It looks like the soil is a clay mixture? Native soil?
If so Bev's suggestions of adding amendments would be beneficial. For clay soil some of our Pacific Northwest compost, grit and course sand added would work. Also top dressing them with chicken grit will help to cool their roots on hot days and keep the moisture away from the leaves. You will need to place the grit under the leaves, that should keep them from rotting. I don't water every day. Once a week deep watering would be more helpful to the plants.