Does anyone know what is causing spots on most all of my zinnia leaves? They are planted in a teeny tiny community garden plot that is receiving a lot of run off from the plot next door. Could the spots be from over watering? (These plots are about 18” x 30” with no barrier between neighors.)
I had zinneas planted in a different though similar sized plot last year, never had issues, and had nice bouquets of zinneas all summer long. Am aiming for the same this year.