Houseplants · Guide

Begonia x corallina

Begonia x corallina (Coral Begonia) Care Guide

Updated by Funfactorium Editorial1 min readFact-checked
Photo: Photo by David J. Stang · CC BY-SA 4.0
In short

Begonia x corallina, sold as Coral Begonia, belongs to the cane-stemmed group of Begonia and is grown indoors for its patterned foliage. An older horticultural hybrid involving B. coccinea, with white-spotted green leaves and pendant clusters of coral-red flowers, often called 'Lucerna' in trade. Begonia thrive in bright filtered light, even moisture, and humidity above 50 percent, but they will not tolerate wet leaves overnight or stagnant air.

Care facts at a glance

Light
Bright indirect
Water
Water when the top 2 cm of mix has dried.
Humidity
50–70 %
Temperature
16–24 °C
Soil
Free-draining peat-based mix with extra perlite for aeration.
Toxicity
Mildly toxic if ingested. Tubers and below-ground parts contain soluble calcium oxalates. (humans) · Toxic to cats and dogs per ASPCA. Ingestion can cause kidney irritation and oral burning. (pets)
Origin
Tropical and subtropical regions of the Americas, Africa, and Asia.
Mature size
20 to 60 cm tall depending on type, similar spread.

Overview

Begonia x corallina is one of more than 2,000 species in Begonia, the sixth-largest plant genus. An older horticultural hybrid involving B. coccinea, with white-spotted green leaves and pendant clusters of coral-red flowers, often called 'Lucerna' in trade. Begonia are divided horticulturally into rhizomatous, cane-stemmed, tuberous, and rex groups; this species belongs to the cane-stemmed group.

Care Priorities

  • Bright filtered light, never direct midday sun.
  • Water at soil level when the top 2 cm of soil dries.
  • Humidity above 50 percent — group with other plants or use a pebble tray.
  • Good air circulation prevents powdery mildew and botrytis.
  • Pinch growing tips on cane Begonia to encourage branching.

Common Problems

White powdery patches on leaves are powdery mildew — improve air flow and remove affected leaves immediately. Grey fuzzy patches are botrytis — reduce humidity and never water late in the day. Brown crispy edges signal dry air or under-watering.

Sources & further reading (3)
  1. encyclopedia — accessed 2026-04-28
  2. botanical-garden — accessed 2026-04-28
  3. toxicity-database — accessed 2026-04-28

Frequently asked questions

Is 'Lucerna' the same as Begonia x corallina?

'Lucerna' is the most popular cultivar of B. x corallina, with denser silver spotting and a more upright habit. The two names are often used interchangeably at retail.

How do I propagate a Begonia from a leaf?

Cut a healthy mature leaf with a section of petiole, slice the major veins on the underside, and lay the leaf flat on moist sphagnum or potting mix. New plantlets emerge from the cut veins within 4 to 8 weeks under high humidity.

Is Begonia toxic to pets?

Yes — Begonia is listed as toxic to cats and dogs by the ASPCA. The tubers (in tuberous types) are the most concentrated source of toxic calcium oxalates. Keep out of reach of pets that chew plants.

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