The trees are all dwarf type. Our weather has been cooler than some years with highs usually below 85 degrees. Rainfall has been more abundant than usual: about 9 inches in June. In dry periods I water according to seller's instructions. The spot goes thru cycles where a group of leaves yellow, then are blown off by winds. This is repeated when another group of leaves yellows. The percentage of the total leaves on the trees that yellow is high, perhaps 33%.