Old Water/New Water—What’s the Diff?

Water should be water, right?  According to my garden, that is not the fact.  My tomatoes, peppers, and okra have a definite preference for rain.

At the beginning of every planting season, every gardener dreams that moderate temperatures and  plentiful rainfall will produce a lush and bountiful garden.  By July, reality sets in and that gardener either gives thanks for a dream come true or that same gardener rises at dawn to get outside before the heat sets in to weed that garden and to water before the heat evaporates off most of the moisture.

Due to this summer’s record-breaking temperatures, I have been diligent about getting outside early with hoe and hose to care for my leafy charges.  While these green guzzlers seem to appreciate my efforts and the sleep I give up, they have a definite preference for rain vs. tap or well water. I have visited with other green thumbs, and they share this observation.  Plants like water, but they really like rainwater.

This confuses me a bit.  Well water is just really, really aged rain water. After all, that aquifer filled due to ancient rains that fell on this land thousands or millions of years ago. In all those years underground, minerals have enriched the aquifer waters, which one would think would be good for plants.  However, I suspect that may not be true, based on the evidence before my eyes.

I make sure my plants have ample water to thrive.  To reward me, they stay somewhat green considering the heat, and they continue to grow and fruit lethargically.  Give them a good rainfall, and they grow at least two inches in a few hours and set on fruit if the temperatures allow.  If I had time stop film on them, it would smoke at their rate of growth.

My initial thoughts were that rainwater delivers some kind of nutrients from the skies, and maybe it does.  What I am thinking now is maybe plants can more easily utilize rainwater than they can mineralized well water.  Perhaps, since it hasn’t been aged in Mother Earth’s cask, it slides down the plants’ metaphorical throats without any hiccups.  I guess I’d choose a glass of cool water over something aged in oak myself.  

I don’t have any real answers about why my garden prefers one kind of H₂O over another, but after several close observations this summer, I know it is true.  I guess the question now is would water collected in a rain barrel continue the natural effects of rain? That would be worth finding out in these dog days of summer.