Possibly japanese beetles. I have lots of coneflowers and lots of eaten petals, but this happens every year. It doesn't really bother me all that much so I just never bothered to investigate. I do know that earwigs are always on the coneflowers at night, and while I personally don't think they do any damage, others would disagree and just might be the culprit. Since the goldfinches are all over the coneflowers, maybe they're simply ripping the petals with their feet.

I have been growing in containers for many years indoors and in greenhouses, but not outdoors where they are exposed to the elements. I have grown with chemical and organic fertilizers in containers so i'm familiar with both. I haven't grown tomatoes in about 15 years and the last time I did, they were put in the ground. This is the first time, i'm growing them in containers and its outside. After reading your comments, im guessing that because I received an excess amount of rain for many days, that my soil ended up flushing out a good portion of the nutrients from containers. Then immediately after it was really hot and many time humid. I live in NC in zone 7b. With the excessive rain and then heat my soil may have also experience ph swings possibly locking out nutrients (this is just speculation) My soil in the containers is as follows: Daddy Pete's Organic Lawn and Garden Soil (contains manure), Bagged Oranic Humus and Manure, Mixed Large Amounts of Dirt from the ground with it. A lot of my ground soil contains a lot of clay and sand. Mixed all that together then added the following Amendments: Bone Meal, Blood Meal, Natures Blend Organic Fertilizer (Made by Miracle gro, its a green bag and its OMRI listed) Azomite Rock Dust for trace minerals Organic Lime Hollands Giants Mycorrhizae I added a decent amount of each I didn't add a whole lot because the plants were small so I didn't want to burn them and the bagged soil already had manure in it. I Mixed all that into the huge pile of dirt and then proceeded to fill the bags with the small plants. They were fine at first then when I got hit will all the excessive rain and then hot and humid weather (84-91 Degree F) their health rapidly declined. I was trying to stay organic like I said, hopefully that can workout. I appreciate everyone's help Im also going to add more soil to the bags and or transplant them into bigger bags if the plants bounce back. I just didn't want to do it because of their health and especially since I thought it was a pathogen or fungi. I didn't want to waste all the money on dirt if I had to toss all that soil out.

Your question about coneflowers overwintering was asked previously in houzz. HERE is the link to that question and the answers given. Unfortunately, I also have been unable to get coneflowers to come back for a second year. There are at least 6 species of the genus Althea, but I always picture SHRUB ALTHEA (Hibiscus syriacus) which grows 12 ft tall and nearly as wide. This althea tends to get pot-bound. If your water is hard it's also likely alkaline which can make your potting soil more alkaline over time. Shrub althea prefers a pH between 5.6 and 7.5. Although shrub althea needs 1 inch of water a week, it also does not like to be wet. Too much water causes lower leaves to yellow and die. What is good for the petunias may be killing the althea. Ideally, it should be planted in a prepared, well-drained bed with added peat and compost. Fertilize in the spring and fall, and use a fertilizer for acid-loving plants if your soil or water has a pH over 7.5. Water deeply, but allow the soil to dry between waterings.

The branch tips look healthy and I do not see any clear signs of insect issues so I think its just part of the natural cycle. Generally speaking a pre-dormancy characteristic is the oldest leaves start to get that yellow look which progresses until it falls off or you get tired of looking at them and gently pull them off (there is a right way and a not so right way to pull leaves off). Dormancy or chronic dry conditions do look much the same. Here in South Texas we actually call it the end of summer leaf drop. It typically coincides with the ending of hot summer (July - August) as we transition into a temperate climate with more rain. Historically its also about the timeframe where my rainwater harvested supplies have run dry and am having to water 5+ times per week. Once a leaf gets old and no longer offers any usefulness to the plant it will eventually fall off. This is from a few days ago under my Duke Plumeria. No harm, no issues, just the time of year and drying out from high wind and being laid over during Harvey. a Bud G.'s My Valentine showing end of summer leaf drop. Various 1 and 2 gallon rooted cuttings showing chronically dry. Brittany, Each cultivar is different in flowering. Each branch tip has the capability to produce one inflo with multiple flowers each growing season. Each inflo can continuously produce flowers for months or may just go for a couple of weeks and then dry out and fall off. The My Valentine above has been blooming since late May. Long enough that the right side of the inflo is starting to get covered by new growth leaves. Some cultivars will produce multiple inflos per tip in a season. . Generally speaking younger plants do not necessarily have the capacity to produce a large amount of blooms just yet. In my climate usually by year 3 I am seeing an improved bloom display. Some rather pesky cultivars have taken into year 4 or 5 before showing anything.