What is causing this type of plant death?

This is a yellow trailing verbena, I planted it 3 weeks ago from a 2 quart pot, from a very reputable nursery. The purple verbena from 6 packs 4/6 are dead in the same area. The other 2/6 are

Here is another picture

I would guess transplant shock. If you can rig up a little shade over the plants that are still alive that may help them since sun beating down on them particularly on a warm day is working against them. And also make sure you're watering appropriately. You don't want to let them dry out obviously, but a lot of times it's easy to accidentally overwater newly transplanted things. People see the plants wilting and think they need more water, when in fact there may be plenty of water in the soil and the plant's little roots just can't take it up fast enough, so the plant wilts. So make sure you check the soil before you water--if it still feels wet then you don't want to water even if they look like they need it.

Thanks Ecrane - The same planting arrangement 5' away does not shoe the same signs. With that said I will check the moisture content. Wilt is not the issue, yellowing of central leaves and them curling is what I am seeing.

Plants won't always wilt, that's just something that many of them do and it makes gardeners water more than they ought to which then makes the problem worse. Your symptoms are still consistent with transplant shock. There are a lot of factors that contribute to how severe the shock will be, perhaps your group 5 feet away gets just a pinch more shade, or the drainage is slightly different, or you didn't damage the rootballs quite as much when you were planting them. The only other thing that I can think of is if you have gopher problems (or other underground critters that chew on roots) then it could be someone's munching on the roots in that area but not in the other. But given that you planted them recently and your days are probably quite sunny and relatively warm, transplant shock is the most likely scenario.

Do you think B1 would help?

I think people have had varying degrees of luck with things like that--some people swear by them and some people say they don't do anything. But unless you overwater the plants in the process of adding it, then it can't hurt so it's worth trying. Appropriate watering though is the #1 thing you can do to help ensure that they pull through, if you are not watering it correctly then the B1 won't fix things, but if you are watering properly then it can potentially give them an extra boost. I'd still consider rigging up some shade over them if you can, that can make a huge difference as well.

I will have a problem with shade at the moment because of the wind we have going on.
It looks like my origonal message was not sent complete. I went into a description of this particular bed, how I prepared it, and that the plants in this bed last year really struggled. That is why I went with hardy plants like verbena. I questioned maybe something was under my top 6" that could be leaching up?
I'm going out to see if I can shade the plant.

Wind could be contributing to your problems too--it dries plants out and increases the whole water stress thing that newly planted plants are already going through. All still part of transplant shock, but the more factors you have working against you the harder it is for the plants to get established. It would help to know what you had tried there last year, but if you planted at the same time of year (or later) and had the same conditions with wind and sun, etc, etc then it could be that they were just never able to get established. Even though I always advise against it, every year I end up planting a few things during the late spring or summer even though I know better, and every year a few of them will make it, but my success rate is much lower than if I plant in the fall or very early spring. I've got those same factors that you do--sun, wind, etc and sometimes you can do everything as right as you possibly can and those factors will still win out and kill the plant.

I got shade by using a large broken pot to cast a north shadow.
The moisture feels right, not wet & not dry.
Wind is transient here, not an on going problem. I tried pink girl tomatoes, eggplant, and jalapeno peppers planted late, mind you, maybe June. It is one of my sunniest and hardest soil spots, thus the gypsum.

Hopefully the shade will help them get settled in. For your plants last year, I don't know whether veggies would have normally done well in that bed, but definitely in your climate planting in June you're probably going to fail more than you succeed so even if they could have done well under other circumstances I think you planted them too late.

I'll keep you posted on the beds progress. Thank you for your advise and time!

I'll keep my fingers crossed that they pull through for you!