I planted 2 healthy plants of Pelargonium endlicherianum in a large container filled with scree-type soil this spring, and in the last two weeks, all foliage has yellowed and dropped from the plants. The stems seem to be turgid and green, which leads me to believe they've gone into some kind of a summer dormancy. I know they're from the Southern hemisphere, and that all pelargoniums here tend to slump during the longest, hottest days of summer, but none of the others drop every leaf. I'm keeping it on the dry side for now and watching carefully, but can't find much cultural info on the plant. Any thoughts on this behavior?