my fibrous rooted begonias are dying
By Bobrees
Swansea,
United Kingdom 
the leaves start off with brown /copper macks which engulfs the whole leaf and then the whole plant and the plant just deteriorates
21 Jul, 2009
Answers
If the "brown, copper" marks can be rubbed off, and are sitting on top of the leaf, it might be a form of rust, a fungal infection, for which you can get a fungicide treatment spray.
21 Jul, 2009
Are you sure you aren't wetting the leaves when watering? You should always only water the compost with begonias, I was always told.
21 Jul, 2009