church garden, change to full sun from shade

We need some help. We lost a 100 year old oak at church that shaded the entire courtyard. All of the beds are filled with shade plants, they have suffered this hot, dry summer. I'm in charge of making a change to plants that will survive in the sun, and because of budget crunches, I'm thinking plants that don't need constant watering would be a good idea.

I've learned over the years that beds with all the same or just a few types of plants work best in these large areas, but I've never gardened in full sun.

Any suggestions would be appreciated. The soil is excellent, loose and loamy. We have walks between the beds so I don't want anything that has stickers or thorns.

Thanks!

Cathy