Could be extreme heat, too much water, or if it is a nutrient defeciency try adding some bone meal. No expert though. Smokemaster,josh or Willard should hook you up(the experts).

KerenR, As Dave said, leaf roll is a sign of stress and the most common cause is too much water. Even though the soil surface looks dry, clay soil generally does not drain well, and can even act like a tub if you have amended a hole for planting. Have you checked soil moisture 3-5" below the surface? GardenWebber sprouts_honor (Jennifer from Cleveland) had a wonderful suggestion on how to tell whether or not you need to water your tomatoes, and I quote here: "Get a wooden dowel rod (or two) and sink it in the ground near a plant or two and leave it. Pull it out when you think you need to water. If the top is dry and the bottom is a little damp, it's time to water. If it looks dark and feels saturated, wait to water. I use this technique with potted plants that don't like being over watered and it's helpful with in ground plants too." I find that is a simple way to monitor the moisture level in the soil where it counts, at root zone. You don't say how long it's been since you planted the basil and marigold seeds, but I think they should have sprouted by now. You may need to mist the soil surface 2-3 times a day to get them to sprout, since it looks like the surface is very dry. If you just moisten the top inch or so, it should not add any more stress your tomatoes and might germinate your other seeds. If they don't sprout, you may want to start some in some soilless potting mix and transpant them to where you want them. As some of your FB responses noted, mulching will help even out the moisture and add organic matter to the soil. After you have pulled your plants this fall, you may want to till in some compost or well aged manure to improve the soil. Betsy

First off, I would clip all of them the that are yellow and partly yellow as wont revive and are no longer a positive player , are burden and can be an entry point for disease. The cause is often over watering and or under fertilizing or both. It can also be affected with shade. JMO Sey

Those types of herbicides are systemic, so pruning won't do much. The plant may or may not survive through the damage and start producing more normal foliage at some point, but your yields are going to be much lower if it does. Pruning off any foliage that gets necrotic might be a good move but mostly to reduce the chances of diseases accessing the plant through it.