Hello from Arizona

Piggy, it could be a combination of things including stress. New transplants need more often watering in their first year, while being established, and fair best when planted in very early spring or Sept. so they can adjust before the heat or cold hits. And raised beds require more water, still. I'm not sure of the locations of your beds but most of the plants you listed need shade and...depending on the type of petunia, verbena and vinca...may not hold up to our heat. (Many plants tags say full sun but many times that actually means part shade or shade for us in the low deserts.)

This heat that's about to hit (108 by Sunday) will usually require watering small new transplants one gallon each, 3x a week. Established plants can take more water applied less often. One last investment that's well worth it is a water meter. It takes the guesswork out of watering and a small one costs only about $10.

There are better drip guidlines available, but this is a very general one for drip watering amounts (most watering guides refer to established plants only): http://www.wateruseitwisely.com/waterguide/plant-guide.html.

When I relandscaped a few years back I put in around 100 plants on drip. It takes a while to get to know your new plants and the "feel" of a new garden, but it will come! :)