replanting in flower bed in which zinnias acquired fungal infection

Question

Hi! I appreciate your website so much–thank you!! I had a lovely bed of dwarf zinnias last summer that developed a fungal infection (alternaria?) and finished off the plants in a short timein late summer. I understand that planting too close, and overhead watering/rain causes moisture to stay on leaves, hindering air circulation, thus causing the infection. Watering at ground level is ideal, but rain is a given.

Am I assuming that the fungus is still in the soil in this bed? E.g. would I be ill advised to plant zinnias again in that bed this summer, or should I choose another annual?

Answer 1

I would choose something else. You can apply dolomitic lime and wettable sulfur to the soil to kill anything off, but sometimes this vigorous disease will not be killed. It is best to choose something unrelated to plant in its place.