Some of the world’s great mysteries may never be solved — like how did the hosts of “Fox & Friends” ever graduate from high school? But there is one mystery plaguing a lot of gardeners right now upon which Grumpy will shine the light of knowledge and understanding — why crepe myrtles sometimes change color.

Take a look at the crepe myrtle bloom above. There’s a  teeny chance it’s supposed to look like that (for example, one called ‘Prairie Lace’ has deep pink blossoms edged in white). However, the much more likely culprit is the weather.

Red is the rarest naturally occurring color among crepe myrtles. People love red. And so two fairly recent introductions, ‘Dynamite’ and ‘Red Rocket’, have exploded in popularity (pun intended). They resist mildew, tolerate heat and cold, bloom for a long time, produce few seeds, don’t get too big (15 to 20 feet tall). They also flaunt vivid red flowers

But they share one weird idiosyncrasy. When flowers open during cool, cloudy weather, instead of opening red, they open white. And that’s when people freak out and invest all their life savings in bomb shelter carpeting.

I watched the color change in my neighborhood about a week ago. After a month-and-a-half of brutally hot temps in the high-90′s, we had a rainy, cloudy Saturday. Shortly thereafter, I began noticing red crepe myrtles with white flowers.

There is nothing you can do, including fertilizing with uranium or sunbathing nude on Mercury, to change this. That’s they way these new crepe myrtles are. So learn to love it.

Our Stinking Weather

Weather affects the colors of many flowers, not just those of crepe myrtles. Don’t you just love the way that “pink” daffodils and ”yellow” magnolias never turn that color for you because the spring is too hot? Other flowers that you wouldn’t normally think of change color too. For instance:

This phlox in my garden bloomed deep pink during the heat. Then we had that rainy weekend. When the next flush of flowers opened, a white spot adorned nearly every petal. Weird? Nope. Normal.

Anybody want to buy 5,000 yards of storm shelter carpeting? I’ll give you a deal.