long-term cultivation and are often discarded after flowering. While in bloom, keep them in semi-shade, evenly moist and at 10–13 °C (50–55 °F). Clemson HGIC 1552 says a Rieger can be restarted by cutting it back to within 7.5 cm (3 in) of the crown.
Care that applies to every group
- Light: Clemson HGIC 1552 puts flowering begonias in a bright spot with some early morning sun, such as an east window. Foliage begonias get bright light away from direct sun.
- Water: keep the mix evenly moist and let it dry only slightly between waterings (Clemson). Reduce watering in winter.
- Air: the RHS warns against misting, because begonia mildew thrives in damp, still air. Use a gravel tray instead. If you see white patches, read begonia powdery mildew.
- Feeding: half-strength balanced liquid fertiliser at alternate waterings during active growth (Clemson).
The RHS links common symptoms to causes. Brown leaf edges suggest low humidity or heat. Rotting leaves and leaf drop suggest overwatering, stagnant humid air or low light. For collapsing stems, check the roots with our begonia root rot guide. For leaf curl, see begonia curling leaves.
Pets
The ASPCA lists all Begonia species, including rex begonia, as toxic to dogs, cats and horses. The toxin is soluble calcium oxalate. Signs in dogs and cats include vomiting and salivation, and the underground parts are the most toxic. NC State adds that the sap can irritate skin. Keep begonias out of reach, and keep tubers away from pets during storage.
More begonia guides: the begonia plant profile and crispy begonia leaves.
References
- NC State Extension Gardener Plant Toolbox: Begonia, Begonia – Cane Types, Begonia – Rex Types, Begonia – Rhizomatous Types, Begonia – Tuberous Types, Begonia – Wax Types
- Royal Horticultural Society: Begonias: houseplants
- Clemson Cooperative Extension, HGIC 1552: Growing Begonias Indoors
- Missouri Botanical Garden Plant Finder: Begonia rex-cultorum, Begonia masoniana
- University of Minnesota Extension: Growing tuberous begonias
- ASPCA Animal Poison Control Center: Begonia, Rex Begonia