Question From: Aurora, Colorado, United States
Q: Mounds are developing in the lawn. Digging underneath reveals large white spongy structures covered with brown root like skin with root hairs.
Yiuck! I have no idea what's growing in your lawn. Sounds like some sort of fungus. I'd dig out a sample and take it to your local garden center that specializes in lawn products for a more accurate ID and form of control. Best And Happy Yardening, Nancy