said by Lurch77:I do that for winter maintenance not for mold. Lower the grass down then overseed/lime/fertilize/etc. so when the snow melts the following Spring everything grows back better then before. said by Sennheizer:
I mow the lawn down to 2" for the last mow of the season before Winter.
There is a lot of conflicting advice around the web concerning this. So I asked about it on Toro's FB page last fall. They forwarded the question to their agrostologist (scientist that studies grasses). His answer was that there is no reason to make your final cut short. Snow mold is the concern people have with the taller grass over winter. But as long as you raked leaves and debris in the fall before it snows, and clean any leaves and debris left come spring snow melt, there is nothing to worry about. I left mine normal height last year, and my spring lawn was magnificent.
He also pointed out that snow mold is worse some years, and not so bad other years. And it doesn't matter if the grass is 3" or 2". Either one will get it if you don't keep the lawn clean before snow cover, and ensure it is clean immediately after snow melt.