The summer of 2010 shouldn't be too distant of a memory for most and if you remember correctly, most of NC ended May on a very wet note. This was followed by one of the hottest summers on record. This series of events led to widespread cases of Pythium root rot on creeping bentgrass putting greens, especially for those who did little to nothing to protect their roots from Pythium during May.
With all that being said, you should be applying products for Pythium root rot prevention RIGHT NOW. Doing so now will save you money and headaches come summer.
For more information about Pythium root rot, including control recommendations visit: http://www.turffiles.ncsu.edu/diseases/pythium-root-rot
Remember that Pythium root rot is a soil disease, so you MUST water your applications in to be effective.