Why does my fiddle-leaf fig have spots on the leaves?

On a fiddle-leaf fig these are separate spots, round or angular, brown to black, scattered over the leaf rather than starting at the edge. Some have a yellow ring, and some look water soaked and slightly translucent when held to the light.

The most likely cause, as the entry says, is bacterial leaf spot, which spreads on wet leaves in still air. The NC State plant toolbox lists bacterial and fungal disease among the plant's possible problems. Spots that look water soaked, are angular because the veins stop them, and spread faster than the others point to bacteria. Round spots with a yellow halo, sometimes with tiny dark dots in the centre, that spread slowly and start on the older leaves are fungal.

To confirm it in a minute, hold a leaf up to the light and look at the edge of a spot. Then think about how the plant is watered. Leaves that are misted or splashed, in a room where the air hardly moves, stay wet for hours. The RHS recommends misting figs in warm weather, but leaves that stay wet for hours in still air are what bacterial and fungal spot want, so check that yours dry within a few hours.

Two other causes are worth ruling out. Cold damage shows as pale or dark patches after a cold night, on the side of the plant nearest the glass, sometimes in the exact shape of a leaf that touched it. Sun scorch is bleached or papery patches on the leaves facing the window. The NC State plant toolbox says brown spots may come from temperature swings near heating or cooling vents, and scorch from too much direct sun.

The spots on a leaf do not heal. What you can judge is whether new spots stop appearing, which should happen within a few weeks of drier leaves and better air, and whether new leaves open clean.

What this plant wants

The fix

Remove affected leaves, water the compost rather than the foliage, and give the plant more air movement and more light.

Read on

Spots on the leaves

The same sign on any plant, with the causes in the order they are likely.

Fiddle-leaf fig care

Light, water, feeding, repotting and the rest of the entry.

Check it in the diagnoser

Opens with the plant, the part and the sign already chosen.