At a glance
- Light
- Medium / indirect light
- Typical interval
- Every 6 to 8 days (summer)
Every 11 to 17 days (winter) - Climate
- 18–24 °C
- Humidity
- 50–70 %
- Pet safety
- Toxic to cats and dogs
- Scientific name
- Begonia rex
When and how much water
Water Rex begonia when the top 3 cm of soil feel dry to the touch. In summer that’s typically every 6 to 8 days. In winter, slow down to every 11 to 17 days. Use room-temperature water and let any excess drain. Never leave the pot sitting in standing water.
Adjust the timing for the light at the plant, the pot’s size and material, and the humidity indoors. Terracotta dries faster than glazed ceramic.
Light and placement
Rex begonia thrives in bright, indirect light. Direct midday sun can scorch the leaves. Place it 1–2 meters back from an east or west window, or behind a sheer curtain on a south window.
Feeding
Feed Rex begonia every 30 days while it’s actively growing. Use a balanced liquid houseplant fertilizer at half the strength on the label, and only on soil that’s already damp. Feeding dry roots can scorch them.
When growth pauses, skip the fertilizer and let it rest.
Temperature & humidity
Rex begonia is comfortable between 18 and 24 °C. Below 15 °C the leaves start taking damage, so keep it clear of cold drafts and unheated rooms.
It does best at 50–70% humidity. It doesn’t need misting.
Common problems
Yellowing, drooping, and dry edges often point to watering or drainage. Compare the signs before changing the routine.
Find what’s wrong
Toxic to pets?
Yes. Keep it out of reach.
Pet-safety information in the JungleBook uses ASPCA reference data where available. It is reference information, not veterinary advice.
Full Rex begonia toxicity guide →
Pet-safe alternatives with similar light
Common questions
How often should I water a Rex begonia?
Water your Rex begonia (Begonia rex) when the top 3 cm of soil feel dry to the touch. In summer, that’s typically every 6 to 8 days. In winter, slow down to every 11 to 17 days.
How much light does a Rex begonia need?
Rex begonia thrives in bright, indirect light. Direct midday sun can scorch the leaves. Place it 1–2 meters back from an east or west window, or behind a sheer curtain on a south window.
Is Rex begonia safe for cats and dogs?
The plant contains soluble calcium oxalates. Chewing it can cause oral irritation, drooling, and vomiting. Keep Rex begonia out of reach of pets, or pick a non-toxic alternative like spider plant, moth orchid, Boston fern, or Kentia palm.
Why are my Rex begonia’s leaves turning yellow or drooping?
On a Rex begonia, yellowing and soft growth usually mean overwatering: watch for yellowing leaves, mushy rhizome, or root rot. Let the soil dry further between waterings and check drainage. If you see crispy leaf edges, curling leaves, or faded leaf color instead, it’s likely thirsty. Water a little more often. With Botanicaly Pro, Botanicaly Bot can help assess visible signs from a photo and suggest possible causes.
Sources5 references
- Royal Botanic Gardens, Kew: Plants of the World OnlineAccepted name and taxonomic record
- Royal Horticultural SocietyRex and other rhizomatous begonia care · problems · propagation · Plant profile · growing conditions · cultivation · pests
- North Carolina State University Extension Gardener Plant ToolboxDescription · cultural conditions · insects, diseases, and other plant problems
- University of Florida IFAS ExtensionCultivation Management · Growing Temperature · Potting Medium and Irrigation · Light · Fertilizer · Pests and Disease
- ASPCA Animal Poison ControlScientific name · toxicity · toxic principles · clinical signs
Last reviewed: 2026-09-21
