Misting the leaves with water is fine. The myth goes that watering during the day will cause burn spots on the leaves, because the tiny droplets act as magnifying glasses. The truth is that misting during the day is great for plants, but the sun will evaporate most of the water so it's wasteful if your doing it on a large scale. The burning myth doesn't hold any truth and if you think back to your kindergarden days when you took out a magnifying glass and tried to burn ants, I'm sure you've seen that you can't just put the magnifier on top of the ants, you have to angle it and create a focal point. Water droplets don't create focal points. If they did, plants would be burning up all the time and our car's fancy paint jobs wouldn't last a year.