Question
I have three Aspen trees in my front yard in Carbondale, Colorado. We began noticing fungal looking growths springing up throughout the yard and destroying the grass (no grass growth where these come up). The growths could be broken apart using your fingers down to a point. I took a few pieces to a local Nursery and asked for suggestions. They sold me a bottle of Sucker Stopper RTU with instructions to cut off the growths and then spray the area with Sucker Stopper. I did this for most of them, but out of sheer ignorance cut two roots and sprayed the ends that led back to the trees. I am afraid the trees are now slowly dying. Besides feeling awful (I figured there were many roots and cutting two would do no harm), I am concerned about losing these beautiful trees. They don't look healthy and have been losing leaves much too early for this time of year. Is there anything I can do? Possibly cut the root again back from where the Sucker Stopper was sprayed and hope they grow again? They are about 22" to 25" in diameter at the base and about 30' tall. Thank you very much!!

Answer
I do not think it was the sucker stopper. This is made from the plant growth regulator napthaleneacetate (NAA). And is used to stop the plant from putting out suckers of new growth. I think something else is wrong. The grows should have been little green plants and should not have bothered the grass. What you described sounds like a fungi growth.
Do not cut any more roots thos has nothing to do with sucker stopper. I think it is a combination of weather and root disease problems and really needs someone to look at this on the ground.  

I would suggest you contact the Colorado State Extension Service and ask them if someone could come take a look at your problem on the ground. Sounds like to me a root disease problem not a sucker problem. Here is their web link to the contact page for the different county offices. If you can not get them I would try the Colorado State Forestry agency and ask one of their Foresters to take a look, Here is their web contact page

http://csfs.colostate.edu/localforester.htm
Colorado State Extension http://www.ext.colostate.edu/cedirectory/allcounties2.cfm