Hosts
Fuchsia species and cultivars. Also on willowherbs (Chamaenerion angustifolium and Epilobium spp.). Possibly on Clarkia (Godetia ) spp., although the importance and extent is unclear. Alternates its life cycle between these hosts and firs (Abies spp.).
Symptoms
Pale patches on the upper surfaces of leaves, corresponding to small, raised orange pustules on the lower surfaces, containing dusty orange spores. Lower leaves are usually worst affected and these shrivel, leaving a straggly plant.
Biology
Caused by the rust fungus Pucciniastrum epilobii. Orange, then brown spores are produced on fuchsias and willowherbs. The brown spores cannot re-infect these hosts, but instead cause infections on young needles of firs. These in turn produce spores that can only infect fuchsias and willowherbs. Damage to firs may be important in forestry, but it is the fuchsia stage of the lifecycle that is likely to be noticed by gardeners.
Control
Fuchsias are sensitive to the fungicides used to control rusts and should not be sprayed. Remove willowherb hosts from the vicinity. Remove infected leaves as soon as damage is seen. Badly affected plants should be destroyed.