Care problem

Edema

Small corky bumps under the leaves when roots take up more water than the leaves can use.

What you'll see

• Small water-soaked bumps or blisters on the undersides of the leaves.
• The bumps turn white, tan or brown and go corky or scabby.
• Older leaves are hit most, and badly affected leaves yellow and drop.
• Common on geraniums, jade plants, peperomias, succulents, ivy and camellias.

Why it happens

The roots take up more water than the leaves can give off, so leaf cells swell and burst. Wet soil with cool, dull, humid air sets it off.

How to fix it

1. Water less often: let the top of the mix dry, but never let the plant dry out completely.
2. Give more light and better air flow, and never leave the pot standing in water.
3. Leave affected leaves on; the bumps won't heal, but new leaves will grow in clean.

Keep it from coming back

• Match watering to the weather, especially in cool, cloudy spells.
• Space plants for air flow.
• Use free-draining mix in pots with drainage holes.

Read more

• Overwatering vs underwatering

Sources

• Missouri Botanical Garden: Oedema
• RHS: Oedema
• University of Maryland Extension: Edema of indoor plants

General guidance, not a diagnosis. For valuable, edible or outdoor crops, check with a local extension service or plant expert. Use any product exactly as its label says, and keep children and pets away while it dries.