Question
i just bought 20 crepe myrtles 4 to 5 multitude  trunk stile some of the leave are turning to yellow  why  ????? bob

Answer
Dear Bob, Your crape myrtles are not getting enough water.  They will need to be watered probably every day in this heat for several weeks and then probably every other day or every three days.  Some leaf yellowing is normal and crape myrtles just don't have many pests or diseases, other than powdery mildew.  With this disease, the plant looks covered with white on the leaves and to get rid of it, spray with a lightweight horticultural oil.  Other than that, just keep them watered and they will be okay.  Crape myrtles are very forgiving compared to many plants; I have seen them lose all their leaves and once the watering improves, they leaf back out.  I live in Texas, so we have lots of crapes here too.  Your crape myrtles should improve, just keep them watered.  If you have bought large trees, over about 8 feet high, then they will need to be watered for several minutes apiece to make sure that the water soaks all the way down the roots.  I hope this information helps.  Good luck, Melissa