What nutrients are your plants getting?

If you don't find pests, it may be nutrient deficiency.

First pic looks like flea beetle damage just Google then click images then type in flea beetle damage. Flea beetles are so tiny and jump at a dime so hard to see unless you babysit the plant for a few hours or setup a sticky trap to see exactly what you are dealing with.

Second pic soil looks sandy and roots could be compacted and preventing uptake of nutes. Any reason for the sand? Did you add or is that the type of soil around your area?

If my plant(s) looked like that first picture, I'd think it's a pest of some sort as well. I like habjolokia's idea of sticky traps to hopefully see what you're dealing with.

I also wondered what they were planted in. That could be the problem. I think there's something about the soil it doesn't like.

I put the recommended amount of 19-19-19 to my whole garden area about a month ago, and then tilled all of it up.

I looked up Flea beetles. It looks like of like the damage to my plants, but I don't know about the discolouration of the leaves. Maybe a nutritional deficiency along with the beetles too?

As far as the soil goes, we live in about a 100 mile area that is really sandy. Haven't had any problems in the past with any of my plants growing in it though... This is the first time.

Do you recall any new changes from how you conditioned the soil from previous years to this year? Did you always add the 19-19-19? Maybe check the PH also of the soil thats where I would start before making any changes, be sure to find out what's causing the problem before trying to throw nutes at them.

The only new change besides the normal 19-19-19 every year, is I added a pick-up truck load of horse manure to it during the winter this year. The only change I've seen from it is I now have a ton of grass in my garden this year.

How would I go about checking the PH level without sending it off to the Clemson Extension? (Local university agricultural department) for testing?

You can Google soil PH tester will come up with many for sale. Amazon.com also has some also.

Good call habjolokia on putting out traps and suggesting it may be flea beetles at least for the plant in the first image.

Why I slanted towards a possible nutrient problem was the second plant image, it looks like a narcosis issue developing.

Here's a shot of one of my past plants that suffered from marginal necrosis, the same browning/dying at the leaf edges:

Bill