Brown patches

I reasently planted marathon II sod in my backyard about 4 weeks ago.  I began to see brown pathes one week after installation.  Now almost half of my 700 sq' is with brown patches. 

All I can find is that is a fungus and that is hard to control.  I have stopped watering these brown patches.  What do I do to stop the spread of disease?  Do I seed in these brown patches?

I would alos like to know what is the best organic fertilizer?

HELP!!!

Clauida

I do not know what to tell you about the sod problem, but the Ringer brand is a favorite of this websites administrator ( Paul Wheaton ).

yes, ringer is the fertilizer of choice (mostly because it is easy to find).

As for the brown spots ...  can you send a pic? 

Have you tried to dig up some of the brown spots to check for grubs (they look like dirt maggots).