I live in south central TX my brugs leaves are really turning yellow this year even the younger leaves turn yellow. We have been having near 100 temps. I keep them watered daily as they get really droopy from the heat and they are mostly in the shade out of the hot sun. I fertilize them every couple weeks. No mites or aphids. Can it be too much water, not enough fertilizer, too much fertilizer or is it just too hot???