Whoa!!!!!!!! Don't use any kind of weed/grass killer on the lawn to get rid
of fungi. Mushrooms, toadstools, and other fungi feed on organic matter
which they either aid in breaking down (benefit the local plants) or destroy
the living plant tissue. B/c they're growing in a crescent shape indicates
the fungi are living on something below the soil (root, limb, construction
debris). You might want to remove the source. Are they destroying the
grass/lawn? If so, then you can apply a fungicide to the area and several
feet around it to inhibit fungal spores from developing. Ifi no damage is
occuring, then welcome them, as they're releasing nutrients back into your
soil for other plants to use.
"Gerry Campbell" wrote in message
news:fH7zc.713959$Pk3.294970@pd7tw1no...
How do you get rid of mushrooms growing in your grass...I hava a crescent
shaped patch I can't get rid of and I need some ideas on how to kill these
things, short of using Roundup.

Thanks.

Gerry