Plant care guide
Begonia Crispy Leaves: Find the Cause and Stop New Damage
Updated · First published
Why are my Begonia leaves crispy?
Crispy begonia leaves are dead tissue. The usual causes are dry air, a pot that dried out, too much sun or a sudden move into brighter light, and fertilizer salts. Root rot and leaf diseases can cause brown, dying leaves too, so check the mix before you water.
What to do first
Feel the mix, note which side of the plant is damaged, and look for white powder or spreading spots. Water a dry pot from below, shade a sun-scorched plant, flush salt crust, and raise humidity without wetting the leaves.
Crispy, brown begonia leaves are disheartening, and the damaged tissue will not recover. The good news is that the cause is usually something you can change. Where the damage sits and how the mix feels will tell you which one it is.
Begonias are a varied group. NC State Extension’s begonia profile lists wax, tuberous, cane, rhizomatous and Rex types. Their needs differ. Rex begonias, for example, need humidity above 75% and decline when it is too low. If yours is a Rex, see our Rex begonia crispy leaves guide.
Read the pattern
| What you see | Check first |
|---|---|
| Brown, crisp edges on many leaves, heating on | Dry air |
| Crisp or curled leaves, light pot, mix shrunk from the pot edge | Pot dried out |
| Brown or bleached patches on the window side, or after a move | Sun or a sudden light change |
| Brown edges with white crust on the mix or rim, recent feeding | Fertilizer salts |
| Yellowing and wilting in wet mix, soft stems | Root rot |
| White powdery spots, or water-soaked spots turning brown | Leaf disease |
Dry air. Iowa State University Extension’s guide to environmental problems calls low humidity the most common reason for brown leaf tips. Homes are especially dry in winter.
Dry pot. Iowa State also blames inconsistent watering, especially letting plants dry out too long. Virginia Cooperative Extension’s watering guide lists dry or brittle leaves, brown tips or edges, curling, mix shrunk from the pot and a very light pot.
Sun. Iowa State says leaf scorch often follows a quick move into much brighter light. NC State notes that most begonias prefer partial shade.
Salts. Iowa State links excess fertilizer salts to brown leaf edges. University of Missouri Extension’s article on leaf tipburn says a whitish residue on the mix means it needs flushing. It also warns against water from a water softener.
Root rot. NC State warns that begonias are highly susceptible to root rot, so avoid overwatering. UC IPM’s begonia disease table describes Pythium root and stem rot. Roots become small and discoloured, and stems turn water-soaked and collapse.
Leaf disease. UC IPM describes powdery mildew as white, powdery spots on both leaf surfaces. Bacterial leaf spot starts as small, water-soaked, blister-like spots that turn brown.
What to do
Dry air:
- Put a hygrometer by the plant and run a humidifier close to it. UNH Extension’s humidity guide says this gives the most consistent control.
- Move the plant away from heat vents, radiators and outside doors.
- Group plants together, or stand the pot on a pebble tray above the water line.
Do not mist. NC State recommends watering at the base and keeping water off the leaves, because of powdery mildew.
Dry pot:
- Water until the whole root ball is wet. Virginia Cooperative Extension recommends bottom watering for begonias, because they do not tolerate wet foliage.
- Do not leave the pot in the water for more than 60 minutes.
- Check the mix more often from now on. UConn’s Rex begonia factsheet suggests watering when the top 2.5 cm (1 in) feels dry.
Sun:
Move the plant out of direct sun into bright, indirect light. Iowa State advises changing light levels gradually over several weeks.
Salts:
Flush the mix with plain water and let it drain fully. Missouri advises following the fertilizer label and catching drainage water so salts are not wicked back up. It also advises against feeding in winter for plants without supplemental light.
Wet mix or soft stems:
Stop watering and check the roots. Our begonia root rot guide covers the rescue.
Powder or spots:
Keep the leaves dry and give plants space. UC IPM advises increasing air movement for powdery mildew. For bacterial leaf spot, it advises avoiding wet foliage and crowding. See our begonia powdery mildew guide.
Protect the next leaves
Trim fully dead leaves at the stem. Iowa State notes that trimming brown edges only helps temporarily if the cause is still there. Judge your fix by the new leaves.
Keep begonias warm, too. NC State says they do not tolerate temperatures below 13 °C (55 °F).
The begonia types guide explains how care differs between groups. The begonia hub lists our other begonia pages, including curling leaves and dropping leaves.
References
- NC State Extension Gardener Plant Toolbox: Begonia
- Iowa State University Extension: Diagnosing Houseplant Problems from Improper Environmental Conditions
- Virginia Cooperative Extension: Properly Watering Container Houseplants (SPES-804)
- UNH Extension: How can I increase the humidity indoors for my houseplants?
- UC IPM: Begonia diseases (Floriculture and Ornamental Nurseries)
- UConn Home & Garden Education Center: Rex Begonia
- University of Missouri Extension: Leaf Tipburn on Houseplants
How this guide was put together: NC State Extension, Iowa State University Extension, Virginia Cooperative Extension, UNH Extension, UC IPM, UConn Home & Garden Education Center and University of Missouri Extension guidance.