Question of the day...when is it too late for a pre-emergent?
The answer is not, and never will be a specific date. Dates are a good general guideline, but a date will not determine the success or failure of a pre-emergent application.
Pre-emergent timing is all about soil temperatures. Once soil temperatures reach a 5-10 day average of 55+, pre-emergents will be less effective. A quick google search for soil temperature maps will pull up a number of good sources without having to go out and track it yourself. Remember to ALWAYS look at the 5-10 day soil temperature average and not just the current temperature.
As of today the 5 day average is 49, which probably gives us a few more weeks before we cut off pre-emergents.
Bottom line...get your pre-emergent down now!
For those that always procrastinate and end up missing the deadline...there is still hope. There are a few pre-emergents out there that also act as a post emergent (while weeds are young) that will buy you a little more time...more on that later this week!
