Expert: Ronald B Persaud - 6/16/2009

Question
my lawn has red thread what fertilizer do you recommend and how else do I treat it I live in long island new york

Answer
I have no experience where this disease is concerned but the following is quoted from a Cornell University publication at this site.
http://plantclinic.cornell.edu/FactSheets/redthread/redthread.htm

"Do not allow thatch levels to accumulate. Use resistant varieties of Kentucky bluegrass (Ascot, Classic, Dawn, Eclipse, Princeton, Trenton), perennial ryegrass (Lowgrow, Lynx, Navajo, Passport, Precision, Rivierra II, Shining Star, Target), and fine fescue (Biljart, Bighorn, Reliant, SR 3000, Waldina).

Where disease is severe, fungicide applications may be necessary. Although Red Thread is not often a problem on lawns, if it does become troublesome, homeowners in New York State may apply a registered fungicide to manage this disease. In spring or fall, apply Bonide Fung-onil MPF Conc. (chlorothalonil), Spectracide Immunox MPF (myclobutanil), Bayer Advanced Fungus Control for Lawns RTU Granules (triadimefon), or Heritage (azoxystrobin), or apply a registered fungicide containing the active ingredient propiconazole according to label directions."
I hope this helps you.