I recently purchased 2 hawaiian schefflera plants that are appx 3 feet tall, and 2 feet across: the plants were beautiful and healthy. I watered about every 7 days, then got the bright idea to feed them. Shortly afterwards(1-2 days) black spots began to appear on the leaves, then leaf drop. They are actually green with a large black spot when they fall off. I have also been misting every few days. Which I have learned may cause excess moisture and black spot. It's primarily the upper leaves, which are most likey to recieve the misting. Am currently waiting for the soil to indicate that it needs to be watered. The plants are very plush, the leaf drop is barely noticeable, but I'd need good information going forward. I purchased new pots/soil thinking that I may need to check for root rot. The leaves are not yellow at all. Indirect sunlight for 12-14 hours each day.