Phyl, If I remember, you had cold and rainy weather for a long time early this season -- longer than we had. Cosmos are day length sensitive. Since you stated you planted these from seed, they won't begin blooming until August. They only way to trick cosmos into blooming sooner is to start them in seed trays, and plant out the plugs. This is what we do; and, actually they just started blooming about 10 days ago. Zinnia foliage is one of the favorites of the Japanese Beetles. They love the zinnias -- second only to the dahlias. Our zinnias are planted about 8" apart. It doesn't sound like yours are planted too close. And, we always give them a shot of fertilizer high in nitrogen. We have to be careful on the timing of the fertilizer because it can cause weak necks on the flowers; however, it greens up the plant and gives the plant the length we need. The Chrysanthemum carinatum I hate to tell you; but, DH plowed that under. The flowers were getting eaten all the time -- never any harvestable stems. And, lots of little bugs setting up housekeeping in all the plants. So, buh bye to the Chrysanthemum carinatum; and, hello to Copperhead. Anyway, if you have buds, you just need to give them some time. Zinnias and Cosmos are technically a late season crop.

Groundhogs (woodchucks) can tunnel under and climb over fences.

Are you trying to invite them to come back? Most of my bad fruits go in compost. Sometimes I throw them far out in the woods - that way the animals that MAY be in the area get to eat something away from my garden and dont develop a taste for coming into my garden - which if they tried, they will have to meet my two dogs. Love my dogs and spoil them with bacon and bones!

There are several possibilities. First I'd check /very/ carefully for a root mealie infestation. A few years ago some of my streps were showing similarly yellow leaves and Dale Martens hopped right in and said they probably had root mealies. Sure enough, they did! May not be a bad idea to repot, washing the roots very carefully and sterilizing your pot or using a new one - and adding insect granules to your fresh mix. You should be able to see root mealies if they are thick but they may be very difficult to see and easily mistaken for perlite if the infestation is not heavy. The other suggestions here are also good about feeding, light, temperature, etc. So check them all and make corrections as necessary.