Hi forrie,

" I suspect it might be fungal and/or bacterial. "

It would help if you could post pictures of your peaked petunias. Right now we haven't ruled out nutritional or environmental causes. How many hours of sun do your petunias get? What do you supply in the way of nutrients? As for the petunia caterpillars, your response there may depend on whether you are an organic gardener or not.

ZM

Several things help keep petunias blooming....1) deadheading, meaning removing the faded flowers and the seed pods located at their base and 2) cutting back. Many petunias get straggly by July. Cut the stems back by half and give them a good feed. In a week or two, you'll have renewed blooming.

its not really worth investing in fighting disease .. if in fact it has any ... with annuals ... IMHO

and you have to be very careful ... in deciding its just not mid summer aging.. and uglies ... which is what calli alludes to ...

you are past the pinching spent flowers off .. just cut back very hard [look for a very small bud where an old leaf meets the stem.. and cut just beyond it ... the cutting will trigger this bud to become dominant ... and with no insult to the root mass ... and half the canopy gone... thats a lot of roots to feed new growth ....

... also juice it with some diluted water sol fert fert ... and ...

give us a pic to support our speculation ...

ken

I should have posted pictures, too; duh, sorry about that! I guess I was just trying to get my question out quickly. Here are some below.

I don't believe this is seasonal aging. The reason why is that it's fairly sudden, the flowers become thinner and there's dead leaves everywhere. The foliage thins out and doesn't have the vivacious look it has had all this time. My neighbor has the same problem with her (store bought) petunias.

The caterpillars are coming and I've yet to figure out how to get rid of them. I was using this Bayer white-fluid pesticide, which had minimal impact. Someone suggested a powder (bacillium or whatever the heck it was) to deal with caterpillars.

Thanks all!

I went ahead and pruned a bunch of ragged branches in the potted plants, to see if that will help. And, added some fertilizer - the tomato fertilizer seems to be their favorite.

So, in absence of any other useful information, they continued to wither away and branches die. I gave in and took the scissors to all of it; maybe some will grow back. But, I've no idea why this happened, which is really frustrating.

I bet they will grow back. My petunias looked awful about a month ago, and I cut all of them back to short leafless stubs. I wondered after I put the shears down whether I had killed them. Nope. They have grown back lush, green and healthy, and are blooming.

They seem to be growing back, yes. In the process of cutting them back, I believe I also eliminated those nasty caterpillars that get on them every year -- I still don't know how to treat that problem, either. I've tried Bayer pesticide and even pouring some cold brew coffee (lots of caffeine).

Conversely, I had a pot outside that had petunias that would start growing back after winter. I thought that was rather interesting, especially for zone 5 here in New England. Most of the do not :)

I have read that you need to keep pruning petunias throughout the year. But if I can just figure out how to keep these pests off my plants, I think they will fare better. This year, I think some kind of fungus or microbe attacked them in addition to caterpillars.