wrote in message
oups.com...
I have a spot in my flower garden that suffers from some kind of fungal
disease, perhaps powdery mildew. In late winter I cut back my scabiosa
and coreopsis to the ground, and they start off the season fine. But
by mid-summer they start showing signs of disease. The problem is
exacerbated by the fact that this small area of the garden is watered
by the lawn sprinkler instead of dripline irrigation like the rest of
the garden. Is there any way to eliminate fungal disease from an area,
or at least give the plants grown here a fighting chance?

In addition to changing the irrigation and applying the fungicide, you might
take a couple more steps. First, if you are going to use overhead
irrigation, do it early in the day so the plants have a chance to dry before
evening. Also, I find plants that are prone to powdery mildew, like
monarda, respond well to a mid-season shearing. It delays the bloom time,
keeps the plants more compact, and at least delays the onset of the mildew.
You might also consider relocating the mildew-prone plants to another area
and putting mildew-resistant plants in the area that gets the overhead
irrigation.