That does not look like any kind of insect damage I've ever seen. Looks fungal to me.

then I guess Bonide Eight won't work for it. I'll have to get some fungal spray. Anyone know what kind works best?

My feeling about stuff like that is that if it's not really bad and is not killing the plant, ignore it. Gardens don't have to be perfect.

Compost tea would probably be as effective, if not more effective than some 'cide.

cut off the worst leaves.. and be done with it ...

homeowners have the potential to be the greatest polluters on the face of the earth.. thinking there is a chemical solution for every slight problem ...

i see no negative impact on the plants in the picture ...

BES's are field/wildflowrs.. they are not foo foo .. and really dont .. in most cases.. need any solutions.. they live in the prairie ...

to my non-scientific eye.. what you are seeing is a secondary problem to some insult to the leaf a few weeks back .... so there is nothing there but a damaged leaf.. for a fungus to come along ...

any history of a hail storm ... a few weeks back??? .. just enough to break the leaf surface.. but not otherwise knock down the plant ????

look deep into the picture.. and a vast majority of the leaves underneath have nothing wrong with them... if it were a disease.. why isnt the whole plant effected????

and in that pic.. it looks like the largest oldest leaves are the damaged ones.... are the growth tips damaged???? what happened back when these were young???

just think long and hard ... before you resort to any applications... chemical or herbal.. or organic ... most of the time .. it just isnt necessary ...

good luck

ken

I think your nursery man was correct. It is one of the squillions of leaf spot fungi. I'm with lacyvail. I would just ignore it. Just remove leaves you consider particularly unsightly and clear up well at the end of the season.

Here is a link that might be useful: May be this one?

I agree with Ken and Flora, remove the worst leaves and don't spray anything.