mold mildew

by Sage
(Penticton, British Columbia, Canada)

I have a constant mold/mildew problem in my garden. I live in a very dry climate and use a soaker hose to water. the mold affects my echinacea, columbine, rudbeckia, sunflower, but not the tomatoes. any organic advise would be great.
Thank you,
Sage

Doug says you might want to start with the article on powdery mildew - and then the one on botrytis.

The cultural care details about full sun, good air circulation and good spacing of plants is critical in prevention. Not to mention super plant maintenance.

If you live in a dry climate and you still have these mold and mildew issues, your cultural care likely needs some attention.

I also note the plants you mention as having the problem are those that are more susceptible to it and regularly get it in almost any garden.