Septoria leaf spot—Septoria spp.
Several dozen Septoria fungal species occur in the United States. Each causes round, angular,
flecked, sunken, or irregular spots on mostly older leaves on a different group of closely related hosts.
Aspen, azalea, cottonwood, hebe, and poplar are commonly infected. Cankers may develop on the branches
of certain severely infected Populus species.
Prune out and dispose of infected wood in the fall. Avoid overhead sprinklers, which splash spores onto
the plant, or irrigate early in the day so that the foliage dries more quickly.
round spots are characteristic of septoria