Answer: In my experience, watering in the heat, even in bright sunlight would not cause such widespread and uniform problems over such a broad range of different plants. However, burned edges and wilting could be the sign of an accidental herbicide drift, overfertilizing, a late frost, flooding, or some other unusual occurrence affecting the general area of your garden. With some detective work perhaps you will be able to determine the cause. I'm sorry I can't be more specific.
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