Why are there orange powdery spots?

Orange-brown spots can form on the foliage of plants as a consequence of a fungal infection known as fungal rust disease. Fungal rust disease is usually quite simple to identify due to its characteristic rust-like spots. These spots are actually pustules that contain fungal spores and can occur on both the underside of the leaf as well as on its surface.

Symptoms

• Orange-brown spots with a powdery consistency

• Loss of foliage

• Yellowing leaves

Common causes

Fungal infections tend to develop under conditions of warmth, humidity, and low light intensity. Fungal rust is no exception to this - it's often seen when leaves are kept wet for prolonged periods of time, such as after long periods of heavy rain or if a plant has been misted too much.

What to think about

Once it takes hold, it can very quickly spread. Left untreated your plant may risk dying or at least be severely stunted in growth.