Begonia care

Light

Begonia thrives in bright indirect light — the conditions just back from a sunny window, with plenty of ambient brightness but rarely any direct rays on the leaves themselves. Part shade to morning sun; tolerates fuller sun in cooler climates. If you are not sure whether your spot is bright enough, a free phone lux-meter app at midday is the quickest way to check; aim for 800-1,500 lux.

Watering

Water begonia weekly watering. The actual day count varies with pot size, light level, and the season — the finger test (or, better, lifting the pot to feel its weight) is more reliable than a calendar. Empty any drainage saucer after watering so the pot is never sitting in water. Consistent moisture; let dry slightly between waterings.

Soil and pot

Begonia grows best in rich free-draining loam. pH 5.5-6.5. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Begonia sits happiest at around 50-60% humidity and 15-24°C (60-75°F). Average household humidity is fine. If you keep the room above 15 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed begonia sparingly. Half-strength balanced feed every 3-4 weeks during flowering. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on begonia in the Growli community. Each is annotated with the most common cause so you know where to start.

• Powdery mildew — Improve air flow; treat with fungicidal soap.
• Yellow lower leaves — Overwatering or root-bound.
• Few flowers — Too much shade or under-feeding.
• Soft black stem base — Botrytis rot; remove and improve air flow.
• Wilting in heat — Hot afternoon sun; move to part shade.

Companion plants

Begonia pairs well with Impatiens, Coleus, and Sweet alyssum. These are species with similar light and water needs, so you can group them in the same room or on the same shelf and water as a batch.

Propagation

Stem cuttings root in water; or sow tiny seed indoors very early. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Begonia is mildly toxic to pets. ASPCA lists Begonia species as toxic to cats and dogs due to soluble calcium oxalates, especially in the tubers. Causes oral irritation and vomiting. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Begonia deep-dive guides

Every aspect of begonia care, each with its own calibrated guide:

• Begonia watering schedule
• Begonia light requirements
• Best soil mix for begonia
• Begonia fertilizing guide
• When to repot begonia
• How to propagate begonia
• Begonia growth rate & size
• Begonia cold hardiness
• Begonia temperature & humidity
• Is begonia toxic to cats & dogs?
• Getting begonia to bloom

Related guides

Begonia is also known as wax begonia, bedding begonia, and fibrous begonia.

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