Rex Begonia problems & how to fix them
Begonia rex
Drooping, yellowing, brown tips, or a plant that just won’t thrive? Here are the most common Rex Begonia problems, what usually causes them, and how to turn things around.
Common problems
Powdery mildew
The signature rex problem — white patches bloom in humid, stagnant air. A fungal disease that coats leaves in a white, powdery film and slowly weakens the plant. Caught early and treated consistently, most plants recover fully within a few weeks.
powdery mildew's white coating on leaves
Photo: Dmitry Brant · CC BY-SA 4.0 · Wikimedia Commons
Root rot
The shallow rhizome rots fast in dense, wet mixes; shallow pots help. A fungal or bacterial infection of the roots, almost always triggered by soil staying wet too long. Caught early, most plants recover within a few weeks after repotting; if most roots are already mushy, recovery is uncertain.
Phytophthora root rot on a dug-up root ball
Photo: Jerzy Opioła · CC BY-SA 4.0 · Wikimedia Commons
Fungal leaf spot
Water sitting on the textured leaves triggers spotting and botrytis. A fungal infection that creates dark spots inside leaf tissue, often with yellow halos, and spreads through water splash on wet leaves. Existing spots will not heal, but with pruning and drier foliage the spread usually stops within two to three weeks.
Cercospora leaf spots with dark rims on a spinach leaf
Photo: Plant pests and diseases · CC0 · Wikimedia Commons
Crispy tips (low humidity)
Dry heated air crisps the ornate leaf edges. Brown, dry leaf tips caused by air that is too dry for the plant, common in heated or air-conditioned rooms. Existing crispy tips never turn green again, but with higher humidity new growth should come in clean within a few weeks.
The mistakes that most often kill it
- Misting or splashing the foliage, which invites mildew and rot.
- Deep pots with heavy soil around the shallow rhizome.
- Tossing it during its winter rest — the rhizome is usually still alive.
Not sure what’s wrong?
Ploomily’s rescue tool walks you through the symptoms, gives an honest diagnosis, and schedules a day-by-day recovery plan. The founding price in force today is shown in full before you confirm, and locked for as long as you stay subscribed — with 30 days to change your mind.
Rescue my plant