with Annie, the fallen leaves are a source for continuation of the disease, quoting from University of Illinois Extension:
http://web.aces.uiuc.edu/vista...
"The black spot fungus overwinters in fallen leaves and in lesions on infected canes. White, slimy masses
of microscopic spores (conidia) produced in diseased tissue are splashed by water or wind-blown rain
from fallen leaves and cane lesions to the opening leaves in the spring......."
"Carefully collect and compost or burn all fallen leaves in the autumn and again before the new growth commences in the spring. Where feasible, removing infected leaves, especially during early to mid-season, will further reduce the spread of black spot."
