Spots and patches on houseplants

Pale rings and blotches on leaves

Likely cause
Cold water splashed on the foliage.

What to do
Water from below with room-temperature water and keep the leaves dry.

Brown dead patches in the middle

Likely cause
Dry air, or the dense mat rotting where air cannot reach.

What to do
Raise humidity, thin it out if it gets very thick, and water from below.

Pale scorched patches

Likely cause
Direct sun on fronds built for forest shade.

What to do
Move it back to medium or bright indirect light.

Pale scorched patches

Likely cause
Sunburn after a sudden move into strong light.

What to do
Acclimate it over a couple of weeks rather than moving it into full sun at once.

Bleached or scorched patches

Likely cause
Direct sun. This is a deep-shade plant.

What to do
Move it well back from the window; it is happiest in low light.

Greyish or scorched patches

Likely cause
Too much direct sun.

What to do
Move it to low-to-medium indirect light; it tolerates shade better than glare.

Leaves splitting along the ribs

Likely cause
Normal. Banana leaves tear in moving air; it is how they survive wind.

What to do
Nothing to fix. Keep it out of strong drafts if you want the leaves to stay whole longer.

Brown patches on the leaves

Likely cause
Sunburn, or root damage from staying too wet.

What to do
Keep it in bright indirect light and check the roots if the soil has been soggy.

Brown spots in the leaf center

Likely cause
Root rot from overwatering — the classic fiddle-leaf complaint.

What to do
Let the top 2 inches dry, make sure it drains, and water on a strict schedule.

Bleached or scorched patches

Likely cause
Sunburn from a sudden move into full sun.

What to do
Acclimate gradually over a few weeks. The damage is permanent but harmless.

Scorched patches on the fronds

Likely cause
Direct sun.

What to do
Move it to bright indirect or medium light, well out of direct rays.

Brown marks on the fuzzy leaves

Likely cause
Water sitting on the felt-like hairs, which then rot or scar.

What to do
Water at the soil only and never mist. Marks are permanent but harmless.

Pink sections browning and dying

Likely cause
Pure pink tissue has no chlorophyll and cannot sustain itself, so it burns and dies back.

What to do
Normal and unavoidable. Aim for leaves with both pink and green, and keep it out of direct sun.

White powdery film or spotting

Likely cause
Powdery mildew from damp, still air.

What to do
Improve airflow, keep water off the leaves, and remove affected foliage.

White powdery patches on the leaves

Likely cause
Powdery mildew — the classic rex begonia problem, caused by wet leaves and stagnant air.

What to do
Never mist. Water the soil only, improve airflow, and remove affected leaves.

Brown patches on the leaves

Likely cause
Sunburn from direct light, or cold shock against a window.

What to do
Pull it back from the glass into bright indirect light.

Black or brown patches at the base

Likely cause
Overwatering — the most common way a mounted staghorn dies.

What to do
Let it dry substantially between soaks and make sure air moves freely behind the mount.

Traps turning black

Likely cause
Tap water is the usual culprit. Individual traps also blacken with age after catching a few meals.

What to do
Use only distilled or rainwater. Trim dead traps; a few blackening at a time is normal.