a fungicide will only work.. if it is IDd is a fungus ...

we need a pic to help you ID the problem

ken

Ken_Adrian, thank you for your reply. This first picture is of the zinnia seedlings. The second picture will also be of the zinnia seedlings. The last two pictures are of the garden phlox and coneflower leaves. (All in the same garden.) I did try spraying a fungus spray last night, so if you see any white on the leaves in any of these pictures, that's what the white is.

This post was edited by lisaintn on Sat, May 31, 14 at 13:35

This is also of Zinnia seedlings.

This is a leaf from the Garden Phlox. With all these spotted leaves, it is starting on the bottom leaves and working it's way up.

This post was edited by lisaintn on Sat, May 31, 14 at 13:28

Coneflowers are doing the same thing. The only plants in this garden that are not affected are the Black-Eyed Susans and the Cosmos seedlings. Any ideas?

This post was edited by lisaintn on Sat, May 31, 14 at 13:29

Excess moisture from any source promotes leaf diseases on zinnia and many other plants.
Management is to keep leaves as dry as possible. eg: space plants to allow for good air circulation; water at ground level; if watering overhead, allow adequate time for leaves to dry before night fall.

Might take a look at this from Penn State
http://extension.psu.edu/pests/plant-diseases/all-fact-sheets/zinnia-diseases

Here is a link that might be useful: zinnia diseases

This post was edited by jean001a on Sat, May 31, 14 at 22:22

So would the zinnia diseases also be affecting the phlox and coneflowers as well?

Sorry. Double posting.

This post was edited by lisaintn on Sun, Jun 1, 14 at 12:18

Here is an older Gardenweb post that is similar regarding the phlox fungus and identifying the type.

Here is a link that might be useful: black spots on garden phlox