January 10th: Happy Houseplant Appreciation Day!
This is Sandra with the Loh Down on Science.
You’ve heard:
“Don’t water your plants at noon, because they’ll burn!”
Botanists from Hungary’s Eotvos University wondered if sun rays and water droplets could actually fry plants. They combined computer models with experimental tests on a variety of species.
And?
Water droplets CAN cause leaf burn, but only plants with hairy leaves, like ferns. The hairs hold droplets above the surface. Those drops focus sunlight onto the leaf blade like a mini magnifying glass.
This could even spark wildfires, though the water tends to evaporate before combustion occurs.
Scientists say the same phenomenon can lead to sunburn on a hairy creature, after a swim.
So while it’s up to you to prevent wildfires, maybe Smokey should towel himself off, before giving advice!
Reference: Egri, A., Horváth, A., Kriska, G., & Horváth, G. (2010). Optics of sunlit water drops on leaves: conditions under which sunburn is possible. The New phytologist, 185(4), 979–987. https://doi.org/10.1111/j.1469-8137.2009.03150.x