One of my three elephant ears on my deck in Brooklyn(only a mile from Stack Exchange HQ) has suddenly turned yellow. I had some yellowing on it's sibling earlier in the year, which I diagnosed as excessive water and corrected. The elephant ears are originally from Costa Rica according to the nursery I purchased them from.
However, the plant in the picture was growing fast and green until 3 days ago when I practically bleached. We had a very wet week with thunder showers, then much high temperatures and more sun. So I would diagnose it as too much sun, except its neighbor is green and happy. there are two environment differences between the two elephant ears: - different pots so slightly different soil and drainage - the green elephant ear gets more shade from the yellow elephant ear, and a royal palm.
- is the yellowing an absence of chlorophyll? If so, how does excessive sun reduce chlorophyll?
- would excessive sun yellow the elephant ear in a few days?