The soil around those plants looks fresh. Are they newly planted? If so perhaps the plant is just trying to adjust its new surroundings.

Ours looked like that, worse even, the first year. I watered them every day so I decided it was too much. 4 years later they are still there and I barely touch them. If we don't get rain, they get water once a week.

Are you watering with sodium softened water? They are more sensitive than most to sodium.