Some of the large plane trees in my neighbourhood show much of their new growth withered by powdery mildew. Is there an effective way to treat it that involves more than cleaning up the fallen leaves and less than removing the trees altogether?
treatment shouldn't really be necessary. Planes are somewhat prone to powdery mildew at this time of year but their leaves will be a falling real soon anyways. like you said, clean up the debris and they should be ok next year.
