I left leaves around my yews for insulation over the winter because I gave them a hard rejuvenation cut last spring. There’s a shimmery bluish mildew in the soil now and it took on a strange texture like the surface of the moon. It doesn’t appear there’s any mildew on the yews. In a panic I removed the leaves today. However I put compost from my brother around the yews during the summer. I was careful to keep it away from the canes. I read that compost could cause this? Thank you in advance for any information and advice you can offer.