No this isn't about a collectable trading card game or video game where you need lightning to destroy them, although I do know a little about that too. This is about they type of water used for different plants.
You might remember a few of the blog entires I did about wateing with ice. This takes care of some of the chemicals in the water like chlorine but mainly it was for the temperature of the water so that some of the plants like broccoli wouldn't bolt so soon. If you keep the roots cool then it thinks that it still hasn't warmed up yet. Plants often depend on the temperature of the roots vs the temperature on the branches/leaves to know when the right time to do things is.
This is one reason a good cold spell on citrus produces a better crop. the roots get a chance to be cold and therefore can reset the cycle of growth better.
You know... that seems like a really good experiment for my key limes. I think I'll freeze one in the deepfreeze for a few hours and then keep the soil cool with ice to see what happens. Must be careful though not to entirely freeze it solid, I can't imagine that working well. They are still tender.