Quote Originally Posted by nekomeh View Post
I thougt they needed it to grow. Especially ones that are supposed to produce any color or flower
different doses of UV-B radiation applied to the two species Avena fatua and Setaria viridis induced changes in leaf and plant morphology. It was a decrease of plant height, fresh mass of leaves, shoots and roots as well as leaf area. Besides, it caused the leaf curling in both of the species.
http://www.cazv.cz/2003/PSE3_03/8-zuk.pdf

UV-B radiation has adverse effects on growth and metabolism of many plant species due to the high absorption affinity of macromolecules such as proteins and nucleic acids in that wavelength.
SpringerLink - Abstract

I could keep going all day long. If it was true that plants needed UVB, then nearly every greenhouse, dart frog terrarium, planted aquarium, houseplant on a windowsill, etc. would be a failure. Not to mention the fact that the vast majority of fluorescent tubes are made from non-UVB transmissive glass, meaning that all those T5HO grow light systems that hydroponic growers love would be a big scam. Yet for some reason the "plants need UVB" myth keeps making the rounds of the reptile and amphibian forums...