Watering your garden during the heat of the day is bad for your plants. Or is it?

One of the most entrenched horticultural myths concerns wetting down the foliage of plants during the heat of the day: “Water droplets act as tiny magnifying glasses, focusing the sun’s rays so that your plants get scorched” is accepted wisdom among a large portion of the gardening public. 

But nothing could be further from the truth.

In Australia, in order to prevent scorched fruit on a 40-acre Granny Smith apple orchard, an overhead misting system was installed. Sunburn loss was...