Over the course of the summer, many of my Fuchsia plants have developed rust and rust damage. While rust is not a new phenomenon to Fuchsia, it is not something I've been troubled with over recent years. The result of a rust attack is to leave the plants looking poorly, with discoloured foliage and a lack of good shapely flowers.
Typically rust appears to us gardeners during the summer as 'urediniospores', a rust fungi in the form of pustules, typically light coloured en masse on the underside of leaves. This particular rust in question (as there are many types) is called 'Pucciniastrum epilobii'. This same rust is also frequently seen on willowherb (Epilopium). The spores are encouraged by high humidity, and are spread by rain splashes and air currents.
As mentioned, willowherb is also a host of this same type of rust, which is known as a method for the rust to overwintering, leaving it ready to spring back into action on Fuchsia plants in spring. Fuchsia rust can also overwinter on the foliage of non dormant plants, and it can also overwinter as mycelium overwinter in rootstock.
While there are various fungicide sprays that can be used to assist the control of rust, Fuchsia foliage is prone to damage and most articles I have read advise the use of chemicals. Instead, the advice is to remove and destroy affected leaves, as quickly as possible before the fungus spreads, and discourage the development of lush growth.
For my part, looking at 2017, I am considering taking some rust free cuttings to create new plants, and discard some of my older plants. For now though, I'll continue to pick off and destroying affected leaves, and try to ensure good growing conditions for the future for the rest of this year.
Helpful books for this blogpost, and for further reading include:
Encyclopaedia of Gardening, from the RHS
The Organic Garden Book, by Geoff Hamilton
Principles of Horticulture by C.R. Adams, K.M. Bamford and M.P. Early
Pests, Diseases & Disorders by Stefan Buczacki and Keith Harris.
Also, check out http://www.fuchsiasinthecity.com , which is a helpful website on all things Fuchsia.