Hi, one of our clients sent me this picture. I never seen this problem. He has several of our plants, and only has this one with a problem. Any suggestions?
Ther's a terminology problem here: Is that a Ponytail Palm? It could never be a hydroponic plant, it is a desert plant and would rot, muy pronto.
I thought the same thing Michigander. Hydroponic ponytail palm sounds like an oxymoron to me. I can't imagine why one would want to grow a caudiciform plant hydroponically. I've had similar markings on orchids growing in sterile media with only simple fertilizers. They weren't getting enough of some element or another in a limited artificial media. The identical clones right next to them in complex media/fertilizer were doing fine. So those markings are another reason to wean this plant back into a traditional soil culture. If it can survive the transition I'm pretty sure it will quit throwing leaves with those markings.
I can believe it would survive just sitting on your driveway, unless of course it was too wet, like in a low spot. You could treat it like an air plant for some amount of time and/or flushing it once a week, but too much water is a no-no and asking for trouble. I'm usually pretty successful when I ask for trouble.