Originally Posted by LawnsharkMB
Where are you located? I'm in Myrtle Beach where the temps are getting down in the 50's at night and the highs are in the 70's. we still haven't put out pre emergent because a guy at JDL told the owner to wait a couple more weeks even though most companies and golf courses have already put it out or are doing so now.
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^^^^^^ This is your biggest problem ^^^^^^^^
To answer your original questions, I usually look for a calendar date when making the fall applications. Annual bluegrass germinates most rapidly when soil temps at the 2" depth are between 68 and 72 F (Clemson and NCSU research), with germination dropping to near zero when soil temps at 2" depth are below 58 and above 78. Because this can vary between properties and location within a property (shady areas, etc), I look for the calendar date that will be close to these temps, then back up my start date to allow me to treat my customer before this prime germination period.
But, you're main problem is proably basing your decisions off the JDL guy. His job is to sell product, not provide service to your customers -- that's your job. I've met a lot of really nice guys at dsitributor locations over the years, but I wouldn't put my business decisions in their hands.
Since you're in Myrtle Beach, annual bluegrass will probably germinate later in your area than it will for those of us farther north or farther inland. My biggest caveat would be to match your application rates to soil type. Snady soils generally need a higher rate or more frequent application than heavier soils.